Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cigarette smoking is an important risk factor for both vascular disease and various forms of cancer. Vascular endothelial growth factor (VEGF) is an endothelial-specific mitogen that is normally expressed only in low levels in normal arteries but may be involved in the progression of both vascular disease and cancer. Some clinical evidence suggests that cigarette smoking may increase plasma VEGF levels, but there is a lack of basic science studies investigating this possibility. We show here, using an intact porcine common carotid artery perfusion culture model, that nicotine and cotinine, the major product of nicotine metabolism, cause a significant increase in endothelial cell VEGF expression. VEGF mRNA levels were compared between groups using reverse transcriptase-polymerase chain reaction, whereas protein level changes were demonstrated with Western blotting and immunohistochemistry. Our results showed significant increases in endothelial cell VEGF mRNA and protein levels because of nicotine and cotinine at concentrations representative of plasma concentrations seen in habitual smokers. VEGF immunostaining also paralleled these results. These findings may give a clue as to the mechanisms by which nicotine and cotinine from cigarette smoking increase vascular disease progression and tumor growth and metastasis.
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PMID:Nicotine and cotinine up-regulate vascular endothelial growth factor expression in endothelial cells. 1183 60

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), produced predominantly by endothelial cells, is involved in angiogenesis and mitogenesis. Myofibroblasts (myoFb) are phenotypically transformed fibroblast-like cells found at the site of myocardial infarction. Since myoFb play a role in tissue repair/remodeling at the site of infarction, and express endothelin and angiotensin II (AngII), it was interesting to investigate whether myoFb express VEGF and its receptors de novo, and if the expression is influenced by vasoactive peptides. Primary cultures of myoFb were isolated from 4-week-old adult rat heart infarct were used in this study. Semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR), utilizing primers designed to amplify known isoforms of VEGF revealed expression of two predominant forms, VEGF120 and VEGF164 and northern blot hybridization detected VEGF mRNA of 4.5 kb. VEGF actions are mediated via two major receptors, Flt-1 and KDR, and hence the expression of these receptors was investigated. Flt-1 and KDR expression in myoFb was detected by RT-PCR, RNA transcripts were confirmed by northern blot hybridization while western blot confirmed the presence of VEGF, Flt-1 and KDR proteins in myoFb. In this study AngII upregulated VEGF and Flt-1 expression in myoFb, but not KDR; this was mediated predominantly by AT1-receptor. We report for the first time that cardiac myoFb, isolated from the site of infarction express VEGF, its receptors, Flt-1 and KDR, with modulation of VEGF and Flt-1 expression by AngII. Thus, VEGF may contribute to tissue remodeling and angiogenesis at the site of infarction in an autocrine manner.
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PMID:Cardiac myofibroblasts: a novel source of vascular endothelial growth factor (VEGF) and its receptors Flt-1 and KDR. 1267 42

Vascular endothelial growth factor (VEGF), a potent pro-angiogenic factor, might regulate the neovascularization observed in the pulp of teeth with deep caries. The purpose of this in vitro study was to evaluate the effect of bacterial lipopolysaccharides (LPS) on VEGF expression in dental pulp cells. Mouse odontoblast-like cells (MDPC-23) or undifferentiated pulp cells (OD-21) were exposed to 0-20 microg ml-1Escherichia coli LPS or 0-80 microg ml-1Prevotella intermedia LPS. As controls, mouse macrophages or gingival fibroblasts were exposed to LPS, since these cells are known to secrete VEGF. The VEGF expression was evaluated by reverse transcriptase polymerase chain reaction or enzyme-linked immunosorbent assay. The baseline expression levels of VEGF protein were higher in MDPC-23 and OD-21 than in fibroblasts or macrophages. Vascular endothelial growth factor protein expression was upregulated in MDPC-23 and macrophages exposed to E. coli LPS, but not in OD-21 cells or fibroblasts. Higher concentrations of P. intermedia LPS were required to induce VEGF expression in MDPC-23 cells. Treatment with LPS did not affect VEGF expression at the mRNA level in any of the cells evaluated. These results demonstrate that bacterial LPS upregulates VEGF expression in odontoblast-like cells and macrophages, and suggest that the regulation of VEGF expression occurs primarily at a post-transcriptional level.
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PMID:Effect of lipopolysaccharides on vascular endothelial growth factor expression in mouse pulp cells and macrophages. 1278 54

The effect of sepsis on neovascularization in fractures that follows open fractures is important to the understanding of bone and soft-tissue healing. An animal model was designed that mimics the open fracture and the clinical repair of the human, high-energy open fracture. Vascular endothelial growth factor (VEGF) mRNA levels in canine bone samples were determined in samples from days 0 and 7. Canine right tibiae were fractured with a penetrating, captive-bolt device and then repaired in a standard clinical fashion using an interlocking intramedullary nail. Animals were subject to one of the following experimental protocols: tibial fracture (group I, n = 3); tibial fracture and Staphylococcus aureus inoculation at the fracture site (group II, n = 3); and tibial fracture and S. aureus inoculation with a rotational gastrocnemius muscle flap (group III, n = 3). Bone samples were harvested on days 0 and 7 and prepared for reverse transcriptase polymerase chain reaction assay. Primers for VEGF were commercially prepared and assay products were sequenced. The assay products were associated with Genebank VEGF mRNA sequences. VEGF mRNA levels increased significantly in the fracture-alone group from day 0 to day 7 (n = 3, p < 0.05). In the fracture and S. aureus group (group I), VEGF mRNA expression decreased 79 percent (p < 0.05). In animals with fractures inoculated with S. aureus and a transpositional muscle flap (group III), VEGF mRNA expression was increased 38 percent from day 0 to day 7 (p < 0.05) and was similar to the increase observed in the fracture-alone group. These results demonstrate that S. aureus decreased the normal increase of VEGF mRNA expression during bone wound healing. Use of the transpositional muscle flap in the presence of S. aureus increased VEGF mRNA expression over time to the expression pattern observed in the fracture-alone group. This experimental model demonstrates that specific biological signals and cellular pathways are influenced by bacterial infection and type of surgical closure.
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PMID:Effect of a transpositional muscle flap on VEGF mRNA expression in a canine fracture model. 1283 90

Vascular endothelial growth factor (VEGF) is a glycoprotein that plays an important role in neovascularization and increases vascular permeability. We reported that VEGF is involved in motion pain of patients with rotator cuff disease by causing synovial proliferation in the subacromial bursa (SAB). The present study investigates whether VEGF is also involved in the development of shoulder contracture in diabetics with rotator cuff disease. We examined 67 patients with rotator cuff disease, including 36 with complete cuff tears, 20 with incomplete tears, and 11 without apparent tears (subacromial bursitis). The patients were into groups according to the presence or absence of diabetes (14 type II diabetics and 53 non-diabetics). Specimens of the synovium of the SAB were obtained from all patients during surgery. Expression of the VEGF gene in the synovium of the subacromial bursa was evaluated by using the reverse transcriptase polymerase chain reaction. The VEGF protein was localized by immunohistochemistry, and the number of vessels was evaluated based on CD34 immunoreactivity. The results showed that VEGF mRNA was expressed in significantly more diabetics (100%, 14/14) than in non-diabetics (70%, 37/53) (P=0.0159, Fisher's test). Investigation of VEGF isoform expression revealed VEGF121 in all 14 diabetics and in 37 of the 53 non-diabetics, VEGF165 in 12 of the 14 diabetics and in 21 of the 53 non-diabetics, and VEGF189 in 1 of the 14 diabetics and in 2 of the 53 non-diabetics. No VEGF206 was expressed in either group. VEGF protein was localized in both vascular endothelial cells and synovial lining cells. The mean number of VEGF-positive vessels and the vessel area were also significantly greater in the diabetics (p<0.015, Mann-Whitney U test). Synovial proliferation and shoulder joint contracture were more common in the diabetics (P=0.0329 and P=0.073, respectively; Fisher's test). The mean preoperative range of shoulder motion significantly differed in terms of elevation between two groups: 103.8 degrees in diabetics and 124.9 degrees in no diabetics (p=0.0039 Mann-Whitney U test). In contrast, external rotation did not significantly differ: 44 degrees in diabetics and 49 degrees in non-diabetics (p=0.4957, Mann-Whitney U test). These results suggest that VEGF121 and VEGF165 expression in the SAB is responsible for the development of shoulder joint contracture, especially in elevation, among type II diabetic patients with rotator cuff disease.
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PMID:Vascular endothelial growth factor 121 and 165 in the subacromial bursa are involved in shoulder joint contracture in type II diabetics with rotator cuff disease. 1455 30

Vascular endothelial growth factor (VEGF) is highly expressed in the airway of patients with asthma. Whether VEGF affects eosinophil function in vitro and if VEGF receptors are involved was tested. Eosinophils were from venous blood of healthy donors. Cell migration was studied by micropore filter assays. Signaling mechanisms required for VEGF-dependent migration were tested using signaling enzyme blockers. Expression of flt-1 and KDR/flk-1 mRNA in eosinophils was demonstrated in reverse transcriptase-polymerase chain reaction, and receptor expression was investigated by fluorescence-activated cell sorting analysis. Eosinophil cationic protein release was measured in eosinophil supernatants by enzyme-linked immunosorbent assay. VEGF significantly stimulated eosinophil chemotaxis via activation of protein kinase C and phosphatidylinositol 3'-kinase. The effect on migration was reversed by an antibody against VEGF receptor flt-1, but not by an antibody against KDR/flk-1. Expression of VEGF receptor flt-1 mRNA was shown and synthesis of VEGF receptor in eosinophils is suggested by detection of VEGF receptor immunoreactivity on the cell surface. Data suggest that VEGF receptor flt-1 is expressed by eosinophils whose activation with VEGF stimulates directed migration and release of eosinophil cationic protein. Thus, VEGF may play an important role in the modulation of eosinophilic inflammation.
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PMID:Expression and function of the vascular endothelial growth factor receptor FLT-1 in human eosinophils. 1460 15

Although information about the development of primitive and definitive hematopoiesis has been elucidated in murine embryos and embryonic stem (ES) cells, there have been few in vitro studies of these processes in primates. In this study, we investigated hematopoietic differentiation from cynomolgus monkey ES cells grown on OP9, a stromal cell line deficient in macrophage colony-stimulating factor. Primitive erythrocytes (EryP) and definitive erythrocytes (EryD) developed sequentially from ES cells in the culture system; this was confirmed by immunostaining and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of embryonic, fetal and adult globin genes. EryP were detected on day 8 without exogenous erythropoietin (EPO), whereas EryD appeared on day 16 and had an indispensable requirement for exogenous EPO. RT-PCR analysis of the cultures revealed a sequential expression of genes associated with primitive and definitive hematopoietic development that was equivalent to that seen during primate ontogeny in vivo. Vascular endothelial growth factor (VEGF) increased, in a dose-dependent manner, not only the number of floating hematopoietic cells, but also the number of adherent hematopoietic cell clusters containing CD34-positive immature progenitors. In colony assays, exogenous VEGF also had a dose-dependent stimulatory effect on the generation of primitive erythroid colonies. More efficient primitive and definitive erythropoiesis was induced by re-plating sorted CD34-positive cells. Thus, this system reproduces early hematopoietic development in vitro and can serve as a model for analyzing the mechanisms of hematopoietic development in primates.
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PMID:Development of primitive and definitive hematopoiesis from nonhuman primate embryonic stem cells in vitro. 1508 70

Vascular endothelial growth factor (VEGF)-C and VEGF-D are potent lymphangiogenic factors produced by tumour and stromal cells. The purpose of this study was to investigate the expression of VEGF-C and VEGF-D in the organ microenvironment. We implanted human KM12 colon carcinoma cell lines into the subcutis and caecal wall of nude mice. The expression of VEGF-C and VEGF-D mRNAs and proteins were examined by reverse transcriptase-polymerase chain reaction and immunohistochemistry, respectively. Under culture conditions, VEGF-C mRNA was not detected in KM12 cells; however, VEGF-C expression was detected after implantation of KM12 cells into nude mice. VEGF-C and VEGF-D protein contents were higher in orthotopic (caecal wall) tumours than in ectopic (subcutis) tumours. Small vessels expressing VEGF receptor-3 were observed in the peripheral portions of caecal tumours. In metastatic liver tumours, VEGF-C and VEGF-D proteins were produced in lower amounts than those in caecal tumours. These data suggest that the expression of lymphangiogenic factors is influenced by the organ microenvironment. Therefore, experimental studies of colon cancer lymphangiogenesis should be performed with orthotopic implantation models.
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PMID:Regulation of vascular endothelial growth factor (VEGF)-C and VEGF-D expression by the organ microenvironment in human colon carcinoma. 1519 47

Maspin is a mammary serine protease inhibitor or serpin with tumor suppressive and antiangiogenic activity that inhibits tumor motility, invasion and metastasis, at least by its actions on cell membrane and extracellular matrix (ECM) proteins. Previous studies documented that the quinazoline-derived alpha1-adrenoceptor antagonist doxazosin affects the attachment and migration of prostate cancer cells. In this study, we investigated the effect of maspin overexpression on the apoptotic/antiadhesion response of prostate cancer cells to doxazosin. The response of maspin-overexpressing clones of human prostate cancer cells DU-145 to doxazosin was evaluated by determining cell viability, apoptosis and cell proliferation on the basis of the trypan blue exclusion assay/methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay, Hoechst staining and caspase-3 activation, and [(3)H]thymidine incorporation assay. Vascular endothelial growth factor (VEGF), transforming growth factor betaRII (TGFbetaRII), Smad4 (a TGFbeta intracellular effector) and bax expression was evaluated at the mRNA and protein level using reverse transcriptase-polymerase chain reaction and Western blotting, respectively. The effect of doxazosin on cell attachment of maspin-expressing prostate cancer cells was evaluated on collagen- and fibronectin-coated plates. Cell migration was assessed using the wounding assay. In response to tumor necrosis factor-related apoptosis-inducing ligand, DU-145-maspin expressing cells undergo apoptosis, via poly(ADP-ribose) polymerasecleavage and caspase-3 activation. DU-145-maspin cells exhibited higher sensitivity to doxazosin and an earlier temporal activation of caspase-3. The number of apoptotic cells detected in response to doxazosin was significantly higher compared to the neo control (P<0.0001). Doxazosin resulted in dramatic downregulation of the 189 isoform of VEGF in maspin transfectants, while a fivefold induction of Smad4 mRNA expression was detected in those cells after 24 h of treatment. Maspin overexpression in prostate cancer cells resulted in an increased ability to attach to ECM-coated plates, and doxazosin treatment considerably antagonized this effect by decreasing the attachment potential to collagen and fibronectin. The present study supports the ability of maspin to enhance the apoptotic threshold of prostate cancer cells to the quinazoline-based alpha1-adrenoceptor antagonist doxazosin. These findings may have therapeutic significance in the development of antiangiogenic targeting by doxazosin and derivative agents for advanced prostate cancer.
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PMID:Maspin sensitizes prostate cancer cells to doxazosin-induced apoptosis. 1600 19


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