Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.7.1.2 (nitrate reductase)
 3,861 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The objectives of this study were to observe the effect of overexpression of vascular endothelial growth factor (VEGF) on the proliferation of the malignant melanoma (MM) cell line A375, and to study the role of nitric oxide (NO) in this process and the mechanism of VEGF induced-A375 cell proliferation. The VEGF(165) cDNA was transfected into A375 cells by electroporation. VEGF mRNA and protein in A375 cells were detected by RT-PCR and ELISA. The proliferation of A375 cells was assessed by cell counting and MTT assay. Protein expression of iNOS, eNOS and nNOS was detected by Western blotting. NO production in A375 cell supernatant was measured by the nitrate reductase method. VEGF mRNA in A375 cells was significantly increased 72 h and 96 h after transfection of VEGF(165) cDNA, as were VEGF protein, NO and iNOS levels. However, protein expression of eNOS and nNOS was not detected in either transfected or untransfected cells. Proliferation of A375 cells transfected with VEGF(165) cDNA was enhanced. The nitric oxide synthase inhibitor l-NAME could dose-dependently inhibit the proliferation of A375 cells evoked by VEGF. These results indicate that VEGF enhances the expression of iNOS in A375 cells and results in an increase in NO formation, which may be important in the process of VEGF-induced proliferation of A375 cells.
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PMID:Endogenous production of nitric oxide contributes to proliferation effect of vascular endothelial growth factor-induced malignant melanoma cell. 1630 95

This study examined the association of expression of vascular endothelial growth factor (VEGF), a promoter of angiogenesis, with endothelium dysfunction in preeclampsia. The level of VEGF protein and mRNA in the placenta and peripheral blood samples of 30 preeclampsia patients and 30 normotensive pregnant women was measured by immunohistochemistry, real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. VEGF expression in the human umbilical vein endothelial cells (HUVECs) was blocked by small interfering RNAs (siRNAs). The monolayer barrier function of HUVECs was determined by measuring the fluorescence intensity of BSA that crossed the HUVEC monolayers. The cell proliferation and cell-secreted nitric oxide (NO) level were detected by MTT method and nitrate reductase assay, respectively. The results showed that VEGF was expressed in the syncytiotrophoblasts and endothelial cells of vessels and capillaries in the placenta tissue. The serum level of VEGF in the preeclampsia patients was significantly decreased as compared with that in normal pregnant subjects, although VEGF mRNA expression in the placenta tissue of preeclampsia patients remained still high. Moreover, VEGF deficit could lead to endothelium cell dysfunction, and the administration of VEGF could protect endothelium cells from injury. It was concluded that lack of VEGF contributes to endothelium dysfunction, which may lead to the occurrence and development of preeclampsia.
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PMID:VEGF deficit is involved in endothelium dysfunction in preeclampsia. 2055 84

1. Hyperhomocysteinaemia (HHcy) is associated with endothelial dysfunction and has been recognized as a risk factor of cardiovascular disease. The present study aimed to investigate the effect of homocysteine (Hcy) on endothelial function in vivo and in vitro, and the underlying signalling pathways. 2. The HHcy animal model was established by intragastric administration with l-methionine in rats. Plasma Hcy and nitric oxide (NO) concentration were measured by fluorescence immunoassay or nitrate reductase method, respectively. Vasorelaxation in response to acetylcholine and sodium nitroprusside were carried out on aortic rings. Human umbilical vein endothelial cells (HUVEC) were treated with indicated concentrations of Hcy in the in vitro experiments. Intracellular NO level and NO concentration in culture medium were assayed. The alterations of possible signalling proteins were detected by western blot analysis. 3. l-methionine administration induced a significant increase in plasma Hcy and decrease in plasma NO. Endothelium-dependent relaxation of aortic rings in response to acetylcholine was impaired in l-methionine-administrated rats. The in vitro study showed that Hcy reduced both intracellular and culture medium NO levels. Furthermore, Hcy decreased phosphorylation of endothelial nitric oxide synthase (eNOS) at serine-1177 and phosphorylation of Akt at serine-473. Hcy-induced dephosphorylation of eNOS at Ser-1177 was partially reversed by insulin (Akt activator) and GF109203X (PKC inhibitor). Furthermore, Hcy reduced vascular endothelial growth factor (VEGF) expression in a dose-dependent manner. 4. In conclusion, Hcy impaired endothelial function through compromised VEGF/Akt/endothelial nitric oxide synthase signalling. These findings will be beneficial for further understanding the role of Hcy in cardiovascular disease.
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PMID:Homocysteine impaired endothelial function through compromised vascular endothelial growth factor/Akt/endothelial nitric oxide synthase signalling. 2069 60