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Antiangiogenic Factors (antiangiogenic + factor)
Selected AbstractsPigment epithelium-derived factor binds to cell-surface F1 -ATP synthaseFEBS JOURNAL, Issue 9 2010Luigi Notari Pigment epithelium-derived factor (PEDF), a potent blocker of angiogenesis in vivo, and of endothelial cell migration and tubule formation, binds with high affinity to an as yet unknown protein on the surfaces of endothelial cells. Given that protein fingerprinting suggested a match of a , 60 kDa PEDF-binding protein in bovine retina with Bos taurus F1 -ATP synthase ,-subunit, and that F1Fo -ATP synthase components have been identified recently as cell-surface receptors, we examined the direct binding of PEDF to F1. Size-exclusion ultrafiltration assays showed that recombinant human PEDF formed a complex with recombinant yeast F1. Real-time binding as determined by surface plasmon resonance demonstrated that yeast F1 interacted specifically and reversibly with human PEDF. Kinetic evaluations revealed high binding affinity for PEDF, in agreement with PEDF affinities for endothelial cell surfaces. PEDF blocked interactions between F1 and angiostatin, another antiangiogenic factor, suggesting overlapping PEDF-binding and angiostatin-binding sites on F1. Surfaces of endothelial cells exhibited affinity for PEDF-binding proteins of , 60 kDa. Antibodies to F1,-subunit specifically captured PEDF-binding components in endothelial plasma membranes. The extracellular ATP synthesis activity of endothelial cells was examined in the presence of PEDF. PEDF significantly reduced the amount of extracellular ATP produced by endothelial cells, in agreement with direct interactions between cell-surface ATP synthase and PEDF. In addition to demonstrating that PEDF binds to cell-surface F1, these results show that PEDF is a ligand for endothelial cell-surface F1Fo -ATP synthase. They suggest that PEDF-mediated inhibition of ATP synthase may form part of the biochemical mechanisms by which PEDF exerts its antiangiogenic activity. Structured digital abstract ,,MINT-7711286: angiostatin (uniprotkb:P00747) physically interacts (MI:0915) with F-ATPase alpha subunit (uniprotkb:P07251), F-ATPase beta subunit (uniprotkb:P00830), F-ATPase gamma subunit (uniprotkb:P38077), F-ATPase delta subunit (uniprotkb:Q12165) and F-ATPase epsilon subunit (uniprotkb:P21306) by competition binding (MI:0405) ,,MINT-7711113: angiostatin (uniprotkb:P00747) physically interacts (MI:0915) with F-ATPase epsilon subunit (uniprotkb:P21306), F-ATPase delta subunit (uniprotkb:Q12165), F-ATPase gamma subunit (uniprotkb:P38077), F-ATPase beta subunit(uniprotkb:P00830) and F-ATPase alpha subunit (uniprotkb:P07251) by surface plasmon resonance (MI:0107) ,,MINT-7711060: F-ATPase gamma subunit (uniprotkb:P38077), F-ATPase beta subunit (uniprotkb:P00830), F-ATPase alpha subunit (uniprotkb:P07251) and PEDF (uniprotkb:P36955) physically interact (MI:0915) by molecular sieving (MI:0071) ,,MINT-7711313: F-ATPase epsilon subunit (uniprotkb:P21306), F-ATPase delta subunit (uniprotkb:Q12165), PEDF (uniprotkb:P36955), F-ATPase alpha subunit (uniprotkb:P07251), F-ATPase beta subunit (uniprotkb:P00830) and F-ATPase gamma subunit(uniprotkb:P38077) physically interact (MI:0915) by molecular sieving (MI:0071) ,,MINT-7711083: PEDF (uniprotkb:P36955) physically interacts (MI:0915) with F-ATPase epsilon subunit (uniprotkb:P21306), F-ATPase delta subunit (uniprotkb:Q12165), F-ATPase gamma subunit (uniprotkb:P38077), F-ATPase beta subunit (uniprotkb:P00830) and F-ATPase alpha subunit (uniprotkb:P07251) by surface plasmon resonance (MI:0107) [source] In vivo inhibition of angiogenesis by interleukin-13 gene therapy in a rat model of rheumatoid arthritisARTHRITIS & RHEUMATISM, Issue 8 2007Christian S. Haas Objective Interleukin-13 (IL-13) is a pleiotropic cytokine that can affect vessel formation, an important component of the rheumatoid arthritis (RA) synovial tissue pannus. The purpose of this study was to use a gene therapy approach to investigate the role of IL-13 in angiogenesis in vivo, using a rat adjuvant-induced arthritis model of RA. Methods Ankle joints of female rats were injected preventatively with an adenovirus vector containing human IL-13 (AxCAIL-13), a control vector with no insert (AxCANI), or phosphate buffered saline (PBS). Joints were harvested at the peak of arthritis, and histologic and biochemical features were evaluated. Results AxCAIL-13,treated joint homogenates had lower hemoglobin levels, suggesting reduced joint vascularity, and both endothelial cell migration and tube formation were significantly inhibited (P < 0.05). Similarly, AxCAIL-13 inhibited capillary sprouting in the rat aortic ring assay and vessel growth in the Matrigel plug in vivo assay. IL-13 gene delivery resulted in up-regulation and association of phosphorylated ERK-1/2 and protein kinase C,/,II, suggesting a novel pathway in IL-13,mediated angiostasis. The angiostatic effect of AxCAIL-13 was associated with down-regulation of proangiogenic cytokines (IL-18, cytokine-induced neutrophil chemoattractant 1/CXCL1, lipopolysaccharide-induced CXC chemokine/CXCL5) and up-regulation of the angiogenesis inhibitor endostatin. The expression and activity of matrix metalloproteinases 2 and 9, which participate in angiogenesis, was impaired in response to IL-13 as compared with AxCANI and PBS treatment. Conclusion Our findings support a role for IL-13 as an in vivo antiangiogenic factor and provide a rationale for its use in RA to control pathologic neovascularization. [source] Antiangiogenic drugs: Current knowledge and new approaches to cancer therapyJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 10 2008Jose L. Mauriz Abstract Angiogenesis,process of new blood-vessel growth from existing vasculature,is an integral part of both normal developmental processes and numerous pathologies such as cancer, ischemic diseases and chronic inflammation. Angiogenesis plays a crucial role facilitating tumour growth and the metastatic process, and it is the result of a dynamic balance between proangiogenic and antiangiogenic factors. The potential to block tumour growth and metastases by angiogenesis inhibition represents an intriguing approach to the cancer treatment. Angiogenesis continues to be a topic of major scientific interest; and there are currently more antiangiogenic drugs in cancer clinical trials than those that fit into any other mechanistic category. Based on preclinical studies, researchers believe that targeting the blood vessels which support tumour growth could help treatment of a broad range of cancers. Angiogenic factors or their receptors, endothelial cell proliferation, matrix metalloproteinases or endothelial cell adhesion, are the main targets of an increasing number of clinical trials approved to test the tolerance and therapeutic efficacy of antiangiogenic agents. Unfortunately, contrary to initial expectations, it has been described that antiangiogenic treatment can cause different toxicities in cancer patients. The purpose of this article is to provide an overview of current attempts to inhibit tumour angiogenesis for cancer therapy. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:4129,4154, 2008 [source] Increased concentrations of antiangiogenic factors in mirror syndrome complicating twin-to-twin transfusion syndromePRENATAL DIAGNOSIS, Issue 4 2010Dr Federico Prefumo No abstract is available for this article. [source] The relationship of the level of circulating antiangiogenic factors to the clinical manifestations of preeclampsiaPRENATAL DIAGNOSIS, Issue 5 2009Young Nam Kim Abstract Objective This study investigated whether the antiangiogenic factors' concentrations differ according to the clinical manifestations of preeclampsia. Methods This study included 62 preeclampsia and compared the soluble fms-like tyrosine kinase-1 (sFlt-1), soluble endoglin (sEng), and placental growth factor (PlGF) concentrations among patients with different clinical manifestations of preeclampsia. We also compared the patients with preeclampsia to 62 controls matched by age, gestational age, and parity after 20 weeks of gestation. Results The sEng concentrations were significantly elevated in early-onset than in late-onset preeclampsia (105.4 ± 37.9 vs 66.3 ± 36.0 ng/mL, p = 0.0008). Moreover, the sEng levels were also higher in severe preeclampsia compared to mild (42.5 ± 31.0 vs 79.2 ± 38.6 ng/mL, p = 0.0013) and in the small for gestational age (SGA) group compared to the group without SGA (68.3 ± 39.3 vs 85.7 ± 38.2 ng/mL, p = 0.0273). The sFlt-1 levels, however, did not reveal significant difference according to the onset-time, severity, and presence of SGA. The antiangiogenic factors' concentrations were not related with the degree of hypertension or proteinuria. Conclusion Altered antiangiogenic factors might be involved in the pathogenesis of preeclampsia with synergistic, but different roles. Especially, sEng may be more related with early and severe preeclampsia. Copyright © 2009 John Wiley & Sons, Ltd. [source] Mapping pro- and antiangiogenic factors on the surface of prostasomes of normal and malignant cell originTHE PROSTATE, Issue 8 2010Adil A. Babiker Abstract BACKGROUND Angiogenesis is the formation of new blood vessels by capillary sprouting from pre-existing vessels. Tumor growth is angiogenesis-dependent and the formation of new blood vessels is associated with the increased expression of angiogenic factors. Prostasomes are secretory granules produced, stored and released by the glandular epithelial cells of the prostate. We investigated the expression of selected angiogenic and anti-angiogenic factors on the surface of prostasomes of different origins as well as the direct effect of prostasomes on angiogenesis. METHODS VEGF, endothelin-1, endostatin, and thrombospondin-1 were determined on prostasomes from seminal fluid and human prostate cancer cell lines (DU145,PC-3,LNCaP) using different immunochemical techniques. Human dermal microvascular endothelial cells were incubated with seminal and DU145 cell-prostasomes and with radioactive thymidine. The effect of prostasomes on angiogenesis was judged by measuring the uptake of labeled thymidine. The presence of any deleterious effects of prostasomes on the endothelial cells was investigated using thymidine assay and confocal laser microscopy. RESULTS VEGF and endothelin-1 were determined on malignant cell-prostasomes (no difference between cell lines) but not determined on seminal prostasomes. The same applies for the expression of endostatin but with much higher expression on malignant cell-prostasomes with obvious differences between them. Seminal and DU145 cell-prostasomes were found to have anti-angiogenic effect which was more expressed by DU145 cell-prostasomes. No deleterious effect of prostasomes on endothelial function was detected using either thymidine assay or microscopy. CONCLUSIONS Prostasomes contain pro- and anti-angiogenic factors that function to counteract each other unless the impact from one side exceeds the other to bring about dysequilibrium. Prostate 70: 834,847, 2010. © 2010 Wiley-Liss, Inc. [source] Antiangiogenic plasma activity in patients with systemic sclerosisARTHRITIS & RHEUMATISM, Issue 10 2007Mary Jo Mulligan-Kehoe Objective Systemic sclerosis (SSc; scleroderma) is a systemic connective tissue disease with an extensive vascular component that includes aberrant microvasculature and impaired wound healing. The aim of this study was to investigate the presence of antiangiogenic factors in patients with SSc. Methods Plasma samples were obtained from 30 patients with SSc and from 10 control patients without SSc. The samples were analyzed for the ability of plasma to affect endothelial cell migration and vascular structure formation and for the presence of antiangiogenic activity. Results Exposure of normal human microvascular dermal endothelial cells to plasma from patients with SSc resulted in decreased cell migration (mean ± SEM 52 ± 5%) and tube formation (34 ± 6%) compared with that in plasma from control patients (P < 0.001 for both). SSc plasma contained 2.9-fold more plasminogen kringle 1,3 fragments (angiostatin) than that in control plasma. The addition of angiostatin to control plasma resulted in inhibition of endothelial cell migration and proliferation similar to that observed in SSc plasma. In vitro studies demonstrated that granzyme B and other proteases contained in T cell granule content cleave plasminogen and plasmin into angiostatin fragments. Conclusion Plasminogen conformation in patients with SSc enables granzyme B and granule content protease to limit the proangiogenic effects of plasmin and increase the levels of antiangiogenic angiostatin. This increase in angiostatin production may account for some of the vascular defects observed in patients with SSc. [source] The role of HIF-1 alfa in apoptosis and proliferative retinopathyACTA OPHTHALMOLOGICA, Issue 2009R FERNANDES Purpose In diabetic retinal capillaries, the earlier morphological changes include pericyte loss and acellular capillary formation. These processes are regulated by interactions among a number of pro- and antiangiogenic factors, including vascular endothelial growth factor (VEGF) and Angiopoietin-2 (Ang-2). We hypothesize that increased levels of methylglyoxal (MGO) in RPE cells disrupts the balance of VEGF/Ang-2 promoting endothelial cell death and vessel regression. Methods Rats with moderate T2D, and retinal cell lines of epithelium (RPE) and endothelium (EC) were used. MGO levels were determined by HPLC. Immunohistochemical analysis was performed in retinas stained for VEGF and Ang-2. RPE cells were incubated with MGO in hypoxic conditions and the level of VEGF and Ang-2 was assessed by ELISA. EC were subsequently treated with the pre-conditioned media of the RPE cells. Cell death was determined by WB against Bax and Bcl-2, while EC proliferation was assessed by BrdU-incorporation and fibrin gel angiogenic assays. Results Hyperglycemia increases the levels of MGO in retinas and RPE cells. MGO increases the levels of Ang-2 and strongly decreases the levels of VEGF in response to hypoxia. VEGF downregulation appears to result both from increased HIF-1, degradation and low HIF-1 transcriptional activity. The MGO-induced imbalance in the VEGF/Ang-2 significantly increases the expression of Bax and decreases the levels of Bcl-2. Consistently, this imbalance leads to decreased proliferation of the EC. Conclusion In diabetic retinopathy, accumulation of MGO may play a role in VEGF/Ang-2 imbalance, triggering the activation of the apoptotic cascade which induces decreased proliferation of retinal endothelial cells and as a consequence vessels regression [source] | |||||||||||||