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Capillary Tube Formation (capillary + tube_formation)
Selected AbstractsAntiangiogenetic Effects of 4 Varieties of Grapes,In VitroJOURNAL OF FOOD SCIENCE, Issue 6 2010Ming Liu Abstract:, The purpose of this study was to investigate the inhibitory effects of grapes on the human umbilical vein endothelial (HUVE) cells' capillary tube formation and matrix metalloproteinase-2 (MMP-2) expression secreted into the medium. Four different grape varieties (Concord, Niagara, Chardonnay, and Pinot Noir) were extracted using 80% acetone and the extracts were stored at ,80 °C. The total amount of phenolics and flavonoids for each of the 4 grape varieties were determined by spectrophotometry. Grape extracts were co-cultured with HUVE cells on Matrigel and inhibitory effects on tube formation were observed under a microscope. The inhibitory effects of grape extracts on MMP-2 expression were examined by zymogram. All 4 grape varieties inhibited the tube formation of HUVE cells in a dose-dependent manner on Matrigel. Except for Chardonnay, the other 3 grape varieties completely inhibited secretion of MMP-2 at 20 mg/mL. There was a significant positive relationship between the total phenolics and flavonoids and antiangiogenetic activities. The grapes tested have the potential to inhibit angiogenesis mainly by their phenolics and flavonoids contents, which partly contribute to their cancer chemopreventive efficacy. [source] Low-molecular-weight heparins and angiogenesis,APMIS, Issue 2 2006KLAS NORRBY The involvement of the vascular system in malignancy encompasses not only angiogenesis, but also systemic hypercoagulability and a pro-thrombotic state, and there is increasing evidence that pathways of blood coagulation and angiogenesis are reciprocally linked. In fact, cancer atients often display hypercoagulability resulting in markedly increased thromboembolism, which requires anti-coagulant treatment using heparins, for example. Clinical trials reveal that treatment with various low-molecular-weight heparins (LMWHs) improves the survival time in cancer patients receiving chemotherapy compared with those receiving unfractionated standard heparin (UFH) or no heparin treatment, as well as in cancer patients receiving LMWH as thrombosis prophylaxis during primary surgery. This anti-tumor effect of the heparins appears to be unrelated to their anti-coagulant activity, but the mechanisms involved are not fully understood. Tumor growth and spread are dependent on angiogenesis and it is noteworthy that the most potent endogenous pro- and anti-angiogenic factors are heparin-binding proteins that may be affected by systemic treatment with heparins. Heparin and other glycosaminoglycans play a role in vascular endothelial cell function, as they are able to modulate the activities of angiogenic growth factors by facilitating the interaction with their receptor and promoting receptor activation. To date, preclinical studies have demonstrated that only LMWH fragments produced by the heparinase digestion of UFH, i.e. tinzaparin, exert anti-angiogenic effects in any type of tissue in vivo. These effects are fragment-mass-specific and angiogenesis-type-specific. Data on the effect of various LMWHs and UFH on endothelial cell capillary tube formation and proliferation in vitro are also presented. We hope that this paper will stimulate and facilitate future research designed to elucidate whether the anti-angiogenic or anti-tumor effects of commercial LMWHs in their own right are agent specific and whether anti-angiogenic properties increase the anti-tumor properties of the LMWHs in the clinic. [source] Modulation of the angiogenic phenotype of normal and systemic sclerosis endothelial cells by gain,loss of function of pentraxin 3 and matrix metalloproteinase 12ARTHRITIS & RHEUMATISM, Issue 8 2010Francesca Margheri Objective Studies have shown that in systemic sclerosis (SSc) endothelial cells, overproduction of matrix metalloproteinase 12 (MMP-12) and pentraxin 3 (PTX3) is associated with defective angiogenesis. This study was undertaken to examine whether overexpression of the relevant molecules could inhibit angiogenesis of normal microvascular endothelial cells (MVECs), and whether silencing of these molecules in SSc MVECs could restore the lost angiogenic properties of the cells in vitro and in vivo. Methods Transient transfection of MVECs with human MMP12 and PTX3 was performed by electroporation. Silencing of MMP12 and PTX3 was obtained by treatment with small interfering RNA, and treatment effects were validated by Western blotting with specific antibodies and a fluorimetric assay. In vitro cell migration and capillary morphogenesis were studied on Matrigel substrates. In vivo angiogenesis was studied using a Matrigel sponge assay in mice. Results Transfection of MMP12 and PTX3 in normal MVECs resulted in loss of proliferation, invasion, and capillary morphogenesis in vitro, attributed to truncation of the urokinase-type plasminogen activator receptor by MMP12 and to the anti,fibroblast growth factor 2/anti,vascular endothelial growth factor activity of PTX3. These effects were particularly evident in mixed populations of transfected normal MVECs (50% transfected with MMP12 and 50% with PTX3). Silencing of the same molecules in SSc MVECs increased their invasion in Matrigel. Single-gene silencing did not increase the capillary morphogenesis of SSc MVECs, whereas double-gene,silenced cells showed a burst of capillary tube formation. Culture medium of silenced SSc MVECs stimulated angiogenesis in assays of Matrigel sponge invasion in mice. Conclusion Overexpression of either MMP12 or PTX3 in normal MVECs blunts their angiogenic properties. Loss of function of MMP12 and PTX3 in SSc MVECs restores the ability of the cells to produce capillaries in vitro and induces vascularization in vivo on a Matrigel sponge. [source] Anti,neuropilin-1 peptide inhibition of synoviocyte survival, angiogenesis, and experimental arthritisARTHRITIS & RHEUMATISM, Issue 1 2010Jin-Sun Kong Objective To delineate the role of neuropilin-1 (NP-1), a vascular endothelial growth factor receptor (VEGFR), in rheumatoid inflammation and to determine whether blockade of NP-1 could suppress synoviocyte survival and angiogenesis. Methods VEGF111,165 peptide, which encompasses the NP-1 binding domain of VEGF165, was generated by cleaving VEGF165 with plasmin. The effect of this peptide on the interaction between VEGF165 and its receptor was determined by 125I-VEGFR binding assay. Assays to determine synoviocyte apoptosis, adhesion, and migration were performed in the presence of VEGF165 and/or the peptide. VEGF165 -induced angiogenesis was assessed by measuring the proliferation, tube formation, and wounding migration of endothelial cells (ECs). Mice were immunized with type II collagen to induce experimental arthritis. Results VEGF111,165 peptide specifically inhibited the binding of 125I-VEGF165 to NP-1 on rheumatoid synoviocytes and ECs. The peptide eliminated the VEGF165 -mediated increase in synoviocyte survival and activation of p-ERK and Bcl-2. The peptide also completely inhibited a VEGF165 -induced increase in synoviocyte adhesion and migration. In addition, the anti,NP-1 peptide blocked VEGF165 -stimulated proliferation, capillary tube formation, and wounding migration of ECs in vitro. VEGF165 -induced neovascularization in a Matrigel plug in mice was also blocked by treatment with the peptide. Finally, subcutaneous injection of anti,NP-1 peptide suppressed arthritis severity and autoantibody formation in mice with experimental arthritis and inhibited synoviocyte hyperplasia and angiogenesis in arthritic joints. Conclusion Anti,NP-1 peptide suppressed VEGF165 -induced increases in synoviocyte survival and angiogenesis, and thereby blocked experimental arthritis. Our findings suggest that anti,NP-1 peptide could be useful in alleviating chronic arthritis. [source] 19 Cytosolic phospholipase A2 increases proliferation, inhibits apoptosis and facilitates angiogenesis in prostate cancer: a potential new therapeutic targetBJU INTERNATIONAL, Issue 2006M.I. PATEL The end-products from the arachadonic acid (AA) pathway have been shown to be tumourigenic in prostate cancer (CaP). Cytosolic phospholipase A2 (cPLA2) is the enzyme that liberates AA from plasma membranes and feeds it to the cycloxygenase and lipoxygenase pathways. In this study we aim to determine the importance of cPLA2 in prostate cancer by examining human prostate cancer specimens and in vitro cell line models. Immunohistochemistry of human prostate specimens revealed that activated cPLA2 levels were significantly higher in prostate cancer compared to benign glands.. Next to determine if inhibition of cPLA2 would lead to decreases in prostate cancer growth, we treated three CaPcell lines (PC3, DU145 and LNCaP) with pyrrolidine 2 (P2), a specific cPLA2 inhibitor and showed it significantly inhibited the growth of all three cell lines at concentrations between 1,10,M by MTS assay. P2 treatment induced a cell cycle block at G0/G1 and a corresponding reduction in BrdU incoprporation by flow cytometry and 3H-Thymidine incorporation. In addition cPLA2 knock by siRNA also showed a similar inhibition in proliferation, confirming the importance of cPLA2 in CaP proliferation. P2 also induced apoptosis in CaP cell lines by Caspase 3/7 assay. Treatment of Endothelial cell (HUVECs) cells with P2 had a very significant inhibitory effect on capillary tube formation in matrigel. We conclude that cytosolic phospholipase A2 is overactive in human prostate cancer. It leads to CaP proliferation as well as apoptosis. cPLA2 also is required in endothelial angiogenesis. Inhitibion of cPLA2 by P2 will reduce cancer growth, induce apoptosis and inhibit angiogeneisis in an in vitro model. Together, these findings suggest that cPLA2 could be a potential target in CaP treatment and warrants further validation in animal and human trials. [source] Morphological and biochemical effects of immunosuppressive drugs in a capillary tube assay for endothelial dysfunctionCLINICAL TRANSPLANTATION, Issue 2003Chumpon Wilasrusmee Abstract: Immunosuppressive drugs common in clinical transplantation are known to have untoward effects on the vascular system. The effects of some drugs, notably cyclosporin A (CyA), have been studied on the vascular system, while those of others have not. In the vascular system, endothelial cells are the predominant cell type exposed to intravascular concentrations of immunosuppressive drugs. We therefore studied the effects of drugs common in clinical transplantation on endothelial cells in a capillary tube assay. The endothelial cells in the capillary tubes are morphologically more similar to those in the microvasculature than endothelial cells in monolayers. We studied the kinetics and extent of capillary tube formation and prostacyclin (PGI2) and endothelin-1 (ET-1) release from the in vitro capillaries to determine the morphological and biochemical effects of five immunosuppressive agents on endothelial function. We found a significant difference in the morphological and biochemical effects of the two common calcineurin inhibitors, CyA and tacrolimus (FK506) on capillary morphology in vitro. The former had a pronounced injurious effect on the morphology of the in vitro capillaries, while the latter did not. CyA also significantly increased ET-1 release by the capillaries, but FK506 did not. Mycophenolate mofetil (MMF) was the only other agent that had a moderately injurious effect on the morphology of the in vitro capillaries. Sirolimus (rapamycin) and dexamethasone, similar to FK506, had no effect on the capillary morphology. All these agents, except dexamethasone, increased PGI2 release. Our data suggest that CyA adversely affects the morphology of the microvasculature and that this is mediated, at least partly, by an increased ET-1 release by endothelial cells exposed to CyA. These findings describe a novel effect of CyA and MMF on endothelial cells that could be relevant to understanding the mechanisms of immunosuppressive drug-mediated endothelial injury in clinical transplantation. [source] | ||||||||||