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Matrigel Plug (matrigel + plug)
Selected AbstractsTriptolide functions as a potent angiogenesis inhibitorINTERNATIONAL JOURNAL OF CANCER, Issue 1 2010Ming-Fang He Abstract Triptolide is a key anti-inflammatory compound of the Chinese herbal medicine Tripterygium wilfordii Hook. f. (Celastraceae). It also possesses potent antitumor activity. In this study, we show that triptolide is an angiogenesis inhibitor based on various angiogenesis assays. The IC50 in in vitro assays was 45 nM, which was much lower than the plasma concentrations of triptolide in the rat or human administered with T. wilfordii extracts for treating inflammation. When dosed in vivo, triptolide potently inhibited angiogenesis at 100 nM in Matrigel plug assay. Triptolide at 0.75 mg/kg/day significantly blocked tumor angiogenesis and tumor progression in murine tumorigenesis assay. The underlying mechanism of triptolide correlated with downregulation of proangiogenic Tie2 and VEGFR-2 expression in human umbilical vein endothelial cell by semiquantitative RT-PCR and western blot analysis. Although Tie2 inhibition appeared to be a later event as compared with VEGFR-2, Tie2 overexpression significantly attenuated the inhibitory effect of triptolide on endothelial proliferation and network formation. By contrast, Tie2 knockdown mimicked the inhibitory effect of triptolide on endothelial network formation. Our findings suggest that antitumor action of triptolide is partly via inhibition of tumor angiogenesis by blocking 2 endothelial receptor-mediated signaling pathways, and triptolide can be a promising antiangiogenic agent. [source] Gorham-Stout Syndrome: A Monocyte-Mediated Cytokine Propelled Disease,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2006Silvia Colucci Abstract We studied the biological features and the immunophenotype of a cell culture established from the lesion of soft tissues of a woman affected by Gorham-Stout syndrome. We found that these cells belonged to a monocytic lineage with some characteristics of immature osteoclasts and were able to release large amounts of osteoclastogenic and angiogenic molecules that may contribute to disease progression. Introduction: Gorham-Stout syndrome is a rare disease characterized by osteolysis and proliferation of vascular or lymphatic vessels, with a severe outcome. Its etiology and the identification of the cell types involved are completely unknown. Materials and Methods: A cell culture from a lesion of soft tissues was established, and its behavior in vitro and in immunodeficient mice was studied. We analyzed (1) the cell phenotype by flow cytometry; (2) the adhesive and migratory properties on different substrates; (3) the ability to differentiate into mature osteoclasts; (4) the production of osteclastogenic and angiogenic molecules; (5) the in vivo angiogenic activity of the cells subcutaneously implanted in mouse in a Matrigel plug; and (6) the ability to recapitulate the disease when transplanted in nude mice. Results and Conclusions: The established culture consisted of a morphologically homogeneous cell population belonging to a monocytic lineage having some features of an osteoclast-like cell type. Cells had an invasive phenotype, were angiogenic, and produced osteoclastogenic (IL-6, TGF-,1, IL-1,) and angiogenic (vascular endothelial growth factor-A {VEGF-A}, CXCL-8) molecules when challenged with inflammatory cytokines. Immunodeficient mice injected with these cells did not show any bone lesions or vascular alteration, but had high amounts of circulating human IL-6 and VEGF-A. Cells isolated from a cutaneous lymphangiomatosis did not show any of these findings. These data suggest that cells of monocyte-macrophage lineage play an essential role in the pathogenesis of Gorham-Stout disease, whose progression is propelled by cytokine circuits that accelerate angiogenesis and osteoclastogenesis. [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] 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] Inhibition of angiogenesis by interleukin-4 gene therapy in rat adjuvant-induced arthritisARTHRITIS & RHEUMATISM, Issue 8 2006Christian S. Haas Objective Interleukin-4 (IL-4) can modulate neovascularization. In this study, we used a gene therapy approach to investigate the role of IL-4 in angiogenesis in rat adjuvant-induced arthritis (AIA), a model for rheumatoid arthritis. Methods Rats received an adenovirus producing IL-4 (AxCAIL-4), a control virus without insert, or control vehicle (phosphate buffered saline) intraarticularly before arthritis onset. At peak onset of arthritis, rats were killed. Vascularization was determined in the synovial tissue, and correlations with inflammation were assessed. Ankle homogenates were used in angiogenesis assays in vitro and in vivo, and protein levels of cytokines and growth factors were assessed by enzyme-linked immunosorbent assay. Synovial tissue expression of ,v integrins was determined by immunohistochemistry. Results IL-4 induced a reduction in synovial tissue vessel density, which was paralleled by a decrease in inflammation. AxCAIL-4 joint homogenates significantly (P < 0.05) inhibited both endothelial cell (EC) migration and tube formation in vitro. Similarly, AxCAIL-4 inhibited capillary sprouting in the rat aortic ring assay, and vessel growth in the in vivo Matrigel plug assay. The angiostatic effect occurred despite high levels of vascular endothelial growth factor (VEGF), and was associated with down-regulation of the proangiogenic cytokines IL-18, CXCL16, and CXCL5 and up-regulation of the angiogenesis inhibitor endostatin. Of interest, AxCAIL-4 also resulted in decreased EC expression of the ,v and ,3 integrin chains. Conclusion In rat AIA, IL-4 reduces synovial tissue vascularization via angiostatic effects, mediates inhibition of angiogenesis via an association with altered pro- and antiangiogenic cytokines, and may inhibit VEGF-mediated angiogenesis and exert its angiostatic role in part via ,v,3 integrin. This knowledge of the specific angiostatic effects of IL-4 may help optimize target-oriented treatment of inflammatory arthritis. [source] Antiangiogenic and Immunomodulatory Effects of Rapamycin on Islet Endothelium: Relevance for Islet TransplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 11 2006V. Cantaluppi Donor intra-islet endothelial cells contribute to neovascularization after transplantation. Several factors may interfere with this process and ultimately influence islet engraftment. Rapamycin, a central immunosuppressant in islet transplantation, is an mTOR inhibitor that has been shown to inhibit cancer angiogenesis. The aim of this study was to evaluate the effects of rapamycin on islet endothelium. Rapamycin inhibited the outgrowth of endothelial cells from freshly purified human islets and the formation of capillary-like structures in vitro and in vivo after subcutaneous injection within Matrigel plugs into SCID mice. Rapamycin decreased migration, proliferation and angiogenic properties of human and mouse islet-derived endothelial cell lines with appearance of apoptosis. The expression of angionesis-related factors VEGF, ,V,3 integrin and thrombospondin-1 on islet endothelium was altered in the presence of rapamycin. On the other hand, rapamycin decreased the surface expression of molecules involved in immune processes such as ICAM-1 and CD40 and reduced the adhesion of T cells to islet endothelium. Our results suggest that rapamycin exerts dual effects on islet endothelium inducing a simultaneous inhibition of angiogenesis and a down-regulation of receptors involved in lymphocyte adhesion and activation. [source] G-CSF-mobilized peripheral blood mononuclear cells from diabetic patients augment neovascularization in ischemic limbs but with impaired capabilityJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 5 2006B. ZHOU Summary.,Background: Autologous transplantation of mobilized peripheral blood mononuclear cells (M-PBMNCs) is a novel approach to improve critical limb ischemia (CLI) in diabetes. However, endothelial progenitor cells (EPCs) from diabetes are dysfunctional and impaired in ischemia-induced neovascularization. Objective: This study aimed to confirm the compromised efficiency of diabetic M-PBMNCs in therapeutic neovascularization, and to determine the underlying mechanisms of this impairment. Methods: Diabetic M-PBMNCs from 17 diabetic patients or healthy controls, or phosphate-buffered saline (PBS) were injected into the ischemic limbs of streptozotocin-induced diabetic nude mice. The limb blood perfusion, ambulatory score, ischemia damage, capillary/fiber ratio, arteriole density, collateral vessel formation, and pericytes recruitment were evaluated between these three groups. Non-invasive real time image and histopathology were used to detect the in vivo role of transplanted M-PBMNCs. Proliferation and adhesion of EPCs were assayed. In vitro vascular network incorporation and matrigel plug assay were used to test the pro-neovascularization role of M-PBMNCs. Results: Transplantation of diabetic M-PBMNCs also improved neovascularization, but to a lesser extent from that observed with non-diabetic ones. This was associated with the impairment of diabetic M-PBMNCs capacity to differentiate into EPCs, to incorporate into vessel-like tubules in vitro, to participate in vascular-like structure formation in a subcutaneous matrigel plug, and to stimulate the recruitment of pericytes/smooth muscle cells. In addition, there was impairment in vasculogenesis, which was related to the reduced adhesion ability of EPCs from diabetic M-PBMNCs. Conclusions: Diabetes reduced the capacity of M-PBMNCs to augment neovascularization in ischemia. [source] | ||||||||||