22
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found

      Phosphatidylinositide 3-Kinase Is Important in Late-Stage Fibroblast Growth Factor-1-Mediated Angiogenesis in vivo

      research-article

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          We previously reported that overexpression of a secreted version of fibroblast growth factor-1 (sp-FGF-1) has the ability to induce angiogenesis in the chicken chorioallantoic membrane (CAM). In our current study, we examine the effects of sp-FGF-1 through a time course analysis of angiogenesis in the chicken CAM on days 3, 4, and 5 after gene transfection. Significant angiogenesis was observed on days 4 and 5 after gene transfection in the CAM assay. To evaluate the role of phosphatidylinositide 3-kinase (PI3K) signaling in sp-FGF-1-induced angiogenesis, we analyzed mRNA expression levels of PI3K and protein activity through its immediate downstream target, AKT-1. We found upregulation of both PI3K and AKT mRNA expression levels in day 5 sp-FGF-1 versus day 5 vector control-transfected CAMs. Furthermore, by blocking PI3K phosphorylation using the specific inhibitor, LY294002, we found that downstream phosphorylation of AKT-1 was inhibited. More importantly, the blockade of the PI3K pathway via LY294002 in sp-FGF-1-transfected CAMs significantly inhibited angiogenesis. These results further elucidate the molecular mechanisms of the sp-FGF-1 signaling pathway and it underscores the importance of PI3K signaling in FGF-1-stimulated angiogenesis in vivo. It also provides a basis for the role of sp-FGF-1 in the development of therapeutic treatments to combat vascular insufficiencies and angiogenesis-dependent cancers.

          Related collections

          Most cited references27

          • Record: found
          • Abstract: found
          • Article: not found

          FGF and VEGF function in angiogenesis: signalling pathways, biological responses and therapeutic inhibition.

          Angiogenic growth factors such as fibroblast growth factors (FGFs) and vascular endothelial growth factors (VEGFs) are currently targets of intense efforts to inhibit deregulated blood vessel formation in diseases such as cancer. FGFs and VEGFs exert their effects via specific binding to cell surface-expressed receptors equipped with tyrosine kinase activity. Activation of the receptor kinase activity allows coupling to downstream signal transduction pathways that regulate proliferation, migration and differentiation of endothelial cells. Inhibitors of FGF and VEGF signalling are currently in clinical trials. In this article, the current knowledge of FGF- and VEGF-induced signal transduction that leads to specific biological responses will be summarized. Furthermore, the manner in which this knowledge is being exploited to regulate angiogenesis will be discussed.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Role of Akt signaling in vascular homeostasis and angiogenesis.

            Akt is a serine/threonine protein kinase that is activated by a number of growth factors and cytokines in a phosphatidylinositol-3 kinase-dependent manner. Although antiapoptotic activity of Akt is well known, it also regulates other aspects of cellular functions, including migration, glucose metabolism, and protein synthesis. In this review, Akt signaling in endothelial cells and its critical roles in the regulation of vascular homeostasis and angiogenesis will be discussed.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Phosphatidylinositol 3-kinase signaling mediates angiogenesis and expression of vascular endothelial growth factor in endothelial cells.

              Phosphatidylinositol 3-kinase (PI 3-kinase) is a signaling molecule that controls numerous cellular properties and activities. The oncogene v-p3k is a homolog of the gene coding for the catalytic subunit of PI 3-kinase, p110alpha. P3k induces transformation of cells in culture, formation of hemangiosarcomas in young chickens, and myogenic differentiation in myoblasts. Here, we describe a role of PI 3-kinase in angiogenesis. Overexpression of the v-P3k protein or of cellular PI 3-kinase equipped with a myristylation signal, Myr-P3k, can induce angiogenesis in the chorioallantoic membrane (CAM) of the chicken embryo. This process is characterized by extensive sprouting of new blood vessels and enlargement of preexisting vessels. Overexpression of the myristylated form of the PI 3-kinase target Akt, Myr-Akt, also induces angiogenesis. Overexpression of the tumor suppressor PTEN or of dominant-negative constructs of PI 3-kinase inhibits angiogenesis in the yolk sac of chicken embryos, suggesting that PI 3-kinase and Akt signaling is required for normal embryonal angiogenesis. The levels of mRNA for vascular endothelial growth factor (VEGF) are elevated in cells expressing activated PI 3-kinase or Myr-Akt. VEGF mRNA levels are also increased by insulin treatment through the PI 3-kinase-dependent pathway. VEGF mRNA levels are decreased in cells treated with the PI 3-kinase inhibitor LY294002 and restored by overexpression of v-P3k or Myr-Akt. Overexpression of VEGF by the RCAS vector induces angiogenesis in chicken embryos. These results suggest that PI 3-kinase plays an important role in angiogenesis and regulates VEGF expression.
                Bookmark

                Author and article information

                Journal
                JVR
                J Vasc Res
                10.1159/issn.1018-1172
                Journal of Vascular Research
                S. Karger AG
                1018-1172
                1423-0135
                2006
                December 2005
                21 December 2005
                : 43
                : 1
                : 61-69
                Affiliations
                aDepartment of Medical Physiology and Cardiovascular Research Institute, Texas A&M University System Health Science Center, bDepartment of Veterinary Pathobiology, College of Veterinary Medicine, and cDepartment of Poultry Sciences, Texas A&M University, College Station, Tex., and dDivision of Molecular Cardiology, Cardiovascular Research Institute, Texas A&M University System Health Science Center, College of Medicine, Temple, Tex., USA
                Article
                89492 J Vasc Res 2006;43:61–69
                10.1159/000089492
                16272825
                fde5bac5-0906-4139-966c-0ad75a4b10ab
                © 2006 S. Karger AG, Basel

                Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher. Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug. Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

                History
                : 17 December 2004
                : 25 June 2005
                Page count
                Figures: 7, References: 30, Pages: 9
                Categories
                Research Paper

                General medicine,Neurology,Cardiovascular Medicine,Internal medicine,Nephrology
                Angiogenesis,Phosphatidylinositide 3-kinase,Fibroblast growth factor-1

                Comments

                Comment on this article