Thromb Haemost 2004; 92(02): 403-412
DOI: 10.1160/TH04-02-0073
Endothelium and Vascular Development
Schattauer GmbH

Histidine-Proline Rich Glycoprotein (HPRG) binds and transduces anti-angiogenic signals through cell surface tropomyosin on endothelial cells

Authors

  • Xiaojun Guan

    1   Attenuon, LLC, San Diego, California, New York, USA
  • Jose C. Juarez

    1   Attenuon, LLC, San Diego, California, New York, USA
  • Xiaoping Qi

    3   Division of Hematology-Oncology, Case Western Reserve University, School of Medicine, Cleveland, Ohio, New York, USA
  • Natalya V. Shipulina

    2   Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri, New York, USA
  • David E. Shaw

    1   Attenuon, LLC, San Diego, California, New York, USA
    4   D. E. Shaw Research and Development, LLC, New York, New York, USA
  • William T. Morgan

    2   Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri, New York, USA
  • Keith R. McCrae

    3   Division of Hematology-Oncology, Case Western Reserve University, School of Medicine, Cleveland, Ohio, New York, USA
  • Andrew P. Mazar

    1   Attenuon, LLC, San Diego, California, New York, USA
  • Fernando Doñate

    1   Attenuon, LLC, San Diego, California, New York, USA
Further Information

Publication History

Received 05 February 2004

Accepted after resubmission 06 May 2004

Publication Date:
30 November 2017 (online)

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Summary

The anti-angiogenic properties of the histidine-proline–rich (H/P) domain of HPRG have recently been described (Juarez JC, et al. Cancer Research 2002; 62: 5344-50). However, the binding site that mediates these properties is unknown. HPRG is evolutionarily, functionally and structurally related to cleaved high molecular weight kininogen (HKa), an anti-angiogenic polypeptide that stimulates apoptosis of proliferating endothelial cells through binding to cell-surface tropomyosin (Zhang J-C, et al. Proc Natl Acad Sci USA 2002; 99: 12224-9). In this study, we demonstrate that HPRG binds with high affinity to FGF-2–stimulated human umbilical vein endothelial cells (HUVEC) and immobilized tropomyosin in a Zn2+ or pH-dependent manner, and that this interaction is mediated by the H/P domain of HPRG. At least two binding sites for HPRG, tropomyosin and heparan sulfate proteoglycans (HSPs), were identified on the surface of FGF-2–activated endothelial cells. Translocation of tropomyosin to the surface of HUVEC occurred in response to FGF-2, and the anti-angiogenic activity of HPRG in a Matrigel plug model was partially inhibited by soluble tropomyosin. These results suggest that HPRG binds to endothelial cell surface tropomyosin which at least partially mediates the antiangiogenic effects of HPRG.