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Endothelial-monocyte activating polypeptide II alters fibronectin based endothelial cell adhesion and matrix assembly

Margaret A Schwarz1, Hiahua Zheng, Jie Liu

  • 1Department of Surgery, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, 125 Paterson Street, CAB 7319, New Brunswick, NJ 08903, USA. m.schwarz@umdnj.edu

Experimental Cell Research
|October 27, 2005
PubMed

Insights

Mature Endothelial-Monocyte Activating Polypeptide II (mEMAP II) inhibits endothelial cell adhesion and spreading by targeting alpha5 beta1 integrin. This mechanism underlies mEMAP II's anti-angiogenic and potential anti-tumor effects.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biochemistry

Background:

  • Mature Endothelial-Monocyte Activating Polypeptide II (mEMAP II) is a known anti-angiogenic peptide with poorly understood mechanisms.
  • mEMAP II selectively induces apoptosis in migrating and proliferating endothelial cells (EC).
  • Angiogenic processes heavily rely on EC adhesion and migration.

Purpose of the Study:

  • To elucidate the mechanism of action for mEMAP II's anti-angiogenic properties.
  • To investigate the role of cell adhesion molecules in mEMAP II's targeted effects.
  • To identify specific molecular targets of mEMAP II in endothelial cells.

Main Methods:

  • Assessed mEMAP II's effect on fibronectin (FN)-dependent microvascular EC (MEC) adhesion and spreading.
  • Utilized immunofluorescence to analyze interactions between FN, alpha5 beta1 integrin, and cellular structures.
  • Investigated the role of the alpha5 beta1 integrin in mediating mEMAP II's cellular effects.

Main Results:

  • mEMAP II significantly inhibited FN-dependent MEC adhesion and spreading.
  • The inhibitory effect of mEMAP II was dependent on the alpha5 beta1 integrin.
  • mEMAP II treatment led to the disassembly of actin stress fibers and the FN matrix.
  • mEMAP II directly blocked FN-alpha5 beta1 integrin interactions.

Conclusions:

  • mEMAP II inhibits MEC adhesion and spreading on fibronectin through direct interaction with the alpha5 beta1 integrin.
  • The alpha5 beta1 integrin is implicated as a key mediator of mEMAP II's anti-angiogenic function.
  • Understanding this mechanism provides insight into mEMAP II's anti-tumor potential.

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