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MMP-2 regulates human platelet activation by interacting with integrin alphaIIbbeta3

W-S Choi1, O-H Jeon, H-H Kim

  • 1National Research Laboratory, Department of Biochemistry, College of Science, Yonsei University, Seoul, Korea. dskim@yonsei.ac.kr

Journal of Thrombosis and Haemostasis : JTH
|December 20, 2007
PubMed
Abstract

Insights

Matrix metalloproteinase-2 (MMP-2) regulates platelet activation and aggregation by binding to integrin alpha(IIb)beta(3). Blocking this interaction with MMP-2’s hemopexin-like domain inhibits platelet activation markers and aggregation.

Area of Science:

  • Biochemistry
  • Hematology
  • Molecular Biology

Background:

  • Human platelets secrete matrix metalloproteinases (MMPs) upon activation, influencing cellular processes.
  • MMP-2's role in platelet activation and aggregation is known, but its precise mechanism remains unclear.

Purpose of the Study:

  • To elucidate the biochemical mechanism of MMP-2-mediated platelet activation and aggregation.
  • To identify the specific platelet surface target of MMP-2.

Main Methods:

  • Flow cytometry and microscopy to analyze MMP-2 binding to platelets.
  • Immunoprecipitation and Western blotting to identify MMP-2's cell surface target.
  • Functional assays measuring platelet activation markers (CD62P, active alpha(IIb)beta(3)) and aggregation.

Main Results:

  • ProMMP-2 binds to integrin alpha(IIb)beta(3) on activated platelets, where it is converted to MMP-2.
  • Fibrinogen competes with MMP-2 for binding to alpha(IIb)beta(3).
  • A recombinant hemopexin-like domain of MMP-2 blocked its interaction with alpha(IIb)beta(3), reducing activation markers and platelet aggregation.

Conclusions:

  • Platelet activation and aggregation are regulated by MMP-2's specific interaction with integrin alpha(IIb)beta(3).
  • The C-terminal hemopexin-like domain of MMP-2 is crucial for binding to alpha(IIb)beta(3).

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