These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Bidirectional integrin alphaIIbbeta3 signalling regulating platelet adhesion under flow: contribution of protein kinase C.
    Author: Giuliano S, Nesbitt WS, Rooney M, Jackson SP.
    Journal: Biochem J; 2003 May 15; 372(Pt 1):163-72. PubMed ID: 12585966.
    Abstract:
    Platelet adhesion on von Willebrand factor (vWf) requires the co-ordinated adhesive function of glycoprotein Ib/V/IX and integrin alphaIIbbeta3. Recent evidence [Nesbitt, Kulkarni, Giuliano, Gonclaves, Dopheide, Yap, Harper, Salem and Jackson (2002) J. Biol. Chem. 277, 2965-2972] suggests that outside-in signals from both receptors play important roles in regulating platelet-adhesion dynamics under flow. In the present study, we have examined the mechanisms utilized by protein kinase C (PKC) to promote irreversible platelet adhesion on vWf. We demonstrate that PKC is primarily activated downstream of integrin alphaIIbbeta3, not glycoprotein Ib, during platelet adhesion on vWf. This integrin alphaIIbbeta3-dependent PKC activation establishes a positive-feedback loop that promotes further integrin alphaIIbbeta3 activation, calcium mobilization and firm platelet adhesion. This feedback loop appears to be most relevant at relatively low cytosolic calcium concentrations (mean Delta[Ca(2+)](i);100 nM) as artificially elevating calcium (mean Delta[Ca(2+)](i) > 500 nM) induces integrin alphaIIbbeta3 activation and irreversible platelet adhesion independent of PKC. Our studies demonstrate the existence of a complex signalling relationship operating between PKC, cytosolic calcium and integrin alphaIIbbeta3 that serves to regulate platelet-adhesion dynamics under flow. Furthermore, we have established the existence of PKC-dependent and -independent pathways regulating integrin alphaIIbbeta3 activation and stable platelet adhesion on vWf.
    [Abstract] [Full Text] [Related] [New Search]