Thromb Haemost 2004; 92(06): 1368-1376
DOI: 10.1160/TH04-02-0090
Platelets and Blood Cells
Schattauer GmbH

α-Adrenergic-mediated activation of human reconstituted fibrinogen receptor (integrin αIIbβ3) in Chinese hamster ovary cells

Nora Butta
1   Department of Physiopathology and Human Molecular Genetics
2   Centro de Investigaciones Biológicas (CSIC), Madrid, Spain
,
Susana Larrucea
1   Department of Physiopathology and Human Molecular Genetics
2   Centro de Investigaciones Biológicas (CSIC), Madrid, Spain
,
Consuelo Gonzalez-Manchon
1   Department of Physiopathology and Human Molecular Genetics
2   Centro de Investigaciones Biológicas (CSIC), Madrid, Spain
,
Sonia Alonso
1   Department of Physiopathology and Human Molecular Genetics
2   Centro de Investigaciones Biológicas (CSIC), Madrid, Spain
,
Roberto Parrilla
1   Department of Physiopathology and Human Molecular Genetics
2   Centro de Investigaciones Biológicas (CSIC), Madrid, Spain
› Author Affiliations

Financial support: This work has been supported in part by grants from the Direccion General de Investigacion (SAF 2000-0127, BMC2002-01053 and BMC2003-01409), Fondo de Investigaciones Sanitarias (FIS-PI021263) and Comunidad de Madrid (08.4/0029.1/2003). Nora Butta is recipient of a tenure track grant Ramon y Cajal from the Spanish Ministry of Science. Susana Larrucea was supported by a postdoctoral fellowships from the Comunidad de Madrid (08.4/0015.1/2001) and Sonia Alonso by a predoctoral fellowship from the Gobierno Vasco (BF101-40).
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Publication History

Received 12 February 2004

Accepted after revision 22 September 2004

Publication Date:
04 December 2017 (online)

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Summary

This work reports the functional studies of CHO cells coexpressing α-adrenergic (αAR) and human fibrinogen (Fg) receptors (integrin αIIbβ3). Stimulation of these cells with α-agonists produced a transient rise in the free cytosolic calcium (Ca++) accompanied by enhanced binding to soluble Fg, and these effects were prevented by specific αAR antagonists. The αadrenergic-induced activation of αIIbβ3 in CHO-αIIbβ3-αAR increased the rate of adhesion and extension of cells onto Fg coated plates, and also induced a soluble Fgand αIIbβ3-dependent formation of cell aggregates, whereas no effects were observed by the stimulation of CHO-αIIbβ3 cells. α-Adrenergic antagonists, the ligand mimetic peptide RGDS, pertussis toxin (PTX), or EDTA, they all prevented the α-adrenergic stimulation of adhesion and aggregation. However, inhibition of PKC prevented the α-adrenergic stimulation of cell adherence, whereas blocking the intracellular Ca++ mobilization impeded the stimulation of cell aggregation. The α-adrenergic activation was associated with phosphorylation of a protein of ∼100 kDa and proteins of the MAPK family. The former was selectively phosphorylated by α-adrenergic stimulation whereas the latter were phosphorylated by the binding of cells to Fg and markedly intensified by α-adrenergic stimulation.