title: A complementary role for tetraspanin superfamily member CD151 and ADP purinergic P2Y12 receptor in platelets.
abstract: P2Y12 receptor is required for sustained activation of integrin αIIbβ3, irreversible platelet aggregation and thrombus stabilisation. Tetraspanin superfamily member CD151 associates with integrin αIIbβ3 and plays critical roles in regulation of thrombus growth and stability in vivo. The possible functional relationship between P2Y12 and CD151 in a molecular cluster in platelets may affect thrombus formation. Hence our aim was to investigate the physical and functional requirements for this association in platelets. Our investigations reveal a specific and constitutive association between CD151 and P2Y12 receptor in human platelets shown by immunoprecipitation/western blot studies and by flow cytometry. Specifically, the prominent association involves CD151 with P2Y12 oligomers, and to a lesser extent P2Y12 monomers. This association is not altered by platelet aggregation induced by different agonists. There is also a distinct complex of tetraspanin CD151 with ADP purinergic receptor P2Y12 but not P2Y1. P2Y12 oligomer interaction with CD151 is selective as compared to other tetraspanins. To investigate the functional relationship between these receptors in platelets we used wild-type or CD151 knockout (KO) mice treated with either PBS or 50 mg/kg clopidogrel. CD151 KO mice treated with clopidogrel exhibited synergy in delayed kinetics of clot retraction, in PAR-4 and collagen-mediated platelet aggregation, platelet spreading on fibrinogen and without restricting cAMP inhibition. Clopidogrel treated CD151 KO arterioles showed smaller and less stable thrombi with increased tendency to embolise ex vivo and in vivo. These studies demonstrate a complementary role between CD151 and P2Y12 receptor in platelets in regulating thrombus growth and stability.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Makkawi
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Moheimani
authors.forename: Raed
authors.initials: R
authors.lastname: Alserihi
authors.forename: David
authors.initials: D
authors.lastname: Howells
authors.forename: Mark
authors.initials: M
authors.lastname: Wright
authors.forename: Leonie
authors.initials: L
authors.lastname: Ashman
authors.affiliation: Prof. Denise E. Jackson, BAppSc (MLS), FAIMS, PhD, FFSc, Discipline Head and Program Leader of Laboratory Medicine, Head of Thrombosis and Vascular Diseases Laboratory, School of Medical Sciences, RMIT University, PO Box 71, Bundoora. Victoria 3083, Australia, Tel.: +61 3 9925 7392, Fax: +61 3 9925 7063, E-mail: denise.jackson@rmit.edu.au.
authors.forename: Denise E
authors.initials: DE
authors.lastname: Jackson
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D000077144:Clopidogrel; D003018:Clot Retraction / Q000187:drug effects; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010974:Platelet Aggregation / Q000187:drug effects / Q000235:genetics; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects / Q000235:genetics; D058925:Receptors, Purinergic P2Y12 / Q000378:metabolism*; D060185:Tetraspanin 24 / Q000235:genetics / Q000378:metabolism*; D059470:Tetraspanins / Q000235:genetics / Q000378:metabolism*; D013927:Thrombosis / Q000503:physiopathology*; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives
chemical_list: C548577:P2ry12 protein, mouse; D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D058925:Receptors, Purinergic P2Y12; D060185:Tetraspanin 24; D059470:Tetraspanins; D000077144:Clopidogrel; D013988:Ticlopidine
keywords: CD151; Platelets; clopidogrel; mice; purinergic P2Y12