Platelet CD40L Modulates Thrombus Growth Via Phosphatidylinositol 3-Kinase β, and Not Via CD40 and IκB Kinase α

Marijke J E Kuijpers; Nadine J A Mattheij; Lina Cipolla; Johanna P van Geffen; Toby Lawrence; Marjo M P C Donners; Louis Boon; Dirk Lievens; Mauro Torti; Heidi Noels; Norbert Gerdes; Judith M E M Cosemans; Esther Lutgens; Johan W M Heemskerk

doi:10.1161/ATVBAHA.114.305127

Platelet CD40L Modulates Thrombus Growth Via Phosphatidylinositol 3-Kinase β, and Not Via CD40 and IκB Kinase α

Arterioscler Thromb Vasc Biol. 2015 Jun;35(6):1374-81. doi: 10.1161/ATVBAHA.114.305127. Epub 2015 Apr 23.

Affiliations

¹ From the Departments of Biochemistry (M.J.E.K., N.J.A.M., L.C., J.P.v.G., J.M.E.M.C., J.W.M.H.) and Molecular Genetics (M.M.P.C.D.), CARIM, Maastricht University, Maastricht, The Netherlands; Division of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy (L.C., M.T.); Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université, Marseille, France (T.L.); Bioceros, Utrecht, The Netherlands (L.B.); Institute for Cardiovascular Prevention, Ludwig-Maximilians-University, Munich, Germany (D.L., N.G., E.L.); Institute for Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, Aachen, Germany (H.N.); and Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (E.L.). Marijke.Kuijpers@maastrichtuniversity.nl.
² From the Departments of Biochemistry (M.J.E.K., N.J.A.M., L.C., J.P.v.G., J.M.E.M.C., J.W.M.H.) and Molecular Genetics (M.M.P.C.D.), CARIM, Maastricht University, Maastricht, The Netherlands; Division of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy (L.C., M.T.); Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université, Marseille, France (T.L.); Bioceros, Utrecht, The Netherlands (L.B.); Institute for Cardiovascular Prevention, Ludwig-Maximilians-University, Munich, Germany (D.L., N.G., E.L.); Institute for Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, Aachen, Germany (H.N.); and Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (E.L.).

PMID: 25908768
DOI: 10.1161/ATVBAHA.114.305127

Abstract

Objective: To investigate the roles and signaling pathways of CD40L and CD40 in platelet-platelet interactions and thrombus formation under conditions relevant for atherothrombosis.

Approach and results: Platelets from mice prone to atherosclerosis lacking CD40L (Cd40lg(-/-)Apoe(-/-)) showed diminished αIIbβ3 activation and α-granule secretion in response to glycoprotein VI stimulation, whereas these responses of CD40-deficient platelets (Cd40(-/-)Apoe(-/-)) were not decreased. Using blood from Cd40lg(-/-)Apoe(-/-) and Cd40(-/-)Apoe(-/-) mice, the glycoprotein VI-dependent formation of dense thrombi was impaired on atherosclerotic plaque material or on collagen, in comparison with Apoe(-/-) blood. In all genotypes, addition of CD40L to the blood enhanced the growth of dense thrombi on plaques and collagen. Similarly, CD40L enhanced glycoprotein VI-induced platelet aggregation, even with platelets deficient in CD40. This potentiation was antagonized in Pik3cb(R/R) platelets or by inhibiting phosphatidylinositol 3-kinase β (PI3Kβ). Addition of CD40L also enhanced collagen-induced Akt phosphorylation, which was again antagonized by absence or inhibition of PI3Kβ. Finally, platelets from Chuk1(A/A)Apoe(-/-) mice deficient in IκB kinase α (IKKα), implicated in CD40 signaling to nuclear factor (NF) κB, showed unchanged responses to CD40L in aggregation or thrombus formation.

Conclusions: Under atherogenic conditions, CD40L enhances collagen-induced platelet-platelet interactions by supporting integrin αIIbβ3 activation, secretion and thrombus growth via PI3Kβ, but not via CD40 and IKKα/NFκB. This role of CD40L exceeds the no more than modest role of CD40 in thrombus formation.

Keywords: CD40; CD40 ligand; atherosclerosis; atherothrombosis; blood platelets; signal transduction; signaling pathways; thrombosis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Atherosclerosis / metabolism*
Atherosclerosis / pathology
Blood Platelets / metabolism*
CD40 Antigens / metabolism*
CD40 Ligand / metabolism*
Collagen / metabolism
I-kappa B Kinase / metabolism*
Mice
Phosphatidylinositol 3-Kinase / metabolism*
Platelet Activation
Signal Transduction
Thrombosis / metabolism*
Thrombosis / pathology

Substances

CD40 Antigens
CD40 Ligand
Collagen
Phosphatidylinositol 3-Kinase
I-kappa B Kinase