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.).
Arterioscler Thromb Vasc Biol. 2015 Jun;35(6):1374-81. doi: 10.1161/ATVBAHA.114.305127. Epub 2015 Apr 23.
To investigate the roles and signaling pathways of CD40L and CD40 in platelet-platelet interactions and thrombus formation under conditions relevant for atherothrombosis.
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.
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.
探讨 CD40L 和 CD40 在与动脉粥样硬化相关条件下血小板-血小板相互作用和血栓形成中的作用和信号通路。
缺乏 CD40L（Cd40lg(-/-)Apoe(-/-)）的易患动脉粥样硬化的小鼠血小板对糖蛋白 VI 刺激的 αIIbβ3 活化和α-颗粒分泌反应减弱，而 CD40 缺陷血小板（Cd40(-/-)Apoe(-/-)）的这些反应没有减少。使用来自 Cd40lg(-/-)Apoe(-/-)和 Cd40(-/-)Apoe(-/-)小鼠的血液，与 Apoe(-/-)血液相比，糖蛋白 VI 依赖性致密血栓的形成在动脉粥样硬化斑块物质或胶原上受损。在所有基因型中，将 CD40L 添加到血液中可增强斑块和胶原上致密血栓的生长。同样，CD40L 增强了即使在缺乏 CD40 的血小板中也能诱导糖蛋白 VI 诱导的血小板聚集。这种增强作用被 Pik3cb(R/R)血小板或抑制磷脂酰肌醇 3-激酶β（PI3Kβ）拮抗。添加 CD40L 还增强了胶原诱导的 Akt 磷酸化，而 PI3Kβ 的缺失或抑制再次拮抗了这一作用。最后，缺乏 IκB 激酶α（IKKα）的 Chuk1(A/A)Apoe(-/-)小鼠的血小板，该激酶在 CD40 向核因子（NF）κB 的信号转导中起作用，在聚集或血栓形成中对 CD40L 的反应没有改变。
在动脉粥样硬化条件下，CD40L 通过 PI3Kβ支持整合素 αIIbβ3 的激活、分泌和血栓生长，增强胶原诱导的血小板-血小板相互作用，但不是通过 CD40 和 IKKα/NFκB。CD40L 的这种作用超过了 CD40 在血栓形成中的作用。
