Figure 2.
Figure 2. CD40-CD40L system as an example of platelet-endothelial interaction. / Shown are three endothelial cells and two platelets (not drawn to scale). Platelet activation results in increased expression of CD40 and CD40 ligand (CD40L). GPIIbIIIa-dependent adhesion of platelets to the endothelium results in CD40L-induced activation of endothelial cells with secondary induction of tissue factor, cytokines, adhesion molecules, metalloproteinases (MMP), urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), and urokinase receptor (u-PAR). Thus, the platelet indirectly orchestrates (via the endothelium) changes in coagulation, leukocyte trafficking, and extracellular matrix modeling/turnover. At the same time, the inter-action between platelet and endothelial cells results in GPIIbIIIa-mediated outside-in signaling with secondary induction of CD40L and CD62P (P-selectin) expression on the platelet surface. In addition, soluble trimeric CD40L (sCD40L), released from activated platelets, may engage platelet CD40 in an autocrine or paracrine manner (indicated by +), resulting in shape change and α-granule release. / Based in part on Inwald DP, McDowall A, Peters MJ, Callard RE, Klein NJ. CD40 is constitutively expressed on platelets and provides a novel mechanism for platelet activation. Circ Res. 2003 May 16;92(9):1041–1048 . Epub 2003 Apr 03 and May AE, Kalsch T, Massberg S, Herouy Y, Schmidt R, Gawaz M. Engagement of glycoprotein IIb/IIIa (alpha(IIb)beta3) on platelets upregulates CD40L and triggers CD40L-dependent matrix degradation by endothelial cells. Circulation. 2002;106(16):2111–2117.

CD40-CD40L system as an example of platelet-endothelial interaction.

Shown are three endothelial cells and two platelets (not drawn to scale). Platelet activation results in increased expression of CD40 and CD40 ligand (CD40L). GPIIbIIIa-dependent adhesion of platelets to the endothelium results in CD40L-induced activation of endothelial cells with secondary induction of tissue factor, cytokines, adhesion molecules, metalloproteinases (MMP), urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), and urokinase receptor (u-PAR). Thus, the platelet indirectly orchestrates (via the endothelium) changes in coagulation, leukocyte trafficking, and extracellular matrix modeling/turnover. At the same time, the inter-action between platelet and endothelial cells results in GPIIbIIIa-mediated outside-in signaling with secondary induction of CD40L and CD62P (P-selectin) expression on the platelet surface. In addition, soluble trimeric CD40L (sCD40L), released from activated platelets, may engage platelet CD40 in an autocrine or paracrine manner (indicated by +), resulting in shape change and α-granule release.

Based in part on

Inwald DP, McDowall A, Peters MJ, Callard RE, Klein NJ. CD40 is constitutively expressed on platelets and provides a novel mechanism for platelet activation. Circ Res. 2003 May 16;92(9):1041–1048
. Epub 2003 Apr 03 and
May AE, Kalsch T, Massberg S, Herouy Y, Schmidt R, Gawaz M. Engagement of glycoprotein IIb/IIIa (alpha(IIb)beta3) on platelets upregulates CD40L and triggers CD40L-dependent matrix degradation by endothelial cells. Circulation. 2002;106(16):2111–2117.

Close Modal
This Feature Is Available To Subscribers Only

or Create an Account

Close Modal
Close Modal