Abstract:

Objective  To investigate the effects of platelets surface CD40L attained in vivo on the endothelial inflammatory reaction. Methods  CD62P and CD40L expressed on platelets were measured by flow cytometry in patients with acute myocardial infraction (AMI group, n=20) and healthy people (normal control group, n=20). Platelets were isolated from the two groups, and then were co-incubated with cultured human umbilical vein endothelial cells (HUVECs) respectively. Membrane-bound intercellular adhesion molecule-1(ICAM-1), E-selectin and soluble interleukin-8 (IL-8) produced by HUVECs were measured with flow cytometry and ELISA respectively. Results  The CD62P and CD40L expressions significantly increased in the AMI group compared with those in the normal control group (P<0.01). Platelets of the AMI group up-regulated the production of ICAM-1, E-selectin and IL-8 in HUVECs (all P<0.01). CD40L-specific monoclonal antibody could prohibit the high expression of inflammatory cytokines in the AMI group (P<0.01), while the platelets of normal control group had no effect on the induction of inflammatory cytokines (P>0.05). Conclusion  Activated platelets in AMI patients   have a high expression of CD40L and induce endothelial cells to express inflammatory cytokines at the same time.

Key words: CD40L, Endothelium, Platelets, Acute myocardial infraction, Inflammation, Activated in vivo