Activated Platelets Induce The Expression Of Urokinase-type Plasminogen Activator And Urokinase-type Plasminogen Activator Receptor Expression In Macrophages

OBJECTIVE:To determine the effects of actived platelets on EMMPIRN induced the expression of urokinase-type plasminogen activator and urokinase-type plasminogen activator receptor on macrophages, detective the relationship among them in the atherosclerosis plaque.METHORDS:First different concentrations of ADP were used to stimulate platelets and the mean fluorescence of CD62PE and EMMPIRN was analyzed by Flow cytometry.Secondly the expression of urokinase-type plasminogen activator at different times(12h,15h,18h and21h) were analyzed by Real-time PCR and ELISA.Thirdly activated and unactivated platelets were cocultured with macrophages for18hours, then used Real-time PCR> Western blot and ELISA to analyze the expression of uPA/uPAR.Then used EMMPRIN monoclonal antibody and activated platelets to induce the expression of uPA/uPAR on macrophages.At last EMMPIRN recombinant proteins was used to cetify it.Rusults:ADP is a strong stimulus for the activation of platelets.It could stimulate the expression of P-selectin on platelets.At the concentration of10、20、40μmol/L,the mean fluorescence of CD62PE and EMMPIRN were higher than the unstimulated platelets,but there were no significantly difference among them.At the time of18h,there was a highest expression of uPA.Compared with the unactiatved platelets group, the expression of uPA/uPAR mRNA which were determined by Real-time PCR were higher in activated platelets group(ADP20μmol/L).At the same time,the urokinase-type plasminogen activator in cell culture supernatant of activated platelets were higher than in the unactived platelets by ELISA. EMMPRIN monoclonal antibody could inhibite it.And EMMPIRN recombinant proteins upregulated the expression of uPA/uPAR on macrogages.Conclusion:Activated platelets could induce the expression of uPA/uPAR on macrophages, partly via EMMPIRN.