Figure 6. Platelet-dependent COX-2 up-regulation in monocytes and effect of COX inhibitors on monocytic CD16 expression and MPA formation.

(A), Immunofluorescence staining for COX-2 (red) in monocytes cultured in medium alone (M) or with platelets (M+P) for 18 h. Photomicrographs are representative of n = 3 experiments. Change in CD16 expression (B) and MPA (C) in monocytes co-cultured with platelets, expressed as % change in CD14⁺CD16⁺ and CD14⁺CD42b⁺ cells respectively, as compared to monocytes cultured in medium alone, after 48 h. Also shown are the effects of NS-398, SC-560 and aspirin addition to monocyte-platelet co-culture (n = 3–4). *, ** p<0.05 and <0.01 respectively vs M.