Platelet-derived MPs can deliver functional Ago2•microRNA effector complexes to HUVEC. (A) HUVEC were incubated with platelet-derived MPs for up to 48 hours, and miR-223 accumulation in HUVEC was quantitated by qPCR. Results were normalized by the 2^-ΔΔCt method, using RNU6 as a reference,27 and expressed as the mean (±SEM) fold changes vs baseline (n = 5 experiments). (B) HUVEC transiently expressing a Rluc reporter gene, harboring a binding site complementary to miR-223 (pRL-CMV-BS miR-223), were incubated (or not; control) with MPs derived from thrombin-activated platelets for 48 hours prior to luciferase activity measurements. Results were normalized on Fluc activity, and expressed as mean (±SEM) percentage of control (n = 4 experiments). *P < .05; **P < .01 vs baseline or control (Student t test). pRL-CMV, Renilla luciferase–cytomegalovirus (CMV) plasmid; BS miR-223, Binding site for miR-223.
