Inhibition of p38 MAPK during storage improves the posttransfusion recovery and hemostatic function of platelets. (A) Platelets from fresh PRP or PRP stored in the presence of DMSO (stored) or SB203580 (40μM; stored/SB203580) were washed and labeled with 2 μg/mL CFSE. A total of 108 platelets/10 g of body weight was infused intravenously into a wild-type mouse. At the indicated time points, blood was drawn and analyzed by flow cytometry. Results are mean percentage of labeled platelets ± SEM; n = 6. (B) FeCl3-induced thrombosis was studied in mesenteric arterioles of mice transfused with 0.5 × 108 SB203580/stored platelets labeled with calcein-red/orange and 1.5 × 108 vehicle/stored platelets labeled with calcein-green. Platelet adhesion (tethering) and thrombus growth were monitored until complete vessel occlusion occurred (occlusion). Representative images are shown. (C) IL4Rα/GPIb-α-tg mice were transfused with the indicated platelet preparations (108 platelets/10 g of body weight). The tail bleeding time was measured 1 hour after platelet transfusion. n.s. indicates not significant.
