The effects of active MMP-2 on platelets are abolished in Glanzmann thrombasthenia (GT). (A) Washed platelets from controls or GT patients were preincubated with active MMP-2 (0.75 nM) for 5 minutes and then activated with a subthreshold dose of ADP (0.5-1 μM). Results are reported as percentage increase CD62P expression vs ADP. Data represent means ± SEM (n = 3); *P < .05 vs control. (B) GT or control washed platelets were treated for 10 minutes with thrombin (1 nM) or MMP-2 (0.75-1.5 nM) at 37°C. PAR1 N terminus was assessed by western blotting with anti–N-terminus PAR1 antibody (Novus Biologicals), and bands were measured using QUANTISCAN software. Data represent means ± SEM (n = 3); *P < .05 vs unstimulated.