Figure 4
Inhibition of cytoskeleton components and motor proteins in thrombin-stimulated spread platelets. (a) Activity as a function of time for a thrombin-stimulated platelet with addition of the actin polymerization inhibitor cytochalasin D (10 µM) at t = 0 min. Control: addition of solvent without cytochalasin D. (b) Topography and activity maps of the platelet from panel a during the grey marked time intervals before and after the addition of cytochalasin D. (c) Activity as a function of time for a thrombin-stimulated platelet with addition of the specific dynein inhibitor ciliobrevin D (100 µM) or the broad-spectrum dynein inhibitor EHNA (1 mM) at t = 0 min. Control: addition of solvent without the respective inhibitor. (d) Topography and activity maps of the platelets from panel c during the grey marked time intervals before and after the addition of ciliobrevin D or EHNA. (e) Average morphological activity as a function of ciliobrevin D concentration. (f) Average morphological activity of thrombin-stimulated platelets treated with different cytoskeleton and motor protein inhibitors (n = 7 platelets each). In contrast to cytochalasin D, ciliobrevin D, or EHNA, the myosin II inhibitor blebbistatin (100 µM), the ROCK inhibitor Y-27632 (50 µM), the microtubule polymerization inhibitor nocodazole (33 µM), or the kinesin ATPase inhibitor ATA (10 µM) had no significant effect on the activity. The respective image sequences are provided as Supplementary Movies S4 and S5. *(P < 0.05) and ***(P < 0.001) indicate statistically significant difference. Error bars: SEM. Scale bars: 2 µm.
