Figure 4.
Accelerated clot retraction of thymosin β4 knockout platelets. (A) Clot retraction of wild-type (WT) and Tmsb4x knockout (KO) platelet-rich plasma (PRP) was determined in response to 4 U mL-1 thrombin and monitored over time. (B) Residual volume at the end of the experiment. Values are mean ± standard deviation (SD) (n=6 per group). Unpaired, two-tailed Student’s t-test. *P<0.05. (C) Analysis of the fibrin meshwork of WT and Tmsb4x KO clots. Washed platelets were labeled with an anti-GPIX Alexa 647 derivative and added to a mix of unlabeled fibrinogen (2 mg mL-1) and Alexa Fluor A488-labeled fibrinogen (50 mg mL-1 f.c.). Platelets were stimulated with 0.1 U mL-1 thrombin and clotting was initiated by addition of 5 mM CaCl2. The mixture was immediately transferred to an uncoated 8-well chamber slide (Ibidi), and allowed to clot. Images were obtained using a Leica SP8 inverted microscope with a 63x oil immersion lens. Optical z-stacks were deconvolved and are shown as maximum projection. Images are representatives of at least 2 z-stacks per mouse and 4 animals per group.