Figure 3.
Increased fibronectin content in platelets of FgγΔ5 mice by fibronectin internalization mediated by β3 integrin. For each genotype, platelets were isolated from pooled blood of 3 mice. Gel-filtrated platelets (2.5 × 106) were lysed and analyzed by Western blot. Platelet fibronectin (Fn) content was dramatically increased but little fibrinogen (Fg) was detected in FgγΔ5 mice. The platelet fibronectin content in FgγΔ5 mice was similar to Fg-/- mice.10 The increased fibronectin content in FgγΔ5 platelets disappeared when the mice were crossed with β3-/- mice. Platelet fibronectin content of the FgγΔ5/β3 double-deficient mice was similar to that of plasma fibronectin-/- mice (ie, lower than wild-type [WT]).