Fig 8. Restoration of αIIbβ3-mediated platelet spreading on Fg by enforced expression of PLCγ1 or PLCγ2 in PLCγ1/γ2 double-deficient platelets.

Lethally irradiated wild-type (WT) mice were reconstituted with WT bone marrow transfected with IRES-GFP retroviruses (WT/GFP) or with PLCγ1/γ2 double-deficient bone marrow transfected with IRES-GFP retroviruses (dKO/GFP), PLCγ1-IRES-GFP retroviruses (dKO/PLCγ1), or PLCγ2-IRES-GFP retroviruses (dKO/PLCγ2). Recipient mice were analyzed 8 weeks after reconstitution. (A) Washed non-sorted platelets from reconstituted recipients were allowed to spread on Fg (3 μg/ml) for 60 minutes at 37°C. Platelets were fixed, permeabilized, and stained for F-actin using TRITC-Phalloidin. (B) Quantitative analysis of mouse platelet spreading on immobilized Fg. Platelet spreading was quantified using Metamorph software (for each genotype, at least 300 platelets were analyzed), platelet spreading area (μm²) and percentage (%) are shown. Quantitative analysis was performed on all non-sorted platelets regardless of GFP positivity. Results are reported as mean ± S.D. from 2 independent experiments (*p < 0.05 for each genotype relative to dKO/GFP). Note that increased platelet spreading area and spreading percentage were observed in PLCγ1/γ2 double-deficient platelets that expressed PLCγ2 or PLCγ1 at levels normally achieved by PLCγ2.