GPVI and {alpha}2{beta}1 play independent critical roles during platelet adhesion and aggregate formation to collagen under flow -- Sarratt et al. 106 (4): 1268 Data Supplement - Supplemental materials for: Sarratt et al, Vol 106, Issue 4, 1268-1277 -- Blood

GPVI and ${alpha}$ ₂ ${beta}$ ₁ play independent critical roles during platelet adhesion and aggregate formation to collagen under flow
Blood Sarratt et al. 106: 1268

Supplemental materials for: Sarratt et al, Vol 106, Issue 4, 1268-1277

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Figure S1. Effect of concentration of the blocking anti-α2 antibody 6F1 on deposition of human platelets on collagen under flow (JPG, 19 KB) -
Human whole blood was treated with 10 µg/mL 6F1 (gray bars), 30 µg/mL 6F1 (white bars), 10 µg/mL mIgG (black bars) and 30 µg/mL mIgG (cross-hatched bars) prior to being perfused over a collagen substrate for 4 minutes. The results shown are the mean percent surface coverage of platelets ± SEM at 1300s^–1 (n = 4).

¹Nieswandt B, Brakebusch C, Bergmeier W, et al. Glycoprotein VI but not alpha2beta1 integrin is essential for platelet interaction with collagen. Embo J. 2001;20:2120-2130.
Figure S2. Effect of the extent of dilution of whole blood on collagen deposition of α2-deficient mouse platelets under flow (JPG, 53 KB) -
To determine whether the defect in adhesion of α2-deficient platelets to collagen under flow might be affected by platelet dilution, whole blood was diluted with 0.5 × volume of heparinized buffer as in a previously published study and perfused over a collagen substrate for 4 minutes. The results shown are the mean ± SEM (n = 4). Statistical significance (P < .05) was seen between the knockouts and the controls at all levels of shear.
Figure S3. Platelets lacking GPVI-FcRγ and integrin α2β1 retain normal responses to ADP and PAR4 peptide but not to collagen (JPG, 32 KB) -
Aggregation dose responses of wild-type (WT) and GPVI-FcRγ^-/-;α₂β₁^-/- (DKO) platelets stimulated with (A) 1µM and 10 µM ADP, (B) 600 µM and 1mM AYPGKF, and (C) 30 µg/mL collagen. Results shown are representative of 2 experiments.
Figure S4. Wild-type platelets retain platelet collagen deposition under flow at platelet counts comparable to those in SLP-76-deficient blood (JPG, 15 KB) -
Wild-type mouse blood was diluted one-fold (black bars) and two-fold (white bars) with modified Tyrode buffer. Diluted blood was perfused over a collagen coated slide for 4 minutes. The results shown are the mean percentage of surface coverage ± SEM after analysis of the phase contrast images (n = 3).