oxLDL potentiates GPVI-mediated platelet aggregation, platelet PS exposure, and platelet-driven fibrin formation. Replicate samples of washed human platelets (2 × 10⁸/mL, in modified HEPES/Tyrode buffer without additional calcium) were incubated with the GPVI-specific agonist CRP-XL) alone (0.1, 0.5, 1 μg/mL), oxLDL alone (20 μg/mL), and oxLDL in combination with CRP-XL. Platelet samples were monitored at 37°C under continuous stirring at 1200 rpm and changes in light transmission were measured (A-D). (E) Washed platelets (2 × 10⁸/mL) were incubated with oxLDL (0, 20 μg/mL) in combination with CRP-XL (0, 0.1, 0.5, 1 μg/mL) and monitored using luciferase enzyme activity (CHRONO-LUME) to detect ATP released as a measure of platelet dense granule secretion. (F) Platelets were stained with APC-CD62P to monitor for platelet surface expression of P-selectin as a marker of α-granule secretion and (G) stained with FITC-PAC-1 to monitor for platelet surface integrin activation. (H) Platelets were incubated with oxLDL (0, 20 μg/mL) in combination with GPVI-specific agonist CRP-XL (0, 0.1, 0.5, 1 μg/mL) before fixation and staining with FITC-lactadherin to monitor for platelet surface PS exposure. (I) Platelets were similarly assessed with FITC-lactadherin staining in response to oxLDL and CRP-XL stimulation after a 10-minute preincubation with CD36 inhibitors Fx-5A (250 μM), sulfo-N-succinimidyl oleate (“sulfo,” 50 μM), or FA6-152 (5 μg/mL). (J) Platelets were incubated with CaCl₂ (8.3 mM) and citrated PPP (33% final). Fibrin formation was measured as a change in turbidity at an absorbance of 405 nm. (K) Representative traces are shown and the lag time was calculated. Statistical analysis was performed using a one-way ANOVA test and the corresponding P values of significance are as indicated: ∗P < .05, ∗∗P < .01, and ∗∗∗P < .001. ATP, adenosine triphosphate; CaCl₂, calcium dichloride; FITC, fluorescein isothiocyanate; HEPES, N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid; PPP, platelet-poor plasma.