TLR2 ligand increases GP1b and CD41 gene and protein expression, and expression is dependent on TLR2. (A-B) Meg-01 cells were pretreated for 45 minutes with 50μM LY294002, U0126, BAY11-7082, or DMSO, and then treated for 3 hours with 1 μg/mL of Pam3CSK4 (PAM). Gene expression was compared with NT. **P < .01 and ***P < .001 compared with NT (n = 13 in panel A and n = 10 in panel B). WT (C) and TLR2−/− (D) mouse bone marrow was cultured with 50 ng/mL of mTPO for 4 days, and then treated with 1 μg/mL of Pam3CSK4 (PAM) for 3 hours. Megakaryocytes were isolated by magnetic bead separation, and gene expression was measured for CD41, GP1b, MCP-1, COX2, TLR2, and NFκB1, all compared with NT (n = 3). *P < .05, **P < .01, and ***P < .001 compared with NT.