SDF-1, but not TPO, stimulates NF-κB activation in human α_IIbβ₃⁺ cells in a PI-3K–dependent manner.

(A) Normal human α_IIbβ₃⁺ cells were made quiescent and subsequently were stimulated with 300 ng/mL SDF-1 (lanes 1, 2, 3) or 100 ng/mL TPO (lanes 5, 6, 7). EMSA was performed with cell nuclear extracts from cells stimulated with SDF-1 for 30 minutes (lane 1), 60 minutes (lane 2), 120 minutes (lane 3), nonstimulated (lane 4), or stimulated with TPO for 30 minutes (lane 5), 60 minutes (lane 6), and 120 minutes (lane 7). A representative autoradiogram of 2 separate experiments is shown. (B) Normal human α_IIbβ₃⁺ cells were made quiescent and then were pretreated with 10 μmol/L or 30 μmol/L (lanes 1 and 2) of MEK inhibitor U0126 or 10 μmol/L or 30 μmol/L PI-3K inhibitor LY294002 (lanes 3 and 4) and stimulated with 300 ng/mL SDF-1. Control, cells pretreated but not stimulated with SDF-1 (lane 5), cells not pretreated but stimulated with SDF-1 (lane 6). EMSA was performed with nuclear extracts from cells stimulated with SDF-1 for 90 minutes. A representative autoradiogram of 2 separate experiments is shown.