SDF-1 and TPO phosphorylate AKT in normal human αIIbβ3+ cells in a PI-3K–dependent manner.
(A) Western blot analysis of AKT phosphorylation (upper panel) in normal human αIIbβ3+ cells. Cells were nonstimulated (lane 1) or stimulated with 100 ng/mL TPO (lanes 2, 4, 6, 8) or 500 ng/mL of SDF-1 (lanes 3, 5, 7, 9) for 1 minute (lanes 2, 3), 10 minutes (lanes 4, 5), 30 minutes (lanes 6, 7), and 1 hour (lanes 8, 9). Equal loading in the lanes was evaluated by stripping the blot and reprobing with an anti-AKT antibody (lower panel). (B) Densitometric data showing changes in AKT phosphorylation. The experiment was repeated 5 times with similar results. Data are presented from 5 independent experiments. (C) Normal human αIIbβ3+ cells were pretreated with LY294002 and then stimulated with TPO (100 ng/mL) or SDF-1 (500 ng/mL) (not shown). phospho-AKT (upper panel); total AKT (lower panel). The experiment was repeated 3 times with similar results.
