Effect of intracellular zinc on enhancement of Akt and Erk phosphorylation.

<p>(A) Enhancement of Akt and Erk phosphorylation required intracellular zinc. Serum-starved cells were treated with (+) or without (−) 10 µM TPEN for 1 h, before treatment with 0.5 mg/mL anti-IgM antibody (lane 2 and 3), and then treated with 10 and 20 µM ZnPy (lane 4 and 5) or 10 µM CaI (lane 6). (B) The treatment with ZnPy activated the phosphorylation of Akt and Erk. The abbreviation, “unt.” was defined the untreated sample. Serum-starved cells were treated with 0.5 mg/mL anti-IgM antibody (lane 2), 5 and 10 µM ZnCl₂ (lanes 3 and 4), 5 and 10 µM ZnPy (lanes 5 and 6), and 20 µM pyrithione (lane 7) for 10 min. (C) Akt and Erk phosphorylation by ZnPy was enhanced in a time-dependent manner. The abbreviation, “unt.” was defined the untreated sample. Serum-starved cells were treated with 10 µM ZnPy for 5 min (lane 2), 10 min (lane 3), 15 min (lane 4), 30 min (lane 5), and 60 min (lane 6). (D) The inhibitors of PI3K and MEK1/2 inhibited the phosphorylation of Akt and Erk. Serum-starved cells were pretreated with (+) or without (−) LY294002 or U0126, before treatments with 0.5 mg/mL anti-IgM antibody (lanes 1–4) and 10 µM ZnPy (lanes 5–8). All data are representative of three independent experiments.