Activation of JAK-STAT pathway is required for platelet-derived growth factor-induced proliferation of pancreatic stellate cells

Figure 7 Src, not JAK2, is located upstream of ERK. PSCs were treated with a JAK2 inhibitor AG490 (A) (at 10 or 25 μmol/L), a Src inhibitor PP1 (B) (at 1 or 2.5 μol/L), or a MAP kinase kinase inhibitor U0126 (C) (at 5 or 10 μmol/L) in the absence or presence of PDGF-BB (at 25 ng/mL) for 5 min. Total cell lysates were prepared, and the levels of phosphorylated ERK, STAT1, and STAT3 were determined by Western blotting. The level of total ERK was also determined.