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

Figure 3 Src and JAK2 mediate the activation of STAT1 and STAT3. A: PSCs were treated with PDGF-BB (at 25 ng/mL) for the indicated time. Total cell lysates (approximately 100 μg) were prepared, and separated by 100 g/L SDS-polyacrylamide gel electrophoresis. The activation of Src and JAK2 was examined by Western blotting using anti-phosphospecific antibodies. The level of GAPDH was also determined; B-D: PSCs were treated with a Src inhibitor PP1 (at 1 or 2.5 μmol/L) or a JAK2 inhibitor AG490 (at 10 or 25 μmol/L) in the absence or presence of PDGF-BB (at 25 ng/mL) for 5 min. Total cell lysates (approximately 100 μg) were prepared, and the levels of phosphorylated JAK2, STAT1, STAT3, and PDGF β-receptor were determined by Western blotting. The levels of total STAT3 and GAPDH were also determined.