Fig. 5.

Effect of ERK1/2 and JNK inhibitors on HSP47 expression after treatment of HK-2 cells with TGF-β₁. HK-2 cells were pretreated with varying doses of PD-98059 (ERK1/2 inhibitor) or SP-600125 (JNK inhibitor) for 60 min and then treated with TGF-β₁ (10 ng/ml) for 24 h. A: RT-PCR analyses revealed that the expression of HSP47 was markedly decreased in a dose-dependent manner in cells treated with PD-98059 (1) or SP-600125 (2). B,1 and 2: Western blot analyses confirmed the results determined by RT-PCR analyses. B,3 and 4: there were no changes in cells treated with SB-202474, a negative control for PD-98059, or with SP-ve, an inactive analog of SP-600125. The bar graphs (A,1a and 2a, and B,1a, 2a, 3a, and 4a) represent density analyses of the bands from RT-PCR and Western blots. Values are expressed as means ± SE; n = 6. *P < 0.05 vs. the control group (0 μM); #P < 0.05 vs. 25 μM PD-98059 or 10 μM SP-600125; $P < 0.05 vs. 50 μM PD-98058 or 20 μM SP-00125.