Figure 8.

Involvements of MAPK signaling pathway in CPS-induced apoptosis in ALI cultures of sheep bronchial epithelial cells. Cells were pretreated with (a) U0126 (an ERK1/2 inhibitor, 10 μM), (c) SP600125 (a JNK inhibitor, 20 μM), or (e) SB203580 (a P38 inhibitor, 20 μM) for 1 h, followed by exposure to CPS (100 ng/mL) or MO (MOI = 30) for 48 h. (a, c, e) Cell lysates were subjected to Western blotting analysis using indicated antibodies, showing that inhibitors of JNK (SP600125) and p38 (SB203580) but not ERK1/2 (U0126) significantly blocked the expression of CPS-induced apoptotic proteins. The immunoblots shown here were representative of three independent experiments with similar results. (b, d, f) Densitometric values for representative blots indicated proteins shown in (a), (c), and (e), respectively. β-actin was used as an internal control, and proteins were semiquantified by a densitometric analysis by calculating the fold of change of a protein of interest over respective β-actin.