Figure 7.

Involvement of the p38 and JNK MAPK pathway in 15d-PGJ₂-induced cell death. Effects of a p38 MAPK inhibitor, SB202190 (A), or JNK inhibitor, SP600125 (B, C), on 15d-PGJ₂-induced cell death and the effects of 15d-PGJ₂ on phosphorylation of JNK (D). Cells were precultured for 24 h at 5 × 10³ /well in 96-well plates and exposed to 15d-PGJ₂ at approximately the IC₅₀ in the presence or absence of SB202190 (3 μM) or SP600125 (0.1, 0.3, 1 μM) for 24 h. Cell viability was assessed by fluorescent assay, and data represent the mean ± S.D. from 4 independent preparations. Statistical significance was assessed by t-test or Dunnett's test. To detect proteins, cells were precultured for 24 h in 100-mm dishes. Cells were then treated with 15d-PGJ₂ at 3 μM for 0 and 8 h. Protein (15 μg) was analyzed by Western blotting for the expression of phospho-JNK. Relative protein levels were quantified using ImageJ, and each phospho-JNK signal was normalized to the β-actin signal. The representative bands and the results of densitometric analysis from three independent preparations were described, and data represent the mean ± S.D. from 4 independent preparations.