Fig. 8.

PGE₂ alters the kinetics of TGF-β1-stimulated MAP kinase activation. A: quiescent human lung fibroblasts (IMR-90) were treated with TGF-β1 (2 ng/ml), or TGF-β1 (2 ng/ml) and PGE₂ (10 nM), under serum-free conditions, and cell lysates were prepared at the times indicated. Cell lysates were subjected to SDS-PAGE followed by immunoblotting with antibodies against pERK1/2, pJNK, or pp38. Blots were then stripped and blotted with antibodies against ERK1/2, JNK, or p38 sequentially. B: densitometry data for n = 3 experiments looking at ERK phosphorylation. C: densitometry data for n = 3 experiments looking at JNK phosphorylation. D: densitometry data for n = 3 experiments looking at p38 phosphorylation. Significance is indicated with # and * symbols as in Fig 4.