FIGURE 5.

JNK inhibitor SP600125 prevents cPLA₂α activation and LD biogenesis induced by FBS. Serum-deprived CHO-K1 cells were pretreated for 30 min with 10 μm concentrations of SP600125, SB20358, or PD98059 and then challenged with 7.5% FBS for 15 min (B) or 6 h (A and C). A, Western blots of total cPLA2α, phospho-Ser-505-cPLA2α, and ADRP. B, radioactivity released from serum-deprived CHO-K1 cells that were prelabeled during 24 h with 0.5 μCi/ml [³H]AA, washed, and pretreated with drugs for 30 min before a 15-min stimulation with 7.5% FBS. C, serum-starved cells were treated for 30 min with drugs, then stimulated with FBS during 6 h, fixed, and stained with Nile red to quantify LD by flow cytometry. Results in B and C are means ± S.E. of three independent experiments. *, p < 0.01 compared with control in the absence of FBS; #, p < 0.01 compared with FBS-treated cells.