Figure 2.

Inhibition of JNK kinase attenuates additional dopaminergic apoptosis induced by combined paraquat and iron in both N27 and primary mesencephalic cultures in vitro. N27 cells were treated with the indicated inhibitors 1 h before the addition of 350 μm paraquat or 350 μm paraquat plus 80 μm FeCl₂. A–C, Cleaved caspase-3-positive cells at 18 h (A), TUNEL-positive cells at 24 h (B), and cell viability at 24 h (C) were measured. Mesencephalic cultures were treated with the indicated inhibitors 1 h before the addition of paraquat or paraquat plus FeCl₂. D, E, Cleaved caspase-3-positive cells at 18 h (D) and cell viability at 24 h (E) were measured. Error bars indicate mean ± SEM. n = 4–5. ^#p < 0.05, significantly from paraquat alone; *p < 0.01, significantly from paraquat alone; **p < 0.001, significantly from paraquat plus FeCl₂ alone. Gray bars, Without inhibitors; white bars, SP600125; black bars, CEP-11004.