Involvement of JNK in the inhibition of neural progenitor migration by ET-1. Neurospheres were plated on a cover glass coated with PDL and laminin and pretreated with several concentrations of inhibitors for 30 min before the addition of ET-1. U0126 (□), an inhibitor of MEK1/2, and SB203580 (▵), an inhibitor of p38, had no effect on the ET-1-induced inhibition of neural progenitor cell migration. SP600125 (•), a specific inhibitor of JNK, rescued the inhibitory effect of ET-1. Data are shown as the mean ± SD of at least three independent experiments.