Fig. 4

CaMKKβ as an upstream kinase of AMPK was not involved in zinc neurotoxicity. a Microscopic images (left) and quantitative data (right, mean ± SEM, n = 3 cultures) of Hoechst 33342-stained total nuclei (upper) and TUNEL-positive apoptotic nuclei (lower) of the same field in mouse cortical near-pure neuronal cultures at 12 h after a 10-min exposure to 300 μM zinc with or without 10 μM STO-609 (STO), a CaMKKβ inhibitor. Arrows indicate apoptotic nuclei. Scale bar, 25 μm. *p < 0.05 compared to zinc-exposed cultures, two-tailed t-test. Zinc-induced neuronal cell death was markedly attenuated by STO. b Representative western blots and quantitation of phosphorylated AMPK (n = 3/group, *p < 0.05). Protein samples were prepared from near-pure neuronal cultures at 4 h after 300 μM zinc treatment for 10 min with or without 10 μM STO-609. Phosphorylation of AMPK was not reduced by STO-609