Phosphorylation of 14-3-3ζ at serine 58 and neurodegeneration following kainic acid-induced excitotoxicity.

Oxidative stress-induced cell death leads to phosphorylation of 14-3-3ζ at serine 58. 14-3-3ζ is detected at significant levels in cerebrospinal fluid after kainic acid (KA)-induced seizures. Here we examined temporal changes in 14-3-3ζ phosphorylation in the hippocampus and amygdala of mice after KA treatment. Mice were killed at 2, 6, 24, or 48 h after KA (30 mg/kg) injection. We observed an increase in TUNEL and Fluoro-Jade B (FJB)-stained neurons in the hippocampus and amygdala of KA-treated mice. Phospho (p)-14-3-3ζ and p-JNK expression was increased in the hippocampus 2 and 6 h after KA treatment, respectively. In immunohistochemical analysis, p-14-3-3ζ-positive cells were present in the CA3 region of the hippocampus and the central nucleus of amygdala (CeA) of KA-treated mice. Thus, phosphorylation of 14-3-3ζ at serine 58 may play an important role in KA-induced hippocampal and amygdaloid neuronal damage.

Adiponectin protects hippocampal neurons against kainic acid-induced excitotoxicity.

Neuronal damage after seizure is correlated with blood-brain barrier (BBB) leakage. Adiponectin (Ad) has shown protective effects on endothelial function. In this study, we investigated the effects of Ad on cell survival and BBB integrity in the mouse hippocampus after kainic acid (KA) treatment. Twenty-four hours after intracerebroventricular injection of recombinant Ad, mice were treated with KA, and then sacrificed 48 h later. Decreased serum Ad and increased hippocampal Ad receptor 1 in the hippocampus of KA-treated mice were prevented by Ad pretreatment. Using cresyl violet staining, TUNEL analysis, and immunostaining for caspase-3, histological evaluation revealed that the marked cell death noted in the hippocampus of KA-treated mice was not observed in KA-treated mice pretreated with Ad. Impairment of the BBB, which was demonstrated by the presence of IgG, was inhibited by Ad pretreatment. Immunohistochemical analysis indicated that KA caused up-regulation of hippocampal VEGF, eNOS, and NF-kappaB levels, all of which were reduced in animals that received Ad pretreatment. These data indicate that Ad preserves the integrity of the BBB and has neuroprotective effects in an animal model of seizures.