Depletion of 14-3-3 zeta elicits endoplasmic reticulum stress and cell death, and increases vulnerability to kainate-induced injury in mouse hippocampal cultures.
14-3-3 proteins are ubiquitous signalling molecules that regulate development and survival pathways in brain. Altered expression and cellular localization of 14-3-3 proteins has been implicated in neurodegenerative diseases and in neuronal death after acute neurological insults, including seizures. Presently, we examined expression and function of 14-3-3 isoforms in vitro using mouse organotypic hippocampal cultures. Treatment of cultures with the endoplasmic reticulum (ER) stressor tunicamycin caused an increase in levels of 14-3-3 zeta within the ER-containing microsomal fraction, along with up-regulation of Lys-Asp-Glu-Leu-containing proteins and calnexin, and the selective death of dentate granule cells. Depletion of 14-3-3 zeta levels using small interfering RNA induced both ER stress proteins and death of granule cells. Treatment of hippocampal cultures with the excitotoxin kainic acid increased levels of Lys-Asp-Glu-Leu-containing proteins and microsomal 14-3-3 zeta levels and caused cell death within the CA1, CA3 and dentate gyrus of the hippocampus. Kainic acid-induced damage was significantly increased in each hippocampal subfield of cultures treated with small interfering RNA targeting 14-3-3 zeta. The present data indicate a role for 14-3-3 zeta in survival responses following ER stress and possibly protection against seizure injury to the hippocampus.
Murphy
Niamh
N
Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland, UK.
Bonner
Helena P
HP
Ward
Manus W
MW
Murphy
Brona M
BM
Prehn
Jochen H M
JH
Henshall
David C
DC
D048948:14-3-3 Proteins / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D037281:Calnexin / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D004721:Endoplasmic Reticulum / Q000187:drug effects; D018690:Excitatory Amino Acid Agonists / Q000633:toxicity*; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects*; D007608:Kainic Acid / Q000633:toxicity*; D051379:Mice; D009474:Neurons / Q000187:drug effects / Q000648:ultrastructure; D009842:Oligopeptides / Q000378:metabolism; D009924:Organ Culture Techniques; D021382:Protein Sorting Signals; D034741:RNA, Small Interfering / Q000494:pharmacology; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D014415:Tunicamycin / Q000494:pharmacology*; D015854:Up-Regulation / Q000187:drug effects; D014701:Veratridine / Q000494:pharmacology
D048948:14-3-3 Proteins; D018690:Excitatory Amino Acid Agonists; D009842:Oligopeptides; D021382:Protein Sorting Signals; D034741:RNA, Small Interfering; D014415:Tunicamycin; C073762:lysyl-aspartyl-glutamyl-leucine; D037281:Calnexin; D014701:Veratridine; D007608:Kainic Acid