title: Heat shock protein 70 protects against seizure-induced neuronal cell death in the hippocampus following experimental status epilepticus via inhibition of nuclear factor-κB activation-induced nitric oxide synthase II expression.
abstract: Status epilepticus induces subcellular changes that may eventually lead to neuronal cell death in the hippocampus. Based on an animal model of status epilepticus, our laboratory showed previously that sustained hippocampal seizure activity activates nuclear factor-κB (NF-κB) and upregulates nitric oxide synthase (NOS) II gene expression, leading to apoptotic neuronal cell death in the hippocampus. The present study examined the potential modulatory role of heat shock protein 70 (HSP70) on NF-κB signaling in the hippocampus following experimental status epilepticus. In Sprague-Dawley rats, kainic acid (KA) was microinjected unilaterally into the hippocampal CA3 subfield to induce prolonged bilateral seizure activity. Expression of HSP70 was elevated as early as 1h after the elicitation of sustained seizure activity, followed by a progressive elevation that peaked at 24h. Pretreatment with an antisense oligonucleotide against hsp70 decreased the HSP70 expression, and significantly augmented IκB kinase (IKK) activity and phosphorylation of IκBα, alongside enhanced nuclear translocation and DNA binding activity of NF-κB in the hippocampal CA3 neurons and glial cells. These cellular events were followed by enhanced upregulation of NOS II and peroxynitrite expression 3h after sustained seizure activity that led to an increase of caspase-3 and DNA fragmentation in the hippocampal CA3 neurons 7days after experimental status epilepticus. We concluded that HSP70 protects against apoptotic cell death induced by NF-κB activation and NOS II-peroxynitrite signaling cascade in the hippocampal CA3 and glial cells following experimental status epilepticus via suppression of IKK activity and deactivation of IκBα.
authors.affiliation: Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; Chang Gung University College of Medicine, Kaohsiung, Taiwan; Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
authors.forename: Chiung-Chih
authors.initials: CC
authors.lastname: Chang
authors.affiliation: Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; Chang Gung University College of Medicine, Kaohsiung, Taiwan; Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
authors.forename: Shang-Der
authors.initials: SD
authors.lastname: Chen
authors.affiliation: Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Tsu-Kung
authors.initials: TK
authors.lastname: Lin
authors.affiliation: Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Wen-Neng
authors.initials: WN
authors.lastname: Chang
authors.affiliation: Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Chia-Wei
authors.initials: CW
authors.lastname: Liou
authors.affiliation: Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
authors.forename: Alice Y W
authors.initials: AY
authors.lastname: Chang
authors.affiliation: Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
authors.forename: Samuel H H
authors.initials: SH
authors.lastname: Chan
authors.affiliation: Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; Chang Gung University College of Medicine, Kaohsiung, Taiwan; Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; Department of Biological Science, National Sun Yet-sen University, Kaohsiung, Taiwan. Electronic address: ycchuang@adm.cgmh.org.tw.
authors.forename: Yao-Chung
authors.initials: YC
authors.lastname: Chuang
mesh_terms: D000818:Animals; D056654:CA3 Region, Hippocampal / Q000378:metabolism* / Q000473:pathology; D016923:Cell Death; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D007608:Kainic Acid / Q000633:toxicity; D008297:Male; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D052002:NF-kappa B p50 Subunit / Q000037:antagonists & inhibitors / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013226:Status Epilepticus / Q000139:chemically induced / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology
chemical_list: D018840:HSP70 Heat-Shock Proteins; D016328:NF-kappa B; D052002:NF-kappa B p50 Subunit; D052247:Nitric Oxide Synthase Type II; D007608:Kainic Acid
keywords: BCA; ELISA; EMSA; GFAP; HSP70; Heat shock protein 70; Hippocampus; IKK; IκB; KA; NF-κB; NO; NOS II; Neuronal cell death; Nuclear factor κB; O(2)(−); PBS; PCR; RT; Status epilepticus; aCSF; artificial cerebrospinal fluid; bicinchoninic acid; electrophoretic mobility shift assay; enzyme-linked immunosorbent assay; glial fibrillary acidic protein; hEEG; heat shock protein 70; hippocampal electroencephalography; inhibitory κB; inhibitory κB kinase; kainic acid; nitric oxide; nitric oxide synthase II; nuclear factor-κB; phosphate buffered saline; polymerase chain reaction; reverse transcriptase; superoxide anion