title: Dexamethasone enhances NT-3 expression in rat hippocampus after traumatic brain injury.
abstract: The cellular events in traumatic brain injury (TBI) are complicated, and the factors mediating neurotrophins to protect and repair the injured brain cells are only beginning to be identified. This study examined the effect of dexamethasone (DEX) on neurotrophin-3 (NT-3) expression following TBI. Levels of NT-3 mRNA and protein in rat hippocampus were measured using in situ hybridization and immunohistochemistry, respectively. After TBI, the NT-3 mRNA expression was down-regulated during the first 24 h. DEX reversed the post-traumatic reduction of NT-3 mRNA expression at 2, 4, 6, and 12 h in the hippocampus, and also decreased the cell death in hippocampal hilum and supraventricular cerebral cortex after 7 days. The NT-3 protein levels generally corresponded to the mRNA levels in the hippocampal region. DEX enhanced the NT-3 expression after TBI, indicating that post-traumatic neuroprotection in the hippocampus is at least partially mediated by NT-3 and thus can be modulated by DEX treatment.
authors.affiliation: Departments of Neurosurgery, Chang Gung Memorial Hospital, Chia-Yi, Taiwan.
authors.forename: Jen-Tsung
authors.initials: JT
authors.lastname: Yang
authors.forename: Tsong-Hai
authors.initials: TH
authors.lastname: Lee
authors.forename: Hsu-Huei
authors.initials: HH
authors.lastname: Weng
authors.forename: Chen-Nen
authors.initials: CN
authors.lastname: Chang
authors.forename: Wen-Cheng
authors.initials: WC
authors.lastname: Chen
authors.forename: Wan-Chun
authors.initials: WC
authors.lastname: Cheng
authors.forename: June Hsieh
authors.initials: JH
authors.lastname: Wu
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D001930:Brain Injuries / Q000188:drug therapy / Q000378:metabolism*; D002452:Cell Count / Q000379:methods; D003907:Dexamethasone / Q000494:pharmacology* / Q000627:therapeutic use; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D007150:Immunohistochemistry / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D008297:Male; D020933:Neurotrophin 3 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013194:Staining and Labeling / Q000379:methods; D013997:Time Factors
chemical_list: D000893:Anti-Inflammatory Agents; D020933:Neurotrophin 3; D012333:RNA, Messenger; D003907:Dexamethasone