title: Temporal profiles of high-mobility group box 1 expression levels after cortical spreading depression in mice.
abstract: BACKGROUND
  Cortical spreading depression (CSD) has recently been shown to induce the release of the nuclear protein termed high-mobility group box 1 from neurons, causing activation of the trigeminovascular system. Here, we explored the effects of single and multiple cortical spreading depression inductions on high-mobility group box 1 (HMGB1) transcriptional activity relative to high-mobility group box 1 protein expression levels and intracellular localization in cortical neurons and astrocytes.
  
  
  METHODS
  Single or multiple cortical spreading depression inductions were achieved by KCl application to the mouse cerebral cortex. The animals were sacrificed at 30 minutes, 3 hours and 24 hours after cortical spreading depression induction. High-mobility group box 1 expression levels were explored with in situ hybridization, Western blotting and immunostaining.
  
  
  RESULTS
  Cortical spreading depression up-regulated high-mobility group box 1 transcriptional activity in neurons at 3 hours in a manner that was dependent on the number of cortical spreading depression inductions. At 24 hours, the high-mobility group box 1 transcriptional activity had returned to basal levels. Cortical spreading depression induced a reduction in high-mobility group box 1 protein expression at 3 hours, which was also dependent on the number of cortical spreading depression inductions. Following cortical spreading depression, the release of high-mobility group box 1 from the nucleus was observed in a small proportion of neurons, but not in astrocytes.
  
  
  CONCLUSIONS
  Cortical spreading depression induced translocation of high-mobility group box 1 from neuronal nuclei, driving transcriptional up-regulation of high-mobility group box 1 to maintain protein levels.
authors: Department of Neurology, Keio University School of Medicine, Japan.
authors: Tsubasa
authors: T
authors: Takizawa
authors: Department of Neurology, Keio University School of Medicine, Japan mshibata@a7.keio.jp.
authors: Mamoru
authors: M
authors: Shibata
authors: Department of Neurology, Keio University School of Medicine, Japan.
authors: Yohei
authors: Y
authors: Kayama
authors: Department of Neurology, Keio University School of Medicine, Japan.
authors: Haruki
authors: H
authors: Toriumi
authors: Department of Neurology, Keio University School of Medicine, Japan.
authors: Taeko
authors: T
authors: Ebine
authors: Department of Neurology, Keio University School of Medicine, Japan.
authors: Anri
authors: A
authors: Koh
authors: Department of Neurology, Keio University School of Medicine, Japan.
authors: Toshihiko
authors: T
authors: Shimizu
authors: Department of Neurology, Keio University School of Medicine, Japan.
authors: Norihiro
authors: N
authors: Suzuki
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D013181:Cortical Spreading Depression / Q000502:physiology*; D005786:Gene Expression Regulation; D024243:HMGB1 Protein / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010296:Parietal Lobe / Q000378:metabolism*; D013997:Time Factors
chemical_list: D024243:HMGB1 Protein; C582808:HMGB1 protein, mouse
keywords: Cortical spreading depression; astrocyte; high-mobility group box 1; neuron; transcriptional activity