title: Hyperthermia protects mice against chronic unpredictable stress-induced anxiety-like behaviour and hippocampal CA3 cell apoptosis.
abstract: OBJECTIVE
  It is widely accepted that chronic stress can induce anxiety; however, the cellular and molecular mechanisms of stress-induced anxiety are far from being elucidated. Hyperthermia has been shown to induce expression of heat shock proteins (HSPs) to provide protection against a variety of stresses. To our knowledge, the effect of hyperthermia on the development of chronic unpredictable stress (CUS)-induced anxiety has not been studied. This study was to determine the relationship between hyperthermia induced Hsp72 and CUS related anxiety.
  
  
  METHODS
  Heat shock factor 1 knockout (hsf1(-/-)) and wild-type (hsf1(+/+)) mice were subjected to CUS with or without hyperthermia treatment. Anxiety-like behaviours were evaluated by elevated plus maze and open field tests. Apoptosis in the hippocampal CA3 area was detected by TUNEL staining. Hsp72 protein level in the hippocampus was measured by Western blot.
  
  
  RESULTS
  CUS caused significant apoptosis in hippocampal CA3 cells in both hsf1(-/-) and hsf1(+/+) mice, which significantly correlated with anxiety-like behaviours. Hyperthermia induced Hsp72 expression in hsf1(+/+) mice, but not in hsf1(-/-) mice. Importantly, hyperthermia protected hsf1(+/+) mice against developing CUS-related anxiety-like behaviours and reduced CUS-induced apoptosis in hippocampal CA3 cells. In contrast, hyperthermia exhibited no protective role in hsf1(-/-) mice.
  
  
  CONCLUSIONS
  Apoptosis of hippocampal CA3 cells is involved in the development of anxiety-like behaviours underlying CUS. Hsp72 protein is a crucial player in the protective effect of hyperthermia against CUS-induced apoptosis and development of anxiety-like behaviours. Our study suggests hyperthermia is an effective treatment for CUS-induced mood disorders.
authors.affiliation: Medical Psychological Institute, Second XiangYa Hospital, Central South University, Changsha, Hunan, China.
authors.forename: Xiongzhao
authors.initials: X
authors.lastname: Zhu
authors.forename: Min
authors.initials: M
authors.lastname: Peng
authors.forename: Ming
authors.initials: M
authors.lastname: Cheng
authors.forename: Xianzhong
authors.initials: X
authors.lastname: Xiao
authors.forename: Jingyao
authors.initials: J
authors.lastname: Yi
authors.forename: Shuqiao
authors.initials: S
authors.lastname: Yao
authors.forename: Xiuwu
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001007:Anxiety / Q000517:prevention & control*; D001008:Anxiety Disorders; D017209:Apoptosis; D001522:Behavior, Animal; D056654:CA3 Region, Hippocampal / Q000166:cytology* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000172:deficiency; D050884:HSP72 Heat-Shock Proteins / Q000096:biosynthesis; D000076249:Heat Shock Transcription Factors; D006979:Hyperthermia, Induced; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D012149:Restraint, Physical; D013315:Stress, Psychological / Q000503:physiopathology*; D014157:Transcription Factors / Q000172:deficiency; D015854:Up-Regulation
chemical_list: D004268:DNA-Binding Proteins; D050884:HSP72 Heat-Shock Proteins; D000076249:Heat Shock Transcription Factors; C490017:Hsf1 protein, mouse; D014157:Transcription Factors