title: Hypothermia-induced tyrosine phosphorylation of SIRPα in the brain.
abstract: Signal regulatory protein α (SIRPα) is a neuronal membrane protein that undergoes tyrosine phosphorylation in the brain of mice in response to forced swim (FS) stress in cold water, and this response is implicated in regulation of depression-like behavior in the FS test. We now show that subjection of mice to the FS in warm (37 °C) water does not induce the tyrosine phosphorylation of SIRPα in the brain. The rectal temperature (T(rec) ) of mice was reduced to 27° to 30 °C by performance of the FS for 10 min in cold water, whereas it was not affected by the same treatment in warm water. The level of tyrosine phosphorylation of SIRPα in the brain was increased by administration of ethanol or picrotoxin, starvation, or cooling after anesthesia, all of which also induced hypothermia. Furthermore, the tyrosine phosphorylation of SIRPα in cultured hippocampal neurons was induced by lowering the temperature of the culture medium. CD47, a ligand of SIRPα, as well as Src family kinases or SH2 domain-containing protein phosphatase 2 (Shp2), might be important for the basal and the hypothermia-induced tyrosine phosphorylation of SIRPα. Hypothermia is therefore likely an important determinant of both the behavioral immobility and tyrosine phosphorylation of SIRPα observed in the FS test.
authors.affiliation: Laboratory of Biosignal Sciences, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma, Japan.
authors.forename: Toshi
authors.initials: T
authors.lastname: Maruyama
authors.forename: Shinya
authors.initials: S
authors.lastname: Kusakari
authors.forename: Miho
authors.initials: M
authors.lastname: Sato-Hashimoto
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Takenori
authors.initials: T
authors.lastname: Kotani
authors.forename: Yoji
authors.initials: Y
authors.lastname: Murata
authors.forename: Hideki
authors.initials: H
authors.lastname: Okazawa
authors.forename: Per-Arne
authors.initials: PA
authors.lastname: Oldenborg
authors.forename: Shoji
authors.initials: S
authors.lastname: Kishi
authors.forename: Takashi
authors.initials: T
authors.lastname: Matozaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohnishi
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D007035:Hypothermia / Q000378:metabolism*; D015151:Immunoblotting; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009474:Neurons / Q000378:metabolism*; D010766:Phosphorylation; D034622:RNA Interference; D011971:Receptors, Immunologic / Q000378:metabolism*; D013315:Stress, Psychological / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism
chemical_list: C501922:Sirpa protein, mouse; D011971:Receptors, Immunologic; D014443:Tyrosine