title: Immobilization stress-induced anorexia is mediated independent of MyD88.
abstract: MyD88 is an adaptor protein for the toll-like receptor, which is involved in regulating innate immune function. Lipopolysaccharide-induced activation of toll-like receptor 4 signaling induces hypothalamic signal transducer and activator of transcription 3 (STAT3) phosphorylation and anorexia through MyD88. In the present study, we investigated the possible role of MyD88 in psychological stress-induced anorexia. We found that immobilization stress inhibited food intake in both wild-type mice and MyD88-deficient mice. Immobilization stress slightly increased STAT3 phosphorylation in the hypothalamus, but it was weaker than the lipopolysaccharide-induced increase in STAT3 phosphorylation. These observations suggest that the mechanisms involved in psychological stress-induced anorexia may be regulated differently from those involved in anorexia that is induced by infection.
authors.affiliation: aDepartment of Pharmacotherapy, Graduate School of Biomedical and Health Sciences bDepartment of Cellular and Molecular Pharmacology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Hosoi
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Yamawaki
authors.forename: Hitomi
authors.initials: H
authors.lastname: Kimura
authors.forename: Koichiro
authors.initials: K
authors.lastname: Ozawa
mesh_terms: D000818:Animals; D000855:Anorexia / Q000209:etiology / Q000378:metabolism*; D004435:Eating; D007031:Hypothalamus / Q000378:metabolism; D008297:Male; D008810:Mice, Inbred C57BL; D053594:Myeloid Differentiation Factor 88 / Q000378:metabolism*; D012149:Restraint, Physical; D050796:STAT3 Transcription Factor / Q000378:metabolism; D013315:Stress, Psychological / Q000150:complications / Q000378:metabolism*
chemical_list: C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse