title: Heat stress activates ER stress signals which suppress the heat shock response, an effect occurring preferentially in the cortex in rats.
abstract: Although heat stress induces a variety of illnesses, there have been few studies designed to uncover the molecular mechanisms underlining the illnesses. We here demonstrate that heat activates ER stress, which inhibits heat shock responses (HSR) via translational block. In heat-stressed rats, ER stress responses, as represented by eIF2α phosphorylation and XBP1 splicing, occurred mainly in the cortex, where the HSR was substantially inhibited. Heat exposure also activated ER stress signals in primary cortical neurons. Since HSF1 knockdown enhanced heat-induced ER stress and subsequent cell death, HSR inhibition in turn augments ER stress, implying a vicious spiral of both stresses. Taken together, heat-induced ER stress impairs the HSR and enhances cell damage, thereby manifesting its unique effect on heat stress.
authors.affiliation: First Department of Internal Medicine, Sapporo Medical University School of Medicine, S-1, W-16, Chuo-Ku, Sapporo, 060-8543, Japan.
authors.forename: Yaohua
authors.initials: Y
authors.lastname: Liu
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Sakamoto
authors.forename: Masaaki
authors.initials: M
authors.lastname: Adachi
authors.forename: Shiguang
authors.initials: S
authors.lastname: Zhao
authors.forename: Wataru
authors.initials: W
authors.lastname: Ukai
authors.forename: Eri
authors.initials: E
authors.lastname: Hashimoto
authors.forename: Masato
authors.initials: M
authors.lastname: Hareyama
authors.forename: Tadao
authors.initials: T
authors.lastname: Ishida
authors.forename: Kohzoh
authors.initials: K
authors.lastname: Imai
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Shinomura
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002540:Cerebral Cortex / Q000378:metabolism* / Q000473:pathology*; D059865:Endoplasmic Reticulum Stress / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D018869:Heat-Shock Response / Q000235:genetics*; D006801:Humans; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000235:genetics*
chemical_list: D006360:Heat-Shock Proteins