title: Absence of heat shock transcription factor 1 retards the regrowth of atrophied soleus muscle in mice.
abstract: Effects of heat shock transcription factor 1 (HSF1) gene on the regrowth of atrophied mouse soleus muscles were studied. Both HSF1-null and wild-type mice were subjected to continuous hindlimb suspension for 2 wk followed by 4 wk of ambulation recovery. There was no difference in the magnitude of suspension-related decrease of muscle weight, protein content, and the cross-sectional area of muscle fibers between both types of mice. However, the regrowth of atrophied soleus muscle in HSF1-null mice was slower compared with that in wild-type mice. Lower baseline expression level of HSP25, HSC70, and HSP72 were noted in soleus muscle of HSF1-null mice. Unloading-associated downregulation and reloading-associated upregulation of HSP25 and HSP72 mRNA were observed not only in wild-type mice but also in HSF1-null mice. Reloading-associated upregulation of HSP72 and HSP25 during the regrowth of atrophied muscle was observed in wild-type mice. Minor and delayed upregulation of HSP72 at mRNA and protein levels was also seen in HSF1-null mice. Significant upregulations of HSF2 and HSF4 were observed immediately after the suspension in HSF1-null mice, but not in wild-type mice. Therefore, HSP72 expression in soleus muscle might be regulated by the posttranscriptional level, but not by the stress response. Evidence from this study suggested that the upregulation of HSPs induced by HSF1-associated stress response might play, in part, important roles in the mechanical loading (stress)-associated regrowth of skeletal muscle.
authors.affiliation: Department of Orthopaedic Surgery, St. Marianna University School of Medicine, Kawasaki, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Yasuhara
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Ohno
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kojima
authors.forename: Kenji
authors.initials: K
authors.lastname: Uehara
authors.forename: Moroe
authors.initials: M
authors.lastname: Beppu
authors.forename: Takao
authors.initials: T
authors.lastname: Sugiura
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Fujimoto
authors.forename: Akira
authors.initials: A
authors.lastname: Nakai
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Ohira
authors.forename: Toshitada
authors.initials: T
authors.lastname: Yoshioka
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Goto
mesh_terms: D000818:Animals; D001835:Body Weight / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D015536:Down-Regulation / Q000235:genetics; D050883:HSC70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D050884:HSP72 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D019417:Hindlimb Suspension / Q000379:methods; D008297:Male; D051379:Mice; D018832:Molecular Chaperones; D018485:Muscle Fibers, Skeletal / Q000378:metabolism* / Q000473:pathology; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D009133:Muscular Atrophy / Q000235:genetics* / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D015854:Up-Regulation / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; D050883:HSC70 Heat-Shock Proteins; D050884:HSP72 Heat-Shock Proteins; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; C486113:Hsbp1 protein, mouse; C490017:Hsf1 protein, mouse; C484462:Hsf4 protein, mouse; C494372:Hspa8 protein, mouse; D018832:Molecular Chaperones; D009124:Muscle Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D014157:Transcription Factors