title: Upregulation of interleukin-1β/transforming growth factor-β1 and hypoxia relate to molecular mechanisms underlying immobilization-induced muscle contracture.
abstract: BACKGROUND
  In this study we investigated the molecular mechanism underlying muscle contracture in rats.
  
  
  METHODS
  The rats were divided into immobilization and control groups, and soleus muscles of the right and left sides were selected for analyses.
  
  
  RESULTS
  The levels of CD11b and α-SMA protein, IL-1β, and TGF-β1 mRNA, and type I and III collagen protein and mRNA were significantly greater in the immobilization group than in the control group at all time-points. HIF-1α mRNA levels were significantly higher in the immobilization group at 4 weeks. Moreover, HIF-1α, α-SMA, and type I collagen levels were significantly higher at 4 weeks than at 1 and 2 weeks in the immobilization group.
  
  
  CONCLUSIONS
  In the early stages of immobilization, upregulation of IL-1β/TGF-β1 via macrophages may promote fibroblast differentiation that could affect muscle contracture. The soleus muscle became hypoxic in the later stages of immobilization, suggesting that hypoxia influences the progression of muscle contracture.
authors: Department of Locomotive Rehabilitation Science, Unit of Rehabilitation Sciences, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto 1-7-1, Nagasaki, 852-8520, Japan.|Department of Rehabilitation, Nagasaki University Hospital, Nagasaki, Japan.
authors: Yuichiro
authors: Y
authors: Honda
authors: Department of Physical Therapy Science, Unit of Physical and Occupational Therapy Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors: Junya
authors: J
authors: Sakamoto
authors: Department of Physical Therapy Science, Unit of Physical and Occupational Therapy Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors: Jiro
authors: J
authors: Nakano
authors: Department of Locomotive Rehabilitation Science, Unit of Rehabilitation Sciences, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto 1-7-1, Nagasaki, 852-8520, Japan.
authors: Hideki
authors: H
authors: Kataoka
authors: Department of Locomotive Rehabilitation Science, Unit of Rehabilitation Sciences, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto 1-7-1, Nagasaki, 852-8520, Japan.|Department of Rehabilitation, Nagasaki University Hospital, Nagasaki, Japan.
authors: Ryo
authors: R
authors: Sasabe
authors: Department of Locomotive Rehabilitation Science, Unit of Rehabilitation Sciences, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto 1-7-1, Nagasaki, 852-8520, Japan.
authors: Kyo
authors: K
authors: Goto
authors: Department of Physical Therapy Science, Unit of Physical and Occupational Therapy Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors: Miho
authors: M
authors: Tanaka
authors: Department of Locomotive Rehabilitation Science, Unit of Rehabilitation Sciences, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto 1-7-1, Nagasaki, 852-8520, Japan.
authors: Tomoki
authors: T
authors: Origuchi
authors: Department of Locomotive Rehabilitation Science, Unit of Rehabilitation Sciences, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto 1-7-1, Nagasaki, 852-8520, Japan.
authors: Toshiro
authors: T
authors: Yoshimura
authors: Department of Locomotive Rehabilitation Science, Unit of Rehabilitation Sciences, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto 1-7-1, Nagasaki, 852-8520, Japan.
authors: Minoru
authors: M
authors: Okita
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D039481:CD11b Antigen / Q000378:metabolism; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D024061:Collagen Type III / Q000235:genetics / Q000378:metabolism; D003286:Contracture / Q000209:etiology / Q000378:metabolism*; D005786:Gene Expression Regulation; D000860:Hypoxia / Q000235:genetics* / Q000378:metabolism; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics; D007103:Immobilization / Q000009:adverse effects; D053583:Interleukin-1beta / Q000235:genetics*; D018482:Muscle, Skeletal / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D053773:Transforming Growth Factor beta1 / Q000235:genetics*; D015854:Up-Regulation
chemical_list: D000199:Actins; D039481:CD11b Antigen; D024042:Collagen Type I; D024061:Collagen Type III; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D053583:Interleukin-1beta; D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1; C497444:Hif1a protein, rat; C000594089:IL1B protein, rat; C508962:Tgfb1 protein, rat; C498862:Acta2 protein, rat
keywords: IL-1β; TGF-β1; fibrosis; hypoxia; muscle contracture