title: Vitamin D receptor gene silencing effects on differentiation of myogenic cell lines.
abstract: BACKGROUND
  The active form of vitamin D (1,25-dihydroxy-vitamin D3) is known to increase fast-type myosin heavy chain expression in differentiated myogenic cell lines. The mechanisms for this effect are not fully understood. The aim of this study was to determine the role of signals transmitted through the vitamin D receptor (VDR) during differentiation of myoblasts.
  
  
  METHODS
  Electroporation was used to introduce VDR siRNA molecules into C2C12 and G8 murine myoblast cell lines. Gene and protein expression profiles of VDR-gene silenced cells were analyzed in vitro.
  
  
  RESULTS
  Suppressing VDR expression by RNA interference resulted in inhibition of myogenic differentiation of C2C12 and G8 cell lines at both mRNA and protein levels.
  
  
  CONCLUSIONS
  Our results suggest that myoblasts require signals transmitted through VDR for differentiation into myocytes and emphasize the importance of VDR expression in skeletal muscles for maintaining muscle volume in the elderly.
authors.affiliation: Department of Orthopaedic Surgery, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Japan, 980-8574.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Tanaka
authors.forename: Koshi N
authors.initials: KN
authors.lastname: Kishimoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Okuno
authors.forename: Hideo
authors.initials: H
authors.lastname: Saito
authors.forename: Eiji
authors.initials: E
authors.lastname: Itoi
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D020868:Gene Silencing; D051379:Mice; D032342:Muscle Cells / Q000378:metabolism / Q000502:physiology; D024510:Muscle Development / Q000235:genetics / Q000502:physiology*; D032446:Myoblasts / Q000378:metabolism*; D018008:Myogenin / Q000235:genetics / Q000378:metabolism; D018995:Myosin Heavy Chains / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering; D018167:Receptors, Calcitriol / Q000235:genetics / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology*
chemical_list: C503801:Myog protein, mouse; D018008:Myogenin; D034741:RNA, Small Interfering; D018167:Receptors, Calcitriol; D018995:Myosin Heavy Chains
keywords: C2C12; G8; VDR; gene silencing; myoblasts; myosin heavy chain