title: A vitamin D analogue, eldecalcitol, enhances expression of fast myosin heavy chain subtypes in differentiated C2C12 myoblasts.
abstract: BACKGROUND
  Several lines of evidence indicate that the active form of vitamin D has an anabolic effect on skeletal muscle. Eldecalcitol, an analogue of the active form of vitamin D, has the potential to increase bone density and decrease fracture risk. The objective of this study was to investigate the effect of eldecalcitol in C2C12 myogenic cells.
  
  
  METHODS
  C2C12 cells were grown to confluency and the culture medium was replaced with low-glucose DMEM containing 2% horse serum. Eldecalcitol was added at a concentration of 1, 10 or 100 nM. Gene expression profiles of vitamin D receptor (VDR), MyoD, IGF-1, neonatal myosin heavy chain (MHC), and the fast MHC subtypes Ia, IIa, IIb and IId/x were analyzed by quantitative RT-PCR. Protein expression of MHC subtypes was evaluated by western blotting and immunostaining.
  
  
  RESULTS
  Eldecalcitol upregulated gene expression of VDR, MyoD and IGF-1. Incubation with eldecalcitol in the absence of serum followed by the addition of serum after 1 h was associated with greater increases in the expression of these genes compared with co-incubation with eldecalcitol and serum. Gene expression of MHC subtypes IIa, IIb and IId/x was significantly increased by eldecalcitol. Protein expression of fast MHC subtypes was significantly increased by eldecalcitol at 1 and 10 nM.
  
  
  CONCLUSIONS
  Similar to the active form of vitamin D, eldecalcitol had an anabolic effect on fast MHC subtypes. Taking into account its pharmacokinetic profile, eldecalcitol is expected to be beneficial for the maintenance and improvement of muscle function in elderly individuals.
authors.affiliation: Department of Orthopaedic Surgery, Tohoku University Graduate School of Medicine, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Saito
authors.affiliation: Department of Orthopaedic Surgery, Tohoku University Graduate School of Medicine, Japan.
authors.forename: Koshi N
authors.initials: KN
authors.lastname: Kishimoto
authors.affiliation: Department of Orthopaedic Surgery, Tohoku University Graduate School of Medicine, Japan. Electronic address: yu-mori@med.tohoku.ac.jp.
authors.forename: Yu
authors.initials: Y
authors.lastname: Mori
authors.affiliation: Department of Orthopaedic Surgery, Tohoku University Graduate School of Medicine, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Okuno
authors.affiliation: Department of Orthopaedic Surgery, Tohoku University Graduate School of Medicine, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Tanaka
authors.affiliation: Department of Orthopaedic Surgery, Tohoku University Graduate School of Medicine, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Itoi
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D051379:Mice; D032446:Myoblasts / Q000166:cytology / Q000187:drug effects*; D018995:Myosin Heavy Chains / Q000187:drug effects*; D012313:RNA / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction; D018167:Receptors, Calcitriol / Q000187:drug effects / Q000235:genetics*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D018167:Receptors, Calcitriol; D014807:Vitamin D; D012313:RNA; D018995:Myosin Heavy Chains; C547512:eldecalcitol