title: Comparative analysis of rat mesenchymal stem cells derived from slow and fast skeletal muscle in vitro.
abstract: OBJECTIVE
  Skeletal muscle comprises different kinds of muscle fibres that can be classified as slow and fast fibres. The purpose of this study was to compare the yield, proliferation, and multi-potentiality of rat mesenchymal stem cells (MSCs) from the tibialis anterior (TA; fast muscle) and soleus (SO; slow muscle) in vitro.
  
  
  METHODS
  The TA and SO muscles were harvested, and isolated cells were plated. After two hours, the cells were washed extensively to remove any cell that did not adhere to the cell culture plate. The adherent cells, namely MSCs, were then cultured. Both types of MSCs were differentiated toward the osteogenic, chondrogenic and adipogenic lineages using lineage specific induction factors.
  
  
  RESULTS
  The colony-forming unit fibroblast (CFU-F) assay revealed that the SO contained significantly higher quantities of MSCs than the TA. The self-renewal capacity of MSCs derived from the TA was significantly higher at later passages (passage 9-11). Both types of MSCs exhibited similar cell surface antigens to bone marrow (BM)-derived MSCs and were positive for CD29, CD44, and CD90 and negative for CD11b, CD34, and CD45. TA-derived MSCs were superior in terms of osteogenic differentiation capacity, but there was no significant difference in chondrogenic and adipogenic differentiation capacity.
  
  
  CONCLUSIONS
  Our results demonstrated significant differences in the properties of muscle-derived MSCs from different muscle types (i.e. fast or slow muscles). The greater expandability and osteogenic differentiation ability of TA-derived MSCs suggests that fast muscle may be a better source for generating large numbers of MSCs for bone regeneration.
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, Japan, 650-0017.
authors.forename: Etsuko
authors.initials: E
authors.lastname: Okumachi
authors.forename: Sang Yang
authors.initials: SY
authors.lastname: Lee
authors.forename: Takahiro
authors.initials: T
authors.lastname: Niikura
authors.forename: Takashi
authors.initials: T
authors.lastname: Iwakura
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Dogaki
authors.forename: Takahiro
authors.initials: T
authors.lastname: Waki
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Takahara
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ueha
authors.forename: Yoshitada
authors.initials: Y
authors.lastname: Sakai
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kuroda
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kurosaka
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000502:physiology*; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000502:physiology; D002469:Cell Separation; D003114:Colony-Forming Units Assay; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology; D018656:Muscle Fibers, Fast-Twitch / Q000166:cytology*; D018657:Muscle Fibers, Slow-Twitch / Q000166:cytology*; D018482:Muscle, Skeletal; D010012:Osteogenesis / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley