Allogeneic bone marrow-derived mesenchymal stromal cells promote the regeneration of injured skeletal muscle without differentiation into myofibers.
Half-stratum laceration was performed on the tibialis anterior muscle of Sprague-Dawley (SD) rats as a skeletal muscle injury model. Bone marrow-derived mesenchymal stromal cells (BMMSCs), which were derived from enhanced green fluorescent protein (GFP) transgenic SD rats, were transplanted into the injured site. Tensile strength produced by nerve stimulation was measured for functional evaluation before sacrifice. Specimens of the tibialis anterior muscles were stained with hematoxylin and eosin, and immunohistochemically stained for histological evaluation. Our results showed that transplanted BMMSCs promoted maturation of myofibers histologically and made the injured muscle acquire almost normal muscle power functionally by 1 month after transplantation. However, the results of immunohistochemical staining could not prove that transplanted BMMSCs differentiated into or fused to skeletal myofibers, although it showed that transplanted BMMSCs seemed to differentiate into muscle precursor cells. Therefore, our results indicated that BMMSCs contributed to the regeneration of skeletal muscle by mechanisms other than fusion to myofibers after differentiation.
Natsu
Koji
K
Department of Orthopaedic Surgery, Programs for Applied Biomedicine, Division of Clinical Medical Science, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8551, Japan. natchi@hiroshima-u.ac.jp
Ochi
Mitsuo
M
Mochizuki
Yu
Y
Hachisuka
Hiroki
H
Yanada
Shinobu
S
Yasunaga
Yuji
Y
D000818:Animals; D001854:Bone Marrow Cells / Q000473:pathology; D016026:Bone Marrow Transplantation / Q000379:methods / Q000473:pathology; D002454:Cell Differentiation; D002478:Cells, Cultured; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods*; D059630:Mesenchymal Stem Cells / Q000473:pathology*; D009119:Muscle Contraction; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D018482:Muscle, Skeletal / Q000293:injuries* / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012038:Regeneration / Q000502:physiology; D017154:Stromal Cells / Q000473:pathology / Q000637:transplantation; D014184:Transplantation, Homologous; D014945:Wound Healing / Q000502:physiology*; D014950:Wounds, Penetrating / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*