Jt. Williams et al., Cells isolated from adult human skeletal muscle capable of differentiatinginto multiple mesodermal phenotypes, AM SURG, 65(1), 1999, pp. 22-26
Wound healing is the response of tissue to injury that results in scar form
ation. Tissue regeneration would be a more ideal response. Previously, we h
ave isolated a population of cells from avian, rodent, and rabbit skeletal
muscle capable of differentiating into multiple mesodermal phenotypes. The
present experiments were designed to determine whether a similar population
of cells exist in human skeletal muscle. Separate cell preparations from s
keletal muscle on an amputated leg of a 75-year-old female and the pectoral
is muscle of a 27-year-old male were enzymatically dissociated and cultured
to confluence in Eagle's minimal essential medium with 10 per cent presele
cted horse serum, then trypsinized, filtered, and slowly frozen in 7.5 per
cent dimethylsulfoxide to -80 degrees C. The cells were thawed and plated w
ith the same media plus dexamethasone (a nonspecific differentiation agent)
at 10(-10)-10(-6) M concentrations for up to 6 weeks. Immunological and hi
stochemical staining assays were performed. Phenotypes observed included st
em cells with typical stellate morphology (control), skeletal myotubes (ant
i-myosin), smooth muscle (anti-a-actin), bone (von Kossa stain), cartilage
(Alcec blue), and fat (Sudan black B). These experiments establish the exis
tence of a population of mesenchymal stem cells in human skeletal muscle ca
pable of differentiating into multiple mesodermal phenotypes. The possibili
ty exists of manipulating the mesenchymal stem cells to achieve appropriate
regeneration of mesenchymal tissues in the injured patient.