Fig. 1

Study design, donor groups, and tissue samples. The skeletal muscle and trabecular bone were collected from the hip joint of all donors. The cells were isolated from both of the tissues using collagenase digestion. An aliquot of freshly isolated cells was used for ex vivo analysis to determine cell viability and the mesenchymal fraction, using flow cytometry. The rest of the freshly isolated cells were culture-expanded to perform in vitro analyses, including the colony-forming unit fibroblast assay, growth kinetics, osteogenic, chondrogenic and adipogenic differentiation, immunophenotyping, senescence, and gene expression of several MSC markers