| Human skeletal muscle is an essential source of various cellular progenitors with potential therapeutic perspectives. Muscle-resident mesenchymal stromal cells (mrMSCs) are thought to be involved in the development of several regenerative disorders such as fatty degeneration, heterotopic ossification and fibrosis. Identifying the cell population responsible for these pathologies will help better understand the underlying mechanisms and lead to more efficient treatment. We first developed an isolation method and culture conditions for the proliferation and maintenance of the adherent fraction of human skeletal muscle derived cells. To further enrich the cell population as multipotent progenitors, we used fluorescent-activated cell sorting (FACS) and known mesenchymal stromal cell (MSC) markers. The enriched cell populations obtained were tested for their multipotent capabilities towards the osteogenic, adipogenic and chondrogenic lineages. The CD73+CD 105+CD90- subset of human skeletal muscle adherent cells displayed robust multipotence to all three lineages under the appropriate differentiation conditions. Clonal differentiation assays confirmed that all three lineages stem from a single multipotent progenitor. Furthermore, this cell subset was able to differentiate into brown adipocyte-like cells, expressing UCP1 at the RNA and protein levels following prolonged stimulation with rosiglitazone (ROS). This result suggests that this cell subset could also represent a human cell model for brown adipogenesis. The cell isolation and enrichment method presented in this thesis represent a novel technique to obtain human mrMSCs. This method holds great promise for future clinical applications with the enriched cell populations since they are expanded in a defined medium, which supports inter-laboratory reproducibility. Furthermore, the phenotypic markers chosen for the FACS isolation are well conserved amongst donors in the proposed conditions, limiting donor-to-donor variability.;Keywords: Brown adipogenesis, Fluorescent-activated cell sorting, Human skeletal muscle, Mesenchymal stromal cells, Multipotency, Regenerative disorders. |
