Résumé :
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Cell therapy represents a valid tool for tissue replacement, in particular in the contest of muscle dystrophies or structural defects. According to recent studies, satellite cells (SCs) seem to be divided into two subpopulations: one of committed muscle precursors and one of cells with more stem-like properties. This distinction correlates to both diversity in markers expression and differentiation potential.In this study, through single fiber selection, two subpopulations of SCs obtained from rat flexor digitorum brevis and extensor digitalis longus muscles, were distinguished based on both different proliferative and differentiative capacities. Quantitative analyses showed that there is an almost fixed proportion of SCs that possess a great proliferative potential, and that spontaneously give rise to adipocytes in culture. Immunofluorescence and PCR analyses showed that while initially SCs are homogenously positive for early myogenic markers, pluripotent clones lose in culture myogenic properties and form lipid droplets in cytoplasm, becoming adipocytes.A deeper investigation concerning metabolic processes was performed measuring NaDH redox state, membrane potential, uptake and intake of Ca2+ revealing that these two subpopulations of SCs have different metabolic properties. In particular, we proved that the high proliferative clone had a more glycolytic metabolism compared to the low proliferative clone.These observations could be relevant in muscle regeneration therapies. Selection of satellite cells by their proliferative ability could have implication in their in vivo regeneration potential
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