Résumé :
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Duchenne muscular dystrophy (DMD) is the most frequent dystrophy by affecting 1 male on 3500 all around the world. Cellular therapy is one of the promising potential treatments for this disease although it faces some problems. Growth factors, such as the insulin like growth factor-1, are able to increase or decrease the proliferation, differentiation, migration and survival of cells. The mechano growth factor (MGF) is an IGF-1 isoform produced after a mechanical stress. The E peptide of MGF has been shown to play a role in the muscle physiology. Here, we use the predicted 24 amino acids (MGF-ct24E) from the E peptide of MGF to investigate its effects on the engraftment of human and mouse muscular precursor cells (MPCs) in the Tibialis anterior of SCID and mdx mice. The MGF-ct24E has been shown to modulate the proliferation and differentiation of C2C12 myoblasts. Our results showed, in vitro, the enhanced proliferation of MPCs treated with this peptide which could be due to the delayed fusion also observed. Moreover, this mechanism passes through another receptor than the IGF-1 receptor. In contrast with the IGF-1, the MGF-ct24E had no effect on the survival of human MPCs. In vivo, the pre-treatment and co-injection of the peptide with the MPCs showed no amelioration on the graft success established by the percentage of dystrophin positive fibers. However, when injected systemically or intra-muscularly, an improvement up to 1.6 fold was observed on the graft success. Together, those results demonstrate an interesting and non-invasive way to improve the engraftment of MPCs in DMD patients.
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