RESUMO
BACKGROUND: Skeletal muscle defect is a major concern of plastic and orthopedic surgeons due to poor regenerative capability of skeletal myocytes and limited clinical treatment. Recently, cell therapy and skeletal muscle engineering based on adipose-derived stem cells (ADSCs) open a new era for skeletal muscle injury repair, which attributes to merits of ADSCs including sufficiency, easy harvest, high yield, strong proliferation and paracrine capability, as well as differentiation potential towards skeletal myoblasts under specific induction. OBJECTIVE: To summarize the process of ADSCs' differentiation towards skeletal myoblasts, to analyze factors that may affect myogenic differentiation of ADSCs and their underlying mechanism, and to discuss the oncological safety of ADSC therapy and limits for clinical application. METHODS: Search in PubMed using the following formula ((myogenic[Title]) OR myogenesis[Title]) AND adipose stem cell[MeSH Terms]) and in SinoMed using ((("adipose tissue"[Title]) AND "Stem cell"[Title]) AND "myo-"[Title]) was done on June 10th, 2017. References related to ADSCs' myogenic differentiation or skeletal muscle repair were included, whereas repeated references were excluded. RESULTS AND CONCLUSION: Forty-seven references in PubMed were selected. Within them, 26 were published in recent 5 years. Forty-seven references in SinoMed met the criteria; however 34 of them were about ADSCs' differentiation towards myocardial cells and 6 were about ADSCs' differentiation towards smooth muscle cells. Eventually, 50 references were included. ADSCs' differentiation towards skeletal myoblasts under specific induction is a complicated process involving the interactions of varieties of genes, proteins and signal pathways.Besides the traditional in vitro chemical induction,conditioned medium or co-culture with myocytes can also facilitate ADSCs' differentiation towards skeletal myoblasts. Chemicals, biomechanics, myogenic regulatory factors, cytokines, growth factors, microRNAs and lncRNA have effects on ADSCs myogenic differentiation. ADSCs can promote the repair of morphology and function of skeletal muscle through direct differentiation or indirect paracrine of cytokines, regulating inflammatory response, suppressing apoptosis, accelerating angiogenesis, and recruiting endogenous stem cells. The future study concerning skeletal muscle repair is expected to address the construction of tissue-engineered muscle by combining various cytokines and growth factors with three-dimensional scaffolds to promote ADSCs' proliferation and differentiation.