Myogenesis of Porcine Muscle Satellite Cells by Extracellular Matrix From Fibrotic Adipose Tissue-Derived Mesenchymal Stem Cells

Cultivated meat relies on the production of muscle tissue using cell culture techniques. Myogenesis is a cellular differentiation process in which muscle satellite cells (SC) transform into myoblasts, or myotubes. The extracellular matrix (ECM) plays a pivotal role in meat quality, myogenesis, SC proliferation, and muscle tissue development to replicate meat texture. Because fibrotic differentiation and ECM are involved in the myogenic process, we aimed to induce myogenesis in SC using fibrotic differentiation of adipose tissue-derived mesenchymal stem cells (ADSC). ADSC, fibroblasts (FC), and SC were isolated from the back fat, ear margin tissues, and femur muscle tissues, respectively, of a 1-year-old Berkshire piglet. ADSC were treated with connective tissue growth factor (CTGF; 0, 12.5, 25, or 50 ng/mL) for 72 h to induce fibrotic differentiation. Conditioned media from differentiated ADSC and FC were prepared and labeled CA-CM and F-CM, respectively. SC were exposed to CA-CM or F-CM to assess their effects on myogenesis. The results demonstrated α-smooth muscle actin and collagen I as the optimal markers for assessing fibrotic differentiation in ADSC. CTGF significantly elevated both mRNA and protein expression of α-smooth muscle actin and collagen I (P < 0.05), suggesting that CTGF acts as an inducer of fibrotic differentiation in ADSC. Moreover, CTGF elevated the expression of ECM components (laminin, fibronectin, and collagen I) in ADSC (P < 0.05). mRNA expression of myogenesis-related genes (MyoG, MyoD, Myf5, and Myf6) increased in SC exposed to both CA-CM and F-CM (P < 0.05). Our data revealed that fibrotic differentiation of ADSC increased ECM production, and ECM-containing conditioned medium induced myogenesis in SC. These findings indicate that ECM-containing conditioned medium is a good option for enhancing myogenesis in SC, with potential implications for cultivated meat production.