Project description:Numerous studies have been conducted to improve the supply of myogenic stem cells for patients with muscle disease, including Duchenne muscular dystrophy. Collecting muscle samples from patients in order to obtain myoblasts or satellite cells is very invasive. Thus, a new method for obtaining myogenic stem cells is required. Here, we established stably expandable induced myogenic stem cells (iMSCs) with defined factors. The iMSCs showed high expression levels of Pax7, Myf5, and MyoD. Also, the iMSCs differentiate into myotubes which are multinucleated fiber. Additionally, the iMSCs differentiated into myotubes, which are multinucleated fibers. We confirmed its myogenic differentiation capacity in mdx mice by detecting dystrophin-positive cells in iMSCs-injected TA muscles. The iMSCs showed higher proliferation capacity than MDSCs in both in vitro and vivo. This study suggests the possibility to apply directly converted expandable myogenic stem cells to muscle disease patients.
Project description:Skeletal muscle research is transitioning towards 3D tissue engineered in vitro models reproducing muscle’s native architecture and supporting measurement of functionality. Human induced pluripotent stem cells (hiPSCs) offer high yields of cells for differentiation. It has been difficult to differentiate high quality, pure 3D muscle tissues from hiPSCs that show contractile properties comparable to primary myoblast-derived tissues. Here, we present a transgene-free method for the generation of purified, expandable myogenic progenitors (MPs) from hiPSCs grown under feeder-free conditions. We defined a protocol with optimal hydrogel and medium conditions that allowed production of highly contractile 3D tissue engineered skeletal muscles with forces similar to primary myoblast-derived tissues. Gene expression and proteomic analysis between hiPSC-derived and primary myoblast-derived 3D tissues revealed a similar expression profile of proteins involved in myogenic differentiation and sarcomere function. The protocol should be generally applicable for the study of personalized human skeletal muscle tissue in health and disease.
