Insights into auto-transplantation - The unexpected discovery of transdifferentiation systems in bone marrow stromal cells and its application

Many kinds of cells, including embryonic stem cells and tissue stem cells, have been considered candidates for cell transplantation therapy for muscle-degenerative diseases. Bone marrow stromal cells (MSCs) also have great potential as therapeutic agents since they are easily isolated and can be expanded from patients without serious ethical or technical problems. Recently, new methods for the highly efficient and specific induction of functional skeletal muscle cells have been found in MSCs. Induced cells differentiate into muscle fibers upon transplantation into degenerated muscles of rats and mdx-nude mice. Furthermore, the induced population contained Pax7-positive cells that contribute to subsequent regeneration of muscle upon repetitive damage without additional transplantation of cells. Here I describe the discovery of these induction systems and focus on the potential use of MSC-derived cells for "auto-cell transplantation therapy" in muscle-degenerative diseases.