November 26, 2007
When reading through the scientific literature, it’s easy to encounter the long, anatomically descriptive names of adult stem cells. These include tongue twisters such as bone marrow-derived mesenchymal stem cells and multi-potent adult progenitor cells. And yet, as official as these names sound, they remain only partial addresses. Missing are the next lines of information that contain the descriptive molecular markers that would allow scientists to identify the cells prospectively and, like a street address, indicate where they reside in their tissues of origin. The reason is scientists in search of adult stem cells now generally first extract tissue from a predetermined place in the body, culture the various cells in the sample, and retrospectively identify the colonies of adult progenitor cells that appear. But in the September issue of the journal Nature Biotechnology, an NIDCR grantee and colleagues report for the first time that they have prospectively identified myogenic, or muscle-forming, endothelial cells in human skeletal muscle. The cells, which co-express myogenic and endothelial protein markers, differentiated into muscle, bone, or cartilage-forming cell lineages. Importantly, the scientists found they could use these cells to regenerate muscle fibers in mice that had skeletal muscle injuries. The cells also proved to be quite amenable to biotechnological processing. As the scientists concluded, “These properties [ease of biotechnological processing], together with their high muscle-regeneration ability, suggest that such autologous progenitors could be envisioned as a therapy for muscle diseases.”