Adult Stem Cells Isolated in Tendon

Tendon contains a small subset of previously unknown adult stem cells. The finding of scientists at the National Institute of Dental and Craniofacial Research (NIDCR) and their colleagues, published online in the journal Nature Medicine, points to a natural source of tendon-producing cells in adults. With further research, these cells, called tendon stem/progenitor cells (TSPCs), one day could help to mend torn or degenerating tendons that are slow to heal. This also brings to light an unexpected biochemical habitat, or niche, that harbors stem cells. The cells are embedded between layers of extracellular matrix, the chain-like coils of protein that give tendon its elasticity and contain relatively few cells or blood vessels. To date, most known adult stem cells occupy cell-rich environments with a ready source of nutrients. Understanding of tendon biology is very much a work in progress. The TSPCs provide a needed early entry point to better understand its developmental and regenerative dynamics. It is reasonable to say that the TSPCs one day could have an important role therapeutically. Torn tendons are much slower to heal than bone injuries, in part because tendons are so blood-vessel poor, which inhibits the regenerative process. Using stem cells to create new tendon gets around that problem. To reach that point, however, a lot of biology and uncertainty will need to be worked out. (Source: NIDCR Web site, News Releases, accessed October 8, 2007)