Maintenance of Tendon Stem/Progenitor Cells in Culture.

Tendon stem/progenitor cells (TSCs) are tendon-specific adult stem cells, which play crucial roles in tendon homeostasis, repair or regeneration once tendons are injured. Additionally, their pathological role in the development of tendinopathy in response to excessive mechanical loading placed on the tendon is also implicated. Similar to other adult stem cells, TSCs also exhibit universal characteristics of stem cells including colony formation in culture, self-renewal and multidifferentiation potential. Nevertheless, once TSCs are isolated from tendinous tissues and cultured in vitro, they may quickly lose stemness by undergoing differentiation. To maintain and prolong the stemness of TSCs in culture, we have developed two effective methods, namely culturing TSCs in hypoxic condition, or in growth media supplemented with low levels of PGE2. Here we present these methods in detail, along with the detailed description of the procedures to isolate TSCs from tendon samples and to culture them in vitro.