Researchers Discover Tendon Stem Cells

Stem cells are cells that can form many different types of cells in the body, such as muscle, brain, bone, and blood. They can divide and renew themselves over long periods of time. Scientists have studied ways that stem cells might be used to treat diseases like arthritis and Alzheimer's as well as injuries like burns and broken bones. Stem cells can be found in embryos but also in adults.

Until now, researchers have not been able to identify stem cells in tendons, and it was not known if tendon stem cells exist. Recently, researchers at the Carnegie Institution for Science discovered tendon stem cells for the first time. Tendon stem cells can form new tenocyte cells, which are the tendon cells that make new collagen. Given that tenocytes can become injured in tendinopathy, the ability for tendon stem cells to make new tenocytes could be as game changer.

Researchers found that stem cells and scar-tissue-forming cells both exist in the same space surrounding tendons, and both these types of cells respond to platelet-derived-growth-factor-A. If the tendon stem cells are altered to not respond to this growth factor, then only scar tissue forms in response to the growth factor. Researchers hope to find ways to help the stem cells outcompete the scar tissue cells by inhibiting the scar tissue response to the growth factor while enhancing the stem cell response to it.

A nice article summarizing this research, including an interesting photo of tendon cells, can be found on the Carnegie site. The researchers' original paper can be found in Nature Cell Biology.