Restricted differentiation potential of progenitor cell populations obtained from the equine superficial digital flexor tendon (SDFT)

• Published in: Journal of orthopaedic research Vol. 33; no. 6; pp. 849 - 858
• Main Authors: Williamson, Kate Ann, Lee, Katie Joanna, Humphreys, William James Edward, Comerford, Eithne Josephine Veronica, Clegg, Peter David, Canty-Laird, Elizabeth Gail
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01-06-2015; John Wiley and Sons Inc
• Subjects: Adult Stem Cells - physiology; Animals; Cell Adhesion; Cell Differentiation; Cell Separation; Cells, Cultured; differentiation; equine; Fibronectins; Horses; progenitor; stem; tendon; Tendons - cytology; Wound Healing; progenitor; tendon; differentiation; equine; stem
• ISSN: 0736-0266; 1554-527X
• DOI: 10.1002/jor.22891

ABSTRACT
The aim of this study was to characterize stem and progenitor cell populations from the equine superficial digital flexor tendon, an energy‐storing tendon with similarities to the human Achilles tendon, which is frequently injured. Using published methods for the isolation of tendon‐derived stem/progenitor cells by low‐density plating we found that isolated cells possessed clonogenicity but were unable to fully differentiate towards mesenchymal lineages using trilineage differentiation assays. In particular, adipogenic differentiation appeared to be restricted, as assessed by Oil Red O staining of stem/progenitor cells cultured in adipogenic medium. We then assessed whether differential adhesion to fibronectin substrates could be used to isolate a population of cells with broader differentiation potential. However we found little difference in the stem and tenogenic gene expression profile of these cells as compared to tenocytes, although the expression of thrombospondin‐4 was significantly reduced in hypoxic conditions. Tendon‐derived stem/progenitor cells isolated by differential adhesion to fibronectin had a similar differentiation potential to cells isolated by low density plating, and when grown in either normoxic or hypoxic conditions. In summary, we have found a restricted differentiation potential of cells isolated from the equine superficial digital flexor tendon despite evidence for stem/progenitor‐like characteristics. © 2015 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 33:849–858, 2015.