Lee, K.J., et al. Identification and characterisation of canine ligament progenitor cells and their extracellular matrix niche. Journal of Proteome Research. 22/1/2019.

Ligaments are prone to injury and degeneration in humans and animals, however the healing potential of ligament is poor and current treatment options ineffective. Stem cell-based therapies hold potential for treatment of ligament injuries. This study aimed to characterise a ligament progenitor cell (LPC) population and to identify specific niche components which could promote the survival and function of LPCs. LPCs were isolated from canine cranial cruciate ligament and characterised for clonogenicity, multipotency and marker expression. The extracellular matrix (ECM) composition was characterised by the novel application of a metabolic labelling and mass spectrometry technique. LPCs demonstrated clonogenicity, multipotency and stem cell marker expression. A number of different collagens, glycoproteins and proteoglycans were identified in the LPC niche using proteomics. Metabolic labelling of cells demonstrated unique turnover profiles for distinct ECM protein groups, indicating the importance of certain niche components for LPC survival and function. The newly synthesised niche components identified in this study could be exploited to aid identification of LPCs and to promote their survival and function for potential ligament repair strategies.