Fig. 4

IPA generated networks derived from the proteins with different abundance in the chondrogenic, tenogenic and osteogenic constructs derived from young and old MSCs. IPA identified that lipid metabolism signalling pathways were predominant in chondrogenic constructs (a). In tenogenic constructs, signalling pathways were enriched for glucose metabolic processes (b). In osteogenic constructs, the principle signalling pathway was mitochondrial dysfunction (c). One of the principle functions associated with the DE proteins in tenogenic constructs was also protein metabolism (d). Green nodes, greater protein abundance in young; red nodes, greater protein abundance in old; white nodes, proteins not differentially abundant between young and old. Intensity of colour is related to higher fold-change. Key to the main features in the networks is shown