Fig. 9
Coordinated alterations occur across the different subpopulations upon ageing. Correlation matrix (Spearman) for extracellular protein–ligand receptor pairs at the interface between MSCs and all other cell populations (see Methods). MSC ligands (L) and MSC receptors (R) altered upon ageing (p value < 0.1, Spearman's correlation) on the y-axis have at least one correlation value with altered receptors (R) or ligands (L) quantified in the other cell populations with a p value < 0.1, Spearman's correlation. The colour indicates positive or negative correlation and the size of the circle is reciprocal to the associated p value. Correlation coefficients with p values ≥ 0.1 are depicted as transparent. Unsupervised clustering using Euclidean distances and the complete clustering method was performed on both axes
