Fig. 4

Potential ligand–receptor interactions analysis in HBB high-expressing and HBB low-expressing chondrocytes. A-D. The quantity and intensity of interaction between different chondrocytes subpopulations and high outgoing and incoming signaling pattern in different chondrocytes subpopulations in HBB high-expressing chondrocytes (A-B) and HBB low-expressing (C-D) chondrocytes. E-F. The ligand–receptor pairs exhibit the major interaction pathways between FC (E) or ProC (F) chondrocyte subpopulation and any one of the chondrocyte subpopulations in HBB high-expressing chondrocytes. G-I. The expression of representative signaling pathways in HBB low-expressing and HBB high-expressing chondrocytes. The number of SPP1 associated differentially expressed genes (DEGs) is high HBB high-expressing chondrocytes (H) and HBB low-expressing chondrocytes (I), and in the comparison of HBB high-expressing and HBB low-expressing chondrocytes (G). J. Heatmap illustrating the roles of different cell subpopulations in the expression of the SPP1 associated pathway in HBB high-expressing chondrocytes, and SPP1 associated signals were mainly generated by RegC and received by all other kind of cell subpopulation