Fig. 2

GPNMB exerted a pro-senescence effect on BMMSCs (A) MS analysis of m-MSCs from young and D-Gal groups (schematic). (B) Heatmap of differentially expressed proteins (DEPs) in m-MSCs derived from young and D-Gal groups (fold change > 1.5 or < 0.67; p < 0.05). Red: upregulation. Blue: downregulation. (C) Volcano plot of DEPs. Log10 p-value is plotted against log2 value. (D) PCA analysis. (E) KEGG pathway analysis. (F) LC-MS analysis of GPNMB expression. (G) Western blotting analysis and quantification of GPNMB expression in m-MSCs from young and D-Gal groups. (H) Confocal microscopic analysis of LEPR (red) and GPNMB (green) expression in BM of young group, D-Gal group and ageing group as above. (I) GPNMB expression in MSC-T and MSC-T/OEG cells. (J) qRT-PCR analysis. (K) Western blotting analysis of senescence markers in MSC-T and MSC-T/OEG cells. (L) GPNMB expression in MSC-T, MSC-T/SHG1 and MSC-T/SHG2 cells. (M) qRT-PCR analysis. (N) Western blotting analysis of senescence markers in MSC-T and MSC-T/SHG2 cells. (O) Representative image of SA-β-gal staining and quantification of the percentage of SA-β-gal-positive cells in MSC-T and MSC-T/OEG cells. (P) Representative image of SA-β-gal staining and quantification of the percentage of SA-β-gal-positive cells in MSC-T and MSC-T/SHG2 cells. (Q) Apoptosis of MSC-T, MSC-T/vec, MSC-T/OEG and MSC-T/SHG cells. MSC-T/vec cells were used as the empty vector control group