Fig. 4. The enhanced osteogenic differentiation of MSCs due to the supplement of IL-37 was partially rescued by the presence of PI3K/AKT signaling inhibitor.

a The increased mRNA levels of COL1A1, RUNX2, and OCN induced by IL-37 treatment (100 ng/ml) were significantly decreased following the addition of 20 μM LY294002 for 3 days; b Western blot analyses on day 3 of osteogenesis showed that the level of p-AKT was significantly decreased compared with the level in IL-37 (100 ng/ml) treated BMSCs without the inhibitor; c Relative quantitative analysis of western blot analyses; d, e Immunofluorescence staining of RUNX2 and its relative quantitative analysis, scale bar = 100 μm; f, g Immunofluorescence staining of COL1A1 and its relative quantitative analysis, scale bar = 100 μm; h Results of ALP staining, scale bar = 500 μm; i Results of relative ALP activity; j, k Results of ARS and its relative quantitative analysis, scale bar = 500 μm. *P < 0.05 vs. control group; ^#P < 0.05 vs. IL-37 group