Fig. 2

Exosomes derived from MS-BMDMs promote BMSCs osteogenesis in vitro. a Immunofluorescence images of the internalization of Dil-labelled MS-BMDM-EXOs in BMSCs after treatment for 12 h. MS-BMDM-EXOs and nuclei were stained with Dil (red) and DAPI (blue), respectively. Scale bar: 50 μm. b-f qRT‒PCR analysis of the mRNA expression of osteogenic genes and Western blotting of RUNX2 protein levels in BMSCs after treatment with PBS, BMDM-EXOs and MS-BMDM-EXOs (n = 3). g Relative intensity analysis of f (n = 3). h, i ALP staining and Alizarin red staining in BMSCs after treatment with PBS, BMDM-EXOs and MS-BMDM-EXOs. Scale bar: 100 µm. j Schematic illustration. k, l qRT‒PCR analysis of the mRNA expression of osteogenic genes and Western blotting of RUNX2 protein level in BMSCs after culture with conditioned medium from MS-BMDMs treated with GW4869 or DMSO as a control (n = 3). m Relative intensity analysis from l. n, o ALP staining and Alizarin red staining of BMSCs after culture with conditioned medium from MS-BMDMs treated with GW4869 or DMSO as a control. Scale bar: 100 μm. Data are shown as the mean ± SD. Two-tailed unpaired Student’s t test or one-way ANOVA followed by Tukey’s post hoc multiple comparisons were performed. *P < 0.05, **P < 0.01, ***P < 0.001