Fig. 4

pOC-ABs and mOC-ABs inherit distinct biological functions from their parental cells. a Schematic diagram of the AB engulfment assay. Representative confocal micrographs showing cell tracker CM-DiI-labeled (b) EPCs or (c) MSCs (red) incubated with Annexin-V/FITC-labeled ABs (green). The merged images are shown in the left panel. The white arrows indicate ABs engulfed by recipient cells. The bar represents 10 μm. d EPC viability was assessed at 1, 3, and 7 days after treatment with different ABs. “Vehicle” represents EPCs cultured with complete medium. e Tube formation assay of EPCs cultured with ABs for 6 h. Representative images (left panel) and quantification analysis of the calculated tube lengths (right panel) are shown. The bar represents 100 μm, n = 5. f The levels of phosphorylated PI3K and AKT in EPCs were determined by western blot analysis. g RT-qPCR analysis of Pecam1, ANG-1, and Kdr expression in EPCs treated with medium containing different ABs. h Representative images of ALP staining and quantification of ALP activity. “Vehicle” indicates MSCs cultured with complete medium, n = 5. i Representative images of ARS staining and quantitative analysis of calcium deposits in MSCs. “Vehicle” indicates MSCs cultured with complete medium, n = 5. j RT-qPCR analysis of Alpl, Osx, Runx2, and Col1a1 expression in MSCs cultured with medium containing different ABs. k Western blots of the osteogenic markers Collagen I and RUNX2 in MSCs cultured with ABs. The data in the figures are presented as the average ± SD values. Statistically significant differences between the treatment and control groups are indicated as * (P < 0.05) or ** (P < 0.01)