Fig. 3. Exosomes in a co-culture system of IECs treated with HO-1/BMMSCs (HBM-exo) have a better protective effect than BM-exo on IEC-6s injured by inflammation.

a–c The extracted exosomes were identified. After the exosomes were extracted from BMMSCs, they were observed to be vesicular under transmission electron microscope (a) and were detected using Nanoparticle tracking analysis (b, dilution factor: 600). Western blotting confirmed the positive expression of CD63, TSG101, and CD9 as exosome marker proteins and the negative expression of Calnexin (c). d The morphology of the IECs in each group was observed under a light microscope. e The relative cell viability of each group was detected (fold change relative to the Mock group, n = 5). f Annexin V-FITC/PI-PE was used to detect the proportion of early apoptotic cells in each group (n = 4). g, h The proportion of TUNEL + cells (shown by the white arrows) in each group (n = 3). i Labeling by immunofluorescence for the ZO-1 protein in each group. j The relative levels of (cleaved) caspase-3, BAX, BCL2, and ZO-1 in each group was detected using western blotting (n = 3). *P < 0.05. BAX B-cell lymphoma-2 associated X, apoptosis regulator; BCL2, B-cell lymphoma-2 apoptosis regulator; BMMSCs Bone marrow mesenchymal stem cells; BM-exo BMMSCs co-culture system exosomes; CD63 lysosomal membrane-associated glycoprotein 3; CD9 CD9 molecule; Exo exosomes; FITC fluorescein isothiocyanate; HO-1 heme oxygenase-1; HBM-exo HO-1/BMMSCs co-culture system exosomes; IECs intestinal epithelial cells; PE phycoerythrin; PI propidium iodide; TNF-α tumor necrosis factor alpha; TNF-α-exo tumor necrosis factor alpha-treated IEC-6s system exosomes; TSG 101 tumor susceptibility 101; TUNEL terminal deoxynucleotidyl transferase nick-end-labeling; ZO-1 Zona Occludens 1.