Hypoxia-preconditioned adipose-derived stem cell exosomes promote osteogenic differentiation and bone formation in bone marrow mesenchymal stem cells through the Piezo1/Ca2+ signaling axis

Figure 1 Hypoxia promotes exosomal release from adipose-derived stem cells and uptake by bone marrow mesenchymal stem cells. A: Representative transmission electron microscopy images showing exosome morphology (scale bar: 200 nm); B: Nanoparticle tracking analysis showing size distribution of adipose-derived stem cells-derived exosomes; C: Western blot analysis and quantification of exosomal markers CD81 and tumor susceptibility gene 101, with calnexin as a negative control (n = 3, one-way ANOVA); D: Fluorescence microscopy images showing colocalization of exosomes with bone marrow mesenchymal stem cells. Nuclei are stained with DAPI (blue), PKH67-labeled exosomes are shown in green, and merged images are presented (scale bar: 100 μm). ^aP < 0.05; ^bP < 0.01; ^cP < 0.001. Exos: Exosomes; HY-Exos: Hypoxia-preconditioned exosomes; ADSCs: Adipose-derived stem cells; TSG101: Tumor susceptibility gene 101.