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 2 Hypoxia-preconditioned exosomes regulate osteogenic differentiation of bone marrow mesenchymal stem cells. A and B: Alkaline phosphatase and alizarin red S staining with corresponding quantitative analyses after osteogenic induction (scale bar: 100 μm); C and D: Western blot analysis and quantification of runt-related transcription factor 2 and osterix expression in bone marrow mesenchymal stem cells treated with normoxic and hypoxia-conditioned exosomes (n = 3, one-way ANOVA). ^aP < 0.05; ^bP < 0.01; ^cP < 0.001. ALP: Alkaline phosphatase; ARS: Alizarin red S; PBS: Phosphate-buffered saline; Exos: Exosomes; HY-Exos: Hypoxia-preconditioned exosomes; Runx2: Runt-related transcription factor 2.