Figure 1.

Adipose tissue-derived mesenchymal stromal cells (ASCs) under physioxia (5% O₂) and short-term hypoxic stress (0.1% O₂, 24 h). (a) Phase-contrast microscopy of ASCs showed no morphological differences (scale bar, 100 μm). (b) The phenotype of ASCs was identified by flow cytometric analysis. ASCs were positive for CD73, CD90, and CD105 and negative for CD45. The black line indicates the isotype control, the green line indicates tissue O₂-adapted ASCs, and the red line indicates ASCs after short-term hypoxic stress. (c) Cell growth was evaluated by growth curves and population doubling time over 4 days. The data are presented as the mean ± standard deviation (n = 3). (d) Osteogenic and (e) adipogenic induction was assessed by alizarin red S staining of the mineralized matrix and Oil Red O staining of intracellular neutral lipid droplets, respectively (scale bar, 100 μm).