Fig. 5

Gene expression analysis for fold-change of chondrogenic markers in physioxia relative to hyperoxia demonstrates that high-GAG groups of both MSCs and ACPs are highly responsive to oxygen level and upregulate a majority of genes representative of the articular cartilage phenotype in low-oxygen environments. Data are mean ± standard deviation of fold-change in gene expression for each group (n = 8). Statistical significance defined as *p < 0.05 by a paired t test for normal data and a Wilcoxon matched-pairs signed rank test for nonnormal data. ACP articular cartilage progenitor, MSC mesenchymal stem cell