Figure 1.

Expression of genes associated with chondrogenic differentiation under normoxic or hypoxic conditions. C3H10T1/2 cells were cultured as cell pellets under normoxic (21% O₂) or hypoxic (2% O₂) conditions for 3-21 days to induce chondrogenesis. The expression of chondrogenesis related marker genes was assessed by PCR and normalized to the expression of ribosomal 18sRNA. The fold change in gene expression was calculated using the 2^-ΔΔCt method comparing with undifferentiated cells in normoxic conditions. The time points when gene expression was assessed are indicated on the X-axis. The mRNA expression levels of (A) microRNA-124 (miR-124); (B) NFATc1; (D) Sox9; (E) aggrecan; (F) collagen IIa1; and (G) collagen Xa1 are shown. The bars represent means ± SD (n=3; *P<0.05; **P<0.01; N.S.: not significant). (C) NFATc1 expression at the protein level was assessed by Western blot. (H) Serial paraffin sections of pellet after 3 and 21 days were stained with toluidine blue; representative images are shown. Scale bar =100 μm.