Figure 2

Activation of silent genes.

ADSCs were encapsulated in the Soft, Med, or Stiff Col-Tgel and grown with or without 5-Aza-CR. (A) Expression of Oct4, Abcg2 and Hif1a was evaluated by RT-PCR. The presence of 5-Aza-CR enhanced the expression of Oct4, Abcg2 and Hif1a. The stem cell markers Oct4 and Abcg2, as well as the hypoxic marker Hif1a were highly expressed in stiffer matrices (i.e., Med and Stiff Col-Tgels), whereas much lower expression was observed in the Soft Col-Tgel. Values in the treated group were normalized by corresponding values in the non-treated group and scaled between 100% (upregulation) and −100% (downregulation). Data are presented as the mean ± standard deviation of 4 samples and statistical differences (Tukey-Kramer HSD test) are indicated as follows: *P < 0.05, **P < 0.01 and ***P < 0.001. (B) OCT4 immunostaining. Untreated cells were readily activated around the periphery but not within the center of the gel. In contrast, cells grown in the presence of 5-Aza-CR were activated evenly throughout the gel. Black arrows indicate positive staining (Scale bars, 1000 μm).