Fig. 4: β-catenin initiates Oct4 activation.

a–c β-catenin overexpression increases the mRNA and protein levels of β-catenin and Oct4. Their mRNA expression levels were measured by qRT‒PCR (a). The protein levels of β-catenin and Oct4 were then detected using western blotting (b, c). d–f The mRNA and protein levels of β-catenin and Oct4 were measured by qRT‒PCR (d) and immunoblotting (e and f) in PBMSCs treated with vehicle, oeOct4, shOct4, or oeOct4 plus shOct4. g Chromatin immunoprecipitation (ChIP) assay for the binding of β-catenin to the Oct4 promoter. Anti-IgG was used as a negative control, and anti-RNA-polymerase II was used as a positive control. h Representative immunostaining in the PBMSCs treated with vehicle, oeOct4, shOct4, oeOct4, or shOct4 showing that β-catenin overexpression increases the expression of both β-catenin and Oct4, but alteration of Oct4 expression did not significantly change β-catenin expression. β-Catenin or Oct4 silencing markedly suppressed the expression of Oct4. β-Catenin and Oct4 were stained red and green, respectively. The nuclei of PBMSCs were counterstained blue using 4,6-diamino-2-phenyl indole (DAPI). Scale bars = 20 µm. β-Catenin was mainly expressed in the cytoplasm and partially in the cell nucleus. Oct4 was mainly localized in the nucleus. All graphical data are shown as the means ± SEMs. P < 0.05: * vs. the vehicle group, # vs. the oeβ-catenin group, Δ vs. the shβ-catenin group, n = 10 for each group.