Figure 4

TSN activates the Wnt/β-catenin pathway in 3T3-L1 adipocytes. (A) Effects of TSN treatment on the mRNA expression of LRP6, DVL2, β-catenin, and CCND1 analyzed by RT-PCR; the differentiated group without TSN treatment served as the control group. Additionally, the corresponding semi-quantitative analysis was based on optical density determined with image J software. β-actin was used as an internal control. Values are expressed as mean ± SD (fold of control) of three independent experiments. UND: undifferentiated samples; *P < 0.05, **P < 0.01 and ^#P < 0.001 vs. control (0 nM TSN). (B) Effects of TSN treatment on the protein expression of β-catenin and p-GSK3β analysed by western blot. β-actin was used as an internal control. The results are expressed as mean ± SD (fold of NC or control) of three independent experiments. UND: undifferentiated samples; *P < 0.05, **P < 0.01 and ^#P < 0.001 vs. control. (C) Effects of β-catenin siRNA on the mRNA expression of β-catenin, CCND1, PPAR-γ, and C/EBP-α in the presence and absence of TSN determined by RT-PCR, β-actin was used as an internal control. Values are expressed as mean ± SD (fold of NC or control) of three independent experiments. *P < 0.05, **P < 0.01 and ^#P < 0.001 vs. control; ^ФP < 0.001 vs. NC + TSN. (D) Increase of lipid content after β-catenin siRNA transfection was evidenced by Oil Red O staining and determined at OD_{540 nm} with a M200 PRO multi-functional microplate reader. Scale bars: 20 μM. Values are expressed as mean ± SD (fold of NC or control) of three independent experiments. **P < 0.01 vs NC and ^#P < 0.001 vs. NC + TSN.