Research Paper Volume 12, Issue 2 pp 1591—1609

Chikusetsu saponin IVa protects pancreatic β cell against intermittent high glucose-induced injury by activating Wnt/β-catenin/TCF7L2 pathway

Figure 6. Involvement of Wnt/TCF7L2 signaling in the protective effect of CHS on islets β cell. βTC3 cells were treated with CHS and IHG or SHG, then the RNA was extracted by TRIZOL. The mRNA expression levels of Wnt2 (A), Wnt3a (B), Wnt4 (C), Wnt5a (D), and Wnt10b (E) were measured by RT-PCR. (F) The protein expression levels of Wnt3a was measured by western blotting after different treatments. The effects of CHS on β-catenin expression levels in the cytoplasm (G) and nuclear (H) were measured by western blotting. (I) The effects of CHS on protein expression levels of Axin-2, c-Myc, Naked-1 and P-GSK-3β. βTC3 cells were treated with CHS and XAV-939 (a Wnt/β-catenin antagonist, 10μM), and then subjected to IHG. (J) The protein expression levels of TCF7L2, cyclin D1, skp2, p53, p21 and GIPR were measured by western blotting. (K) Cell variability was measured by CCK8 assay. (L) Insulin secretion levels was measured by an insulin RIA kit. (M) BrdU positive ratio was calculated from the BrdU positive cell numbers vs total cell numbers. Data are representative of three independent experiments. ##P<0.01 vs. NG treatment group, **P<0.01 vs. IHG treatment group, ΔΔP<0.01 vs. scrb treatment group, &&P<0.01 vs.CHS treatment group.