FIGURE 5.

4-HNE or H₂O₂ increase PPARγ2 expression in C2C12 cells. PPARγ2 gene expression by quantitative PCR in C2C12 cells pretreated with vehicle (PBS), 4-HNE (20 μm), or H₂O₂ (100 μm) for 1 h followed by vehicle or Wnt3a (50 ng/ml) for 5 h (A) or in cells pretreated with vehicle or H₂O₂ as above followed by vehicle or indicated concentration of LiCl for 5 h (B). C, luciferase activity in C2C12 cells transfected with a PPARE-luc reporter construct and co-transfected with either an empty vector (pcDNA) or a constitutively active β-catenin mutant. Cells were then treated with vehicle, 4-HNE, or H₂O₂ as in A for 24 h. Bars represent the mean ± S.D. of triplicate determinations. Numbers in parentheses represent -fold change versus respective vehicle control. *, p < 0.05 versus respective vehicle control (A and B) or empty vector control (C). †, p < 0.05 versus cells given neither 4-HNE nor Wnt3a.