FIGURE 7.

Peroxidized PUFAs prevent Wnt3a-induced transcription, proliferation, and osteoblastogenesis. A, luciferase activity in C2C12 cells transfected with a TCF-luc reporter construct. Cells were pretreated with vehicle (3.3% BSA in PBS) or the indicated peroxidized PUFAs (100 μm) for 1 h, then with Wnt3a (10 ng/ml) for 24 h. B, proliferation of C2C12 cells, determined by bromodeoxyuridine (BrdU) incorporation. Cells were pretreated with vehicle, RGL (5 nm), or the indicated peroxidized PUFAs (10 μm) for 1 h followed by Wnt3a (25 ng/ml) for 3 days. C, mineralized matrix visualized and quantified by alizarin red staining. Cultures of femoral bone marrow cells were established as described under “Experimental Procedures,” then incubated with RGL (1 nm) or the indicated peroxidized PUFAs (100 μm) without or with Wnt3a (25 ng/ml) for 18 days. Mineralized matrix was visualized by staining with alizarin red (left panel) and quantified after extraction (right panel). 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. †, p < 0.05 versus cells given neither PPARγ ligands nor Wnt3a.