Figure 8.

Involvement of AP-1 in the enhancing effects of Nrf2 activators on 1,25D₃-induced cell differentiation, VDR and RXRα protein expression, and VDRE transactivation. HL60 cells were preincubated for 24 h either without oligodeoxynucleotide (ODN) or with 10 μM TRE-ODN or mTRE-ODN followed by treatment with 1,25D₃, CA, MMF, or their combinations at the indicated concentrations for an additional 48 h. (a) Averaged CD14 and CD11b surface expression, as measured via flow cytometry. (b,c) Representative Western blots showing changes in VDR and RXRα protein levels. Calreticulin was used as a protein loading control. (d) Cells were transiently transfected with VDREx6-Luc and Renilla luciferase plasmids, followed by pretreatment with or without TRE-ODN or mTRE-ODN for 24 h. Cells were then incubated with or without the indicated test agents for another 24 h, followed by measuring luciferase activity. The data are means ± SD of 3 experiments. *, p < 0.05; **, p < 0.01; ***, p < 0.001; ****, p < 0.0001 vs. corresponding control group; #, p < 0.05; ##, p < 0.01; ###, p < 0.001; combination vs. corresponding sum of the effects of single agents; $$, p < 0.01, TRE-ODN-treated group vs. corresponding TRE-ODN untreated group.