Figure 3. Estradiol augments TCF/LEF-dependent transcription in N2a-m cells.

N2a-m cells were transfected with the TOPFlash or FOPFlash reporter plasmid with EGFP-pCDNA3, and the cells were then treated with estradiol and other test compounds for the different times and at the different concentrations indicated. (A–B), Soluble extracts from estradiol treated cells were obtained and luciferase activity was measure as indicated in the Methods. The normalized data were expressed in relative light units (RLU) compared to the control solvent, and the response was maximal at 60 min using 100 nM. (C).The effect of estradiol can be prevented by prior exposure to the ER antagonist ICI 182780 10 µM for 2 hr. (D), Specific agonists of each estrogen receptor (PPT: ERα agonist, and DPN: ERβ agonist, at two concentrations, 5 and 10 nM) also induced TCF/LEF-mediated transcription although PPT was more efficient than DPN. The graphs show the normalized luciferase activity from at least three independent experiments. The P value from the Student's t-test was * (P≤0.05), ** (P≤0.01). The single * or ** compares data to control whereas the bar between different points shows statistical differences between them.