Fig. 9.

STAT3 signaling alters the negative action of T₃ on prepro-TRH gene expression. 293T cells were cotransfected with TRβ2, ObRb, STAT3, β-galactosidase expression vector, and the human prepro-TRH promoter linked to the luciferase reporter. Cells were treated overnight with T₃ (10–100 nM) and further treated with leptin (1–100 nM) for 6 h. For each condition, the luciferase activity was normalized to β-galactosidase activity. Results are shown as the relative luciferase activity normalized to each basal activity of the promoter for the different leptin treatments (0, 1, 10, and 100 nM). Results are the mean of 3 separate experiments performed in triplicate. ^aP < 0.05 vs. 100% luciferase activity (T₃ = 0 nM) at the same concentration of leptin; ^bP < 0.05 vs. normalized luciferase activity at leptin = 0 nM and the same concentration of T₃.