Figure 2.

ZEB1 modestly represses human LHB transcription. (A) LβT2 cells were transfected with 225 ng/well of WT −232/+5 murine Lhb-luc or WT −196/+9 human LHB-luc reporter, as well as 25 ng/well ZEB1 expression vector. Cells were treated with GnRH as in Fig. 1. (B) LβT2 cells were transfected with 225 ng/well WT −232/+5 mLhb-luc or WT −196/+9 hLHB-luc reporter, and 25 ng/well ZEB1 and/or 50 ng/well EGR1 expression vector. (C) Schematic of the WT murine Lhb (blue) and WT human LHB (pink) promoters. Putative ZEB1 cis-elements are boxed. Chimeric murine Lhb and human LHB promoters are depicted. Dashed lines at the top indicate the sequence comprising swapped regions in the chimeric reporters. (D-I) LβT2 cells were transfected with 225 ng/well of the indicated reporters, 25 ng/well ZEB1 expression vector, and treated with GnRH. In A-B and D-I, luciferase assays were performed as in Fig. 1. Data represent the mean of 3 or more independent experiments performed in triplicate. Percent repression of GnRH-induced promoter-reporter activity by ZEB1 is shown in red. White circles represent experimental replicates. Data were analyzed by two-way ANOVA followed by Holm–Sidak multiple comparisons test. Bars with different letters differ significantly.

Abbreviations: m2h, mouse-to-human; h2m, human-to-mouse.