Fig. 4

Effects of the inhibitor of ERK-1/2 on H3K4me3 of the StAR promoter region and StAR mRNA expression in granulosa cells undergoing luteinization. Granulosa cells were isolated 48 h after eCG injection, and incubated with or without hCG for 4 h to induce luteinization (a, b). Granulosa cells were also incubated with or without the inhibitor of ERK (U0126, 10 M) for 2 h prior to hCG stimulation (c, d). StAR mRNA expression was measured by real-time RT-PCR. The value was normalized to an internal control (GADPH). Data were expressed as a percentage of the group without hCG. H3K4me3 of the StAR promoter region was analyzed by a ChIP assay. The IP/INPUT ratio was calculated and data were expressed as a percentage of the group without U0126. Each bar represents the mean +/− SEM of three independent experiments. *; p < 0.05 vs. hCG (−) or U0126 (−)