Figure 4

Leptin acted through ERK1/2 and p-38 pathways to modulate steroidogenesis in human granulosa cells. Cells were treated with leptin (1000 ng/ml) in the presence or absence of ERK1/2 inhibitor (PD98059, 25 μM), p38 inhibitor (SB203580, 10 μM) and JNK inhibitor (SP600125, 25 μM) for 24 h. Cell lysates were collected and subjected to Western blot analysis to monitor the expression of StAR protein (A) and media were collected and assayed for progesterone production by ELISA (B). Upper bands in (A) are Western blotting representative data from three independent experiments. Lower bars were integrated optical density (IOD) of StAR protein expression with β-actin normalization. Each data point in (A) represents the mean ± SD of three independent experiments. Each data point in (B) represents the mean ± SEM of three independent experiments. * above the bars indicate that those groups differ significantly from untreated control (P < 0.05).