Fig. 2. hCG and Activin-A have opposing effects on the luteinization phenotype in human luteal granulosa cells.

hCG treatment (10IU/ml) significantly upregulated StAR, 3β-HSD expression along with phospho-c-Jun (a, b) in western blotting and increased P₄ output in the cells (c). By contrast, activin-A (25 ng/ml) exerted opposite effects and reduced P₄ production. FSH (25 mIU/ml) increased the expression of aromatase (a, b) and increased E₂ production (c) but did not change the levels of total or phosphorylated c-Jun.