Il-1 Beta Upregulates Star And Progesterone Production Through The Erk1/2-And P38-Mediated Creb Signaling Pathways In Human Granulosa-Lutein Cells

The proinflammatory cytokine interleukin-1 beta (IL-1 beta) may be involved in several ovulation-associated events, such as protease synthesis, prostaglandin production, and steroidogenesis in granulosa cells. However, the exact effect of IL-1 beta on progesterone synthesis in granulosa cells and the underlying mechanism remain unclear. By using cultured granulosa-lutein cells collected from women undergoing in vitro fertilization or intracytoplasmic sperm injection, we found that IL-1 beta upregulated steroidogenic acute regulatory protein (StAR) expression and progesterone synthesis in granulosa-lutein cells, which was comparable with luteinizing hormone effect and could be abolished by an IL-1 receptor antagonist. Moreover, IL-1 beta activated the phosphorylation of cyclic adenosine monophosphate response element-binding protein (CREB), and knockdown of CREB attenuated the induction of StAR expression and progesterone synthesis by IL-1 beta in granulosa-lutein cells. Furthermore, IL-1 beta activated the extracellular signal-regulated kinase (ERK)1/2 and p38 pathways and inhibition of the ERK1/2 and p38 pathways attenuated the IL-1 beta-induced phosphorylation of CREB, StAR expression, and progesterone synthesis in granulosa-lutein cells. In conclusion, IL-1 beta could upregulate StAR expression and stimulate progesterone biosynthesis through increase in CREB phosphorylation via activating the ERK1/2 and p38 pathways in human granulosa-lutein cells.