In order to investigate the roles of epidermal growth factor (EGF) and transforming growth factor (TGF)-α in ovulation, we studied the production of interleukin (IL)-8 and growth-regulated oncogene (GRO)-α in cultured human granulosa-lutein cells.
Granulosa-lutein cells obtained from the follicular fluids of in vitro fertilization and embryo transfer patients were cultured and treated with EGF, TGF-α, tumor necrosis factor (TNF)-α or 12-O-tetradecanoylphorbol 13-acetate (TPA). An immortalized granulosa cell line (GC1a) was also cultured and treated with EGF, TGF-α or mitogen-activated protein kinase kinase inhibitor. The supernatants were collected, and IL-8 and GRO-α were measured by ELISA.
The levels of IL-8 and GRO-α were significantly increased after treatment with EGF, TGF-α, TNF-α and TPA by primary cultured granulosa-lutein cells. The levels of IL-8 and GRO-α were also significantly increased after treatment with EGF or TGF-α in a dose-dependent manner by GC1a. When GC1a was treated with EGF, TGF-α or U0126, the levels of IL-8 and GRO-α were significantly decreased.
Our data indicate that the production of IL-8 and GRO-α is upregulated by EGF and TGF-α. It is suggested that EGF and TGF-α may play an important role in luteinization processes involving IL-8 and GRO-α production.