EGF-like Growth Factors Induce COX-2-Derived PGE2 Production Through ERK1/2 in Human Granulosa Cells

Context: Aberrant regulation of ovulation is one of the major causes of infertility. In animal models, 3 epidermal growth factor (EGF)-like growth factors, amphiregulin (AREG), betacellulin (BTC), and epiregulin (EREG), have been shown to be involved in ovulation by regulating cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production. However, whether the same is true in humans remains largely unknown. Objective: Our objective was to investigate the effects of AREG, BTC, and EREG on COX-2 expression and PGE2 production in human granulosa cells. Design and Setting: SVOG cells are human granulosa cells that were obtained from women undergoing in vitro fertilization and immortalized with SV40 large T antigen. SVOG cells were used to investigate the effect of AREG, BTC, and EREG on ovulation-related functions at an academic research center. Main Outcome Measures: Levels of mRNA and protein were examined by quantitative RT-PCR and Western blotting, respectively. The protein levels of PGE2 were measured by ELISA. Results: LH treatment upregulated AREG, BTC, EREG, and COX-2. Knockdown of EGF receptor (EGFR) attenuated LH-induced COX-2 expression and PGE2 production. Treatment with AREG, BTC, and EREG upregulated COX-2 expression and PGE2 production. The stimulatory effects of AREG, BTC, and EREG on COX-2 expression and PGE2 production were blocked by inhibition of EGFR activity and expression. AREG-, BTC-, and EREG-activated ERK1/2 signaling, but not Akt signaling, was required for AREG-, BTC-, and EREG-induced COX-2 expression and PGE2 production. Conclusion: AREG, BTC, and EREG induced PGE2 production by upregulating COX-2 expression through ERK1/2 signaling in human granulosa cells.