Upregulation of AREG, EGFR, and HER2 contributes to increased VEGF expression in granulosa cells of patients with OHSS

Abstract

Ovarian hyperstimulation syndrome (OHSS) is a serious iatrogenic complication in women undergoing induction of ovulation with human chorionic gonadotropin (hCG) for assisted reproductive techniques. Amphiregulin (AREG) is the most abundant epidermal growth factor receptor (EGFR) ligand expressed in human granulosa cells and follicular fluid and can be upregulated by luteinizing hormone (LH)/hCG. However, whether the expression levels of AREG, EGFR, and HER2 change in the granulosa cells of OHSS patients remains unknown. If it does, whether these molecules are involved in the development of OHSS requires investigation. In the present study, we showed that AREG, EGFR, and HER2 transcripts in granulosa cells as well as follicular fluid AREG proteins were elevated in OHSS patients. Increased AREG levels were associated with transcript levels and follicular content of vascular endothelial growth factor (VEGF), the marker for OHSS pathology. Treatment of cultured granulosa cells with AREG stimulated VEGF expression and secretion, with granulosa cells from OHSS patients showing more rapid and pronounced increases than the non-OHSS group. In addition, siRNA-mediated knockdown of EGFR and AREG attenuated the hCG-induced upregulation of VEGF. This study demonstrated that granulosa cell-secreted AREG plays an important role in the development of OHSS, suggesting that the EGFR/HER2-mediated signaling could be a novel drug target for the prevention and treatment of OHSS.