Epiregulin-dependent amphiregulin expression and ERBB2 signaling are involved in luteinizing hormone-induced paracrine signaling pathways in mouse ovary

Kyoungmi Kim, Hyunji Lee, David W. Threadgill, Daekee Lee

Research output: Contribution to journalArticle

17 Citations (Scopus)


Sustained EGF receptor (EGFR) phosphorylation by de novo synthesis of EGFR ligands plays an essential role in mediating luteinizing hormone (LH)-induced ovulation process in the preovulatory follicles (POFs). In the present study, the effect of epiregulin (EREG) on oocyte maturation and ovulation was investigated using Ereg knockout (Ereg -/- ) mice congenic on a C57BL/6 background. Rate of spontaneous oocyte meiotic resumption of denuded oocytes (DOs) or cumulus cell-oocyte complexes (COCs) in vitro is similar between wild-type and Ereg -/- mice. However, gonadotropin-induced meiotic resumption in vivo is attenuated, and the number of COCs with expanded cumulus matrix and superovulated eggs dramatically decrease in Ereg -/- mice. Nonetheless, the number of eggs ovulated during normal estrus cycles and litter sizes in Ereg -/- mice are comparable to those of wild-type littermates. In contrast to other EGFR ligands, induction of amphiregulin (Areg) mRNA is severely reduced in ovaries collected from Ereg -/- mice either after human chorionic gonadotropin (hCG) treatment in immature mice or LH surge in adults. Gonadotropin-induced EGFR and ERBB2 phosphorylation in ovaries is attenuated in immature Ereg -/- mice, and MAPK3/1 phosphorylation and prostaglandin synthase 2 (PTGS2) protein levels are reduced. This attenuation, however, is no longer detectable in adult Ereg -/- mice after LH surge. This study implicates that EREG mediates signals downstream of Areg mRNA expression and that EGFR-ERBB2 signals contributes to regulation of ovulation process.

Original languageEnglish
Pages (from-to)319-324
Number of pages6
JournalBiochemical and biophysical research communications
Issue number2
Publication statusPublished - 2011 Feb 11
Externally publishedYes



  • Amphiregulin
  • EGFR and ERBB2 phosphorylation
  • Epiregulin
  • Oocyte maturation
  • Ovulation

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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