Connexin expression and gap junctional coupling in human cumulus cells: Contribution to embryo quality

H. X. Wang, D. Tong, F. El-Gehani, F. R. Tekpetey, G. M. Kidder

Research output: Contribution to journalArticlepeer-review

55 Scopus citations

Abstract

Gap junctional coupling among cumulus cells is important for oogenesis since its deficiency in mice leads to impaired folliculogenesis. Multiple connexins (Cx), the subunits of gap junction channels, have been found within ovarian follicles in several species but little is known about the connexins in human follicles. The aim of this study was to determine which connexins contribute to gap junctions in human cumulus cells and to explore the possible relationship between connexin expression and pregnancy outcome from in vitro fertilization (IVF). Cumulus cells were obtained from IVF patients undergoing intra-cytoplasmic sperm injection (ICSI). Connexin expression was examined by RT-PCR and confocal microscopy. Cx43 was quantified by immunoblotting and gap junctional coupling was measured by patch-clamp electrophysiology. All but 5 of 20 connexin mRNAs were detected. Of the connexin proteins detected, Cx43 forms numerous gap junction-like plaques but Cx26, Cx30, Cx30.3, Cx32 and Cx40 appeared to be restricted to the cytoplasm. The strength of gap junctional conductance varied between patients and was significantly and positively correlated with Cx43 level, but neither was correlated with patient age. Interestingly, Cx43 level and intercellular conductance were positively correlated with embryo quality as judged by cleavage rate and morphology, and were significantly higher in patients who became pregnant than in those who did not. Thus, despite the presence of multiple connexins, Cx43 is a major contributor to gap junctions in human cumulus cells and its expression level may influence pregnancy outcome after ICSI.

Original languageEnglish (US)
Pages (from-to)972-984
Number of pages13
JournalJournal of Cellular and Molecular Medicine
Volume13
Issue number5
DOIs
StatePublished - May 2009
Externally publishedYes

Keywords

  • Conductance
  • Connexin43
  • Gap junction
  • Pregnancy

ASJC Scopus subject areas

  • Molecular Medicine
  • Cell Biology

Fingerprint

Dive into the research topics of 'Connexin expression and gap junctional coupling in human cumulus cells: Contribution to embryo quality'. Together they form a unique fingerprint.

Cite this