Limits...
Connexin expression and gap junctional coupling in human cumulus cells: contribution to embryo quality.

Wang HX, Tong D, El-Gehani F, Tekpetey FR, Kidder GM - J. Cell. Mol. Med. (2008)

Bottom Line: 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 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.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada.

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.

Show MeSH

Related in: MedlinePlus

Co-expression of Cx26, Cx32 and Cx43 in human cumulus cells. Cells were doubly labelled with primary antibodies against different connexins and the bound primary antibodies detected using different fluorescently tagged secondary antibodies. Hoechst dye was used for nucleus staining. The magnifications are shown by the scale bars.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3823412&req=5

fig03: Co-expression of Cx26, Cx32 and Cx43 in human cumulus cells. Cells were doubly labelled with primary antibodies against different connexins and the bound primary antibodies detected using different fluorescently tagged secondary antibodies. Hoechst dye was used for nucleus staining. The magnifications are shown by the scale bars.

Mentions: To explore the possibility of connexin co-localization, we used double-labelled immunofluorescence. The results of these experiments were consistent with those shown in Fig. 2, in that Cx26 and Cx32 were restricted to the cytoplasm while Cx43 formed numerous plaques between the cells (Fig. 3). At least two of Cx26, Cx32 and Cx43 could be found in the same cells, but Cx26 and Cx32 did not co-localize with Cx43. Interestingly, Cx26 and Cx32 co-localized in the cytoplasm (Fig. 3).


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

Wang HX, Tong D, El-Gehani F, Tekpetey FR, Kidder GM - J. Cell. Mol. Med. (2008)

Co-expression of Cx26, Cx32 and Cx43 in human cumulus cells. Cells were doubly labelled with primary antibodies against different connexins and the bound primary antibodies detected using different fluorescently tagged secondary antibodies. Hoechst dye was used for nucleus staining. The magnifications are shown by the scale bars.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3823412&req=5

fig03: Co-expression of Cx26, Cx32 and Cx43 in human cumulus cells. Cells were doubly labelled with primary antibodies against different connexins and the bound primary antibodies detected using different fluorescently tagged secondary antibodies. Hoechst dye was used for nucleus staining. The magnifications are shown by the scale bars.
Mentions: To explore the possibility of connexin co-localization, we used double-labelled immunofluorescence. The results of these experiments were consistent with those shown in Fig. 2, in that Cx26 and Cx32 were restricted to the cytoplasm while Cx43 formed numerous plaques between the cells (Fig. 3). At least two of Cx26, Cx32 and Cx43 could be found in the same cells, but Cx26 and Cx32 did not co-localize with Cx43. Interestingly, Cx26 and Cx32 co-localized in the cytoplasm (Fig. 3).

Bottom Line: 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 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.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada.

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.

Show MeSH
Related in: MedlinePlus