Mohamad Salhab and Sophie Dhorne-Pollet contributed equally to this work.
In vitro maturation of oocytes alters gene expression and signaling pathways in bovine cumulus cells†
Article first published online: 30 JAN 2013
Copyright © 2012 Wiley Periodicals, Inc.
Molecular Reproduction and Development
Volume 80, Issue 2, pages 166–182, February 2013
How to Cite
Salhab, M., Dhorne-Pollet, S., Auclair, S., Guyader-Joly, C., Brisard, D., Dalbies-Tran, R., Dupont, J., Ponsart, C., Mermillod, P. and Uzbekova, S. (2013), In vitro maturation of oocytes alters gene expression and signaling pathways in bovine cumulus cells. Mol. Reprod. Dev., 80: 166–182. doi: 10.1002/mrd.22148
- Issue published online: 13 FEB 2013
- Article first published online: 30 JAN 2013
- Accepted manuscript online: 27 DEC 2012 04:26PM EST
- Manuscript Accepted: 17 DEC 2012
- Manuscript Received: 19 OCT 2012
- French National Research Agency and Apisgen (OSCILE ANR-08-GENM-033 and OVOGENAE2 ANR-07-GANI-004 programs)
- oocyte quality;
- cumulus transcriptome;
- signaling pathways;
In vitro maturation (IVM) of immature oocytes is widely used in assisted reproduction technologies in cattle, and is increasingly used to treat human infertility. The development competence of IVM oocytes, however, is lower than preovulatory, in vivo-matured oocytes. During maturation, cumulus cells (CC) are metabolically coupled with an oocyte and support the acquisition of its developmental potential. Our objective was to identify genes and pathways that were affected by IVM in bovine CC. Microarray transcriptomic analysis of CC enclosing in vitro- or in vivo-mature oocytes revealed 472 differentially expressed genes, including 28% related to apoptosis, correlating with twofold higher cell death after IVM than in vivo, as detected by TUNEL. Genes overexpressed after IVM were significantly enriched in functions involved in cell movement, focal adhesion, extracellular matrix function, and TGF-beta signaling, whereas under-expressed genes were enriched in regulating gene expression, energy metabolism, stress response, and MAP kinases pathway functions. Differential expression of 15 genes, including PAG11 (increased) and TXNIP (decreased), which were never detected in CC before, was validated by real-time RT-PCR. Moreover, protein quantification confirmed the lower abundance of glutathione S-transferase A1 and prostaglandin G/H synthase 2, and the higher abundance of hyaluronan synthase 2 and SMAD4, a member of TGF-beta pathway, in CC after IVM. Phosphorylation levels of SMAD2, MAPK3/1, and MAPK14, but not MAPK8, were higher after IVM that in vivo. In conclusion, IVM provokes the hyper-activation of TGF-beta and MAPK signaling components, modifies gene expression, leads to increased apoptosis in CC, and thus affects oocyte quality. Mol. Reprod. Dev. © 2012 Wiley Periodicals, Inc.