9‐cis‐retinoic acid during in vitro maturation improves development of the bovine oocyte and increases midkine but not IGF‐I expression in cumulus‐granulosa cells

Abstract

The isomer 9-cis of retinoic acid (9-cis-RA) exerts a beneficial effect on bovine in vitro development when added to in vitro maturation (IVM) culture. In the present work, 9-cis-RA 5 nM was found to be stimulatory as opposed to 500 nM (toxic). Cumulus-oocyte complexes (COCs) were treated with the found physiological dose 9-cis-RA 5 nM, and the next determinations performed: (1) relative expression of midkine (MK) and IGF-I, by reverse transcriptasepolymerase chain reaction (RT-PCR), in cumulusgranulosa cells detached from oocytes; (2) cytoplasmic granular migration, by labeling of oocytes with fluoroscein isothiocyanate lectins; and (3) in vitro survival of blastocysts after vitrification and warming. Gene expression of MK was enhanced by 9-cis-RA, but not by 1% ethanol (vehicle). However, we did not detect IGF-I expression, both in dependence on or in the absence of 9-cis-RA acting on cumulus-granulosa cells. The ability of vitrified blastocysts to survive in vitro was not improved by 9-cis-RA. Nevertheless, since only blastocysts obtained from oocytes matured with serum survived, more factors should be considered when evaluating cryopreservation survival. The complete granular migration observed in oocytes matured with 9-cis-RA anticipates the gain in developmental competence of the oocyte, being MK probably involved in this beneficial effect. Mol. Reprod.

Retinoid‐dependent mRNA expression and poly‐(A) contents in bovine oocytes meiotically arrested and/or matured in vitro

“…In agreement with these findings, the addition of 9-cis-RA to in vitro maturation (IVM) cultures stimulated cortical granule migration in bovine oocytes both matured and meiotically arrested for a 24-hr culture period (Duque et al, 2002). Increased embryonic development (Duque et al, 2002;Gómez et al, 2003;Hidalgo et al, 2003), embryonic quality (Duque et al, 2002;Hidalgo et al, 2003), cryopreservation tolerance (Duque et al, 2002;Gómez et al, 2003), and pregnancy rates , were also obtained after oocyte maturation with 9-cis-RA. Recently, we showed increased midkine expression in bovine cumulus-granulosa cells in response to RA .…”

“…The gene sequences activated or repressed by RA at meiotic arrest, leading to increased polyadenylation, could therefore explain part of the effects on development observed in former oocyte studies (Duque et al, 2002;Gómez et al, 2003;Hidalgo et al, 2003). These changes included increased expression in granulosa cells of midkine , a retinoid responsive gene, whose recombinant peptide product stimulates embryonic development in vitro up to the blastocyst stage (Ikeda et al, 2000a,b).…”

“…The developmental competence of the bovine oocyte is stimulated by 9-cis-RA (Duque et al, 2002;Gómez et al, 2003;Hidalgo et al, 2003), while micromolar concentrations suppress embryo development . In addition, after comparing our gene expression profile found for Cyclin B1, MnSOD, and G6PDH with a previous study using a serum-supplemented maturation medium (Lonergan et al, 2003a), it is again demonstrated that serum yields artifacts.…”

Effects of retinoic acid on maturation of immature mouse oocytes in the presence and absence of a granulosa cell co-culture system

“…In this manner, Mohan et al have shown that cumulus granulosa cells contain endogenously activated retinoid receptors that can reply to RA [19]. The beneficial effects of RA on in vitro maturation of cumulus oocyte complexes has been previously described [5,6,12,20,21] however no reports have discussed the effects of RA on the developmental competence of naked immature oocytes. In a previous study, we have shown that the use of a physiological dose of all-trans retinoic acid (t-RA; 2 μM) during in vitro maturation and under precise conditions could improve both maturation and developmental competence of denuded immature mouse oocytes [22].…”

“…In a previous study, we have shown that the use of a physiological dose of all-trans retinoic acid (t-RA; 2 μM) during in vitro maturation and under precise conditions could improve both maturation and developmental competence of denuded immature mouse oocytes [22]. Therefore, based on this and other studies [5,6,12,[19][20][21][22] we assume that the cumulus granulosa cells might be a target for added RA during in vitro maturation, which could improve embryo development. In this study, we evaluate the effects of t-RA in association with a co-culture granulosa cell monolayer on the IVM of naked immature mice oocytes and then follow them until the blastocyst stage.…”