The 9-Cis Retinoic Acid Signaling Pathway and Its Regulation of Prostaglandin-Endoperoxide Synthase 2 During In Vitro Maturation of Pig Cumulus Cell-Oocyte Complexes and Effects on Parthenogenetic Embryo Production1

Abstract

The addition of 9-cis retinoic acid to the oocyte maturation culture medium has a beneficial effect on in vitro fertilized embryos. However, the mechanism of this activity is not known. Therefore, this study was done to elucidate the effect of 9-cis retinoic acid on parthenogenetic embryo production and its signaling pathway and molecular function during in vitro maturation of porcine cumulus cell-oocyte complexes (COCs). Concentrations of 0, 5, 50, and 500 nM 9-cis retinoic acid were added to the in vitro maturation medium, and the embryos were assessed after parthenogenetic activation. Cumulus cells and oocytes from the in vitro matured COCs were separated and subjected to RT-PCR and real-time RT-PCR for detecting retinoic acid receptors and measuring expression of prostaglandin-endoperoxide synthase1 and 2. The addition of 5 nM 9-cis retinoic acid to the maturation medium was beneficial for parthenogenetic embryo production. The effect of 9-cis retinoic acid was exerted directly through the oocytes via the retinoic acid receptor alpha and retinoid X receptor gamma signaling pathways and indirectly through the cumulus cells by the retinoic acid receptor beta and gamma and retinoid X receptor alpha and beta signaling pathways. The addition of 5 nM 9-cis retinoic acid-stimulated cumulus cells reaches full expansion by suppressing their excessive expression of prostaglandin-endoperoxide synthase 2. This study shows that 9-cis retinoic acid can exert its beneficial effect on parthenogenetic embryo production in pigs by multidimensional pathways affecting oocyte maturation.

trans‐10, cis‐12 conjugated linoleic acid enhances in vitro maturation of porcine oocytes

“…t10c12 CLA has also been shown to exert its regulatory function on COX2 levels in a number of cell types (Stachowska et al, ; Jiang et al, ; May et al, ). The results of the present study were the first indication of a pattern of COX2 protein expression during the maturation of porcine COCs, which was similar to the previous studies by detection of COX2 mRNA levels (Atikuzzaman et al, ; Yamashita et al, ). Moreover, we found that t10c12 CLA could increase COX2 protein levels in COCs compared to the control group, and that COX2 abundance within COCs was modulated according to culture conditions during maturation, which were associated with the concentrations of PGE2 and PGF 2α in maturation medium (Nuttinck et al, ).…”

Effect of co‐culture human endothelial progenitor cells with porcine oocytes during maturation and subsequent embryo development of parthenotes in vitro

“…In regard to the physiology of oocyte maturation in vivo, follicular somatic cell compartments, including the granulosa cells and cumulus cells surrounding oocytes, affect the meiotic resumption of oocytes (Atikuzzaman et al, ). It is well known that expansion of the cumulus cell layers initiates the maturation of oocytes by regulating expansion‐related genes including HAS2 , PTX3 , TNFAIP6 , and PTGS2 (Dragovic et al, ; Li et al, ; Prochazka, Nemcova, Nagyova, & Kanka, ).…”

All‐trans retinoic acid improves goat oocyte nuclear maturation and reduces apoptotic cumulus cells during in vitro maturation

“…The extent of COC maturation was assessed by microscopic examination using the cumulus cells expansion index (CCEI) scoring system (0 to 4+) according to Vanderhyden et al (1990) and Atikuzzaman et al (2011). In brief, a score of 0 indicates no detectable response, while 1+ indicates the minimum observable response, that is, cumulus cells having a glistening appearance, and 4+ indicates the maximum degree of expansion, that is, the cumulus oophorus exhibits full expansion and the innermost corona radiata layer is clearly visible.…”