Evaluating the Sheep Oocyte In Vitro Developmental Competence and Expression of MicrorRNAs in Cumulus Cells in Response to Inflammatory Effects Induced by Lipopolysaccharide

This study was conducted to investigate the influence of lipopolysaccharide (LPS) on sheep oocyte maturation and developmental competence and changes in the expression of microRNAs in cumulus cells in the inflammatory situations induced by LPS. For this, ewechr('39')s oocytes were cultured in medium containing 0 (control) and 1 µg/ml of LPS for 24 hours. After in vitro maturation, the percentage of nucleus maturation and distribution of cumulus cells were evaluated. Moreover, the rate of cleavage and blastocyst production were evaluated. The expression of microRNAs was quantitatively assessed by real-time PCR. The addition of LPS to maturation medium did not show any significant effects on the proportion of nucleus maturation and cumulus cell distribution. Although percentage of cleavage was not affected by LPS, the rate of blastocyst production was significantly reduced in the presence of LPS (P < 0.05). Expression of Mir-150 was significantly increased in response to LPS supplementation in culture medium (P < 0.05). Also, the expression of Mir-200b and Mir-27a increased in culture medium containing LPS compering to the control group, whereas Mir-let7a expression decreased in response to LPS addition, however, the difference was not statistically significant. The results demonstrate that LPS has detrimental effects on sheep oocyte developmental competence and these effects seem to be mediated through changes in the expression of microRNAs in cumulus cells.