Inhibition of miR-152 During in Vitro Maturation Enhances the Developmental Potential of Porcine Embryos

Abstract Background Oocyte developmental competence is regulated by various mechanisms and molecules including microRNAs (miRNAs). However, the functions of many of these miRNAs in oocyte and embryo development are still unclear. In this study, we managed to manipulate the expression level of miR-152 during oocyte maturation to figure out its potential role in determining the developmental competence of porcine oocytes.Results The inhibition of miR-152 during oocyte maturation does not affect the MII and cleavage rates, however it significantly enhances the blastocyst rate compared to the mimic and control groups. Pathway analysis identified several signaling pathways (including PI3K/AKT, TGFβ, Hippo, FoxO, and Wnt signaling) that are enriched in the predicted target genes of miR-152. Gene expression analysis revealed that IGF1 was significantly up-regulated in the inhibitor group and downregulated in the mimic group of oocytes. Moreover, IGF1R was significantly upregulated in the inhibitor group compared to the control one and IGFBP6 was downregulated in the inhibitor group compared to the other groups. Blastocysts developed from the mimic-treated oocytes exhibited an increase in miR-152 expression, dysregulation in some quality-related genes, and the lowest rate of blastocyst formation. Conclusions Our results demonstrate a negative correlation between miR-152 expression level and blastocyst rate in pigs. This correlation could be through targeting IGF system components during oocyte development.