Zearalenone Blocks Autophagy Flow and Induces Cell Apoptosis During Embryo Implantation in Gilts.

Zearalenone (ZEA) has been proved to be toxic, particularly to the reproductive system of gilts. The effect of ZEA on gilts during embryo implantation window period is of particular interests. Here, we observed window stage dysontogenesis of gilts treated with ZEA. In endometrial tissues and cells, autophagosomes increased significantly and mitochondria were damaged with increasing ZEA concentration. Addition of autophagy inhibitor confirmed that ZEA blocks the autophagic flow in the fusion of autophagosomes and lysosomes. In conclusion, ZEA exposure during embryo implantation results in endometrium inflammation by activating autophagy while blocking autophagy flow at the same time, leading to the significant accumulation of autophagosomes. The aforementioned effects of ZEA induce the apoptosis of primary endometrial cells through the caspase3 pathway, which would break the uterus environment balance and finally lead to embryo implantation failure and dysontogenesis in gilts.

mRNA/lncRNA expression patterns and the function of fibrinogen-like protein 2 in Meishan pig endometrium during the preimplantation phases.

Embryonic implantation involves a complex and well-coordinated interaction between the developing conceptus and maternal uterus, and the preimplantation period has a major impact on litter size in pigs. The present study aimed to investigate the vital messenger RNAs (mRNAs) and long noncoding RNAs (lncRNAs) that regulate preimplantation in Meishan pigs. The enriched Gene Ontology terms were all related to "binding." Furthermore, "ECM-receptor interaction" was predicted as an important pathway that regulated the success of implantation. We speculated that the differentially expressed mRNAs S100A9, ANXA8, MUC16, and FGL2 and the differentially expressed lncRNAs TCONS_11206566, TCONS_09904861, and TCONS_1252933 may play vital roles in the process of implantation. Furthermore, this study verified that FGL2 was highly expressed on Day 12 of pregnancy, and we also investigated the function of FGL2 during preimplantation in vivo. In conclusion, this study provides useful information for further analyses of the molecular mechanisms of implantation in Chinese domestic pigs.

Sequence analysis of microRNAs during pre-implantation between Meishan and Yorkshire pigs.

Embryonic implantation in sows is a coordinated interaction between the implantation-competent blastocyst and receptive uterus. In addition, microRNAs are small endogenous non-coding RNAs which are involved in post-transcriptional gene regulation of several biological processes including embryonic implantation. However, the mechanisms of miRNAs involved in embryonic implantation of sows remain largely unknown. Here, we analyzed miRNAome of endometrium on day 9, 12 and 15 of pregnancy and on day 12 of non-pregnancy in Meishan and Yorkshire pigs by Illumina sequencing. From 24 libraries, we identified 312 known microRNAs and 211 potential novel miRNAs. Bioinformatics analysis showed that differentially expressed microRNAs on day 12 of pregnancy between the two breeds may play critical roles by involving "p53 signaling pathway" and "Wnt signaling pathway". Furthermore, our results demonstrated that ssc-miR-21, ssc-miR-451, ssc-miR-204, ssc-miR-199a-5p and ssc-miR-199b-5p would play crucial roles for implantation. The data generated in this study were expected to elucidate the influence of microRNAs during pre-implantation in pigs.

Identification of non-coding and coding RNAs in porcine endometrium.

One of the most critical periods of embryonic loss in pig is day 12 of pregnancy, when implantation begins. Here, we analyzed the gene expression on day 12 of pregnancy and non-pregnancy in the porcine endometrium using RNA sequencing (RNA-seq). 237 mRNAs, 34 lncRNAs and 1 miRNA were significantly differentially expressed between the two groups. Further functional analyses were conducted to identify these differentially expressed transcripts. The results demonstrated that they participate in various biological processes, such as cell adhesion, binding, nucleic and metabolic processes. In addition, our results showed that the differentially expressed genes (IL1R, FGF9, DUPS10, DUPS4, CD14 and MAP4K4) in MAPK pathway, and lncRNAs of XLOC_2604764 and XLOC_2604756 may play a vital role in regulating embryo implantation. Besides, we investigated the lncRNA-ssc-miR-132-mRNA interactions, aiming to explain the regulatory networks of coding and non-coding genes that contributes to the establishment of the maternal pregnancy.