Orexin B affects the transcriptome of incubated in vitro porcine endometrial explants from the early-implantation period

The effect of prostaglandins E2 and F2α on orexin system expression in the porcine uterus during the peri-implantation period

The aim of this study was to evaluate the effect of prostaglandins E2 (PGE2) and F2α (PGF2α) on orexins (OXA and OXB) secretion (ELISA), prepro-orexin (PPO) gene expression and the content of orexin receptors (OX1R, OX2R) mRNA (qPCR) and proteins (Western blot) in porcine endometrial and myometrial tissue slices during early pregnancy (days 10–28) and on days 10–11 of the oestrous cycle. On days 10–11 of pregnancy, prostaglandins (PGs) decreased the expression of the PPO gene and OXR gene and protein in the endometrium. On days 12– 13, PGs increased OXB secretion, PGE2 enhanced OXA secretion, and PGF2α suppressed PPO expression. On days 15–16, both PGs inhibited PPO expression and OXB secretion, and PGF2α increased OXA release. On days 27–28, PGs decreased PPO mRNA and OX1R protein levels, PGE2 decreased OX2R protein content, and PGF2α decreased OXB secretion. On days 10-11 of the cycle PGs increased the expression of PPO mRNA and OX2R protein, whereas PGE2 increased OX1R protein content. The effect of PGs on orexin system expression in the porcine myometrium was dependent on the animal physiological status and the concentrations of specific PGs. The study demonstrated that PGs exert regulatory effects on orexin system expression in the porcine uterus, which suggests that a local regulatory mechanism could be responsible for modulating uterine metabolism. The observed differences in PGs’ influence on orexin system expression could be attributed to changes in the sensitivity of the studied tissues, associated with the phase of the oestrous cycle, the stage of early pregnancy or PGs concentration.

Chemerin Effect on the Endometrial Proteome of the Domestic Pig during Implantation Obtained by LC-MS/MS Analysis

Chemerin (CHEM) is a hormone mainly expressed in adipocytes involved in the regulation of energy homeostasis and inflammatory response. CHEM expression has been demonstrated in the structures of the porcine hypothalamic-pituitary-gonadal axis, as well as in the uterus, trophoblasts and conceptuses of pigs. In this study, we performed high-throughput proteomic analyses (liquid chromatography with tandem mass spectrometry, LC-MS/MS) to examine the influence of CHEM (400 ng/mL) on differentially regulated proteins (DRPs) in the porcine endometrial tissue explants during implantation (15 to 16 days of gestation). Among all 352 DRPs, 164 were up-regulated and 188 were down-regulated in CHEM-treated group. DRPs were assigned to 47 gene ontology (GO) terms (p-adjusted < 0.05). Validation of four DRPs (IFIT5, TGFβ1, ACO1 and PGRMC1) by Western blot analysis confirmed the veracity and accuracy of the LC-MS/MS method used in the present study. We suggest that CHEM, by modulating various protein expressions, takes part in the endometrial cell proliferation, migration and invasion at the time of implantation. It also regulates the endometrial immune response, sensitivity to P4 and the formation of new blood vessels. Additionally, CHEM appears to be an important factor involved in endothelial cell dysfunction during the pathogenesis of preeclampsia. The identification of a large number of DRPs under the influence of CHEM provides a valuable resource for understanding the molecular mechanisms of this hormone action during implantation, which is a prerequisite for better control of pig reproduction.