Transcriptomic profile of the porcine oviductal epithelial cells during the peri-conceptional period.

The optimal environment in the oviduct is created by adjusting its ultrastructure and secretory activity to serve the most suitable protection of gametes and to support embryo development. Through gametes/embryo's presence inside the oviduct, the oviductal transcriptomic profile may be altered, and these changes may be caused by DNA methylation. The results of the present study documented that in the epithelial cells of the ampulla and isthmus of the oviducts collected from pigs during the peri-conceptional period, the most differentially expressed genes (DEGs) were down-regulated. Identified DEGs were classified into gene ontology categories as well as annotated into different biological pathways. From evaluated DEGs, genes important for embryo development were selected and the level of DNA methylation was determined. It was documented CLDN18, MUC1, CYP19A3, SOCS1, and ESR1 methylation level have been altered. The presence of embryos in the oviduct changed the transcriptomic profile and the level of DNA methylation in the epithelial cells of ampulla and isthmus during the peri-conceptional period.

Peri-conceptional under-nutrition alters transcriptomic profile in the endometrium during the peri-implantation period-The study in domestic pigs.

Female under-nutrition during early pregnancy may affect the physiological pattern of the transcriptomic profile in the endometrium. We aimed to determine if restricted diet applied to females during peri-conceptional period, that is, from the onset of the oestrus until day nine of pregnancy, alters transcriptomic profile in the endometrium during the peri-implantation period. The restricted diet gilts were fed forage, in which the dose of proteins and energy had been reduced by 30% compared to normal diet. Microarray analysis revealed that approximately 4% of transcripts, that is 1690 of 43803 probes from The Porcine (V2) Gene Expression Microarray 4 × 44 (Agilent Technologies, Santa Clara, CA, USA) were consistently altered (p ≤ .05) in the endometrium harvested from pigs fed restricted diet. In pigs fed restricted diet out of 1690 genes, 714 genes were upregulated and 976 genes were downregulated versus in pigs fed normal diet. From 1690 genes, 510 (30%) were genes with known biological functions in the KEGG database. The proportions of the differentially expressed transcripts were organized into six major categories and 39 subcategories containing 259 pathways associated with the differentially expressed genes. The largest amount of differentially expressed genes was involved in metabolism category. The most relevant genes were involved in gene ontology (GO) cellular component (CC) term. These findings suggest that females under-nutrition during peri-conceptional period may create changes in endometrial transcriptome during the peri-implantation period creating the potential changes in physiological functions of peri-implantation endometrium.

Interleukin-1ß system in the oviducts of pigs during the oestrous cycle and early pregnancy.

Interleukin-1ß (IL-1ß) acts throughout the IL-1ß system, which contains IL-1ß and the IL-1ß receptor (IL-1R), accessory protein (IL-1RacP), and receptor antagonist (IL-1Ra). In pigs, the expression of the members of the IL-1ß system was documented in uterine tissues during the oestrous cycle and early pregnancy, as well as in embryos harvested during the peri-implantation period. In the oviducts of non-gravid and gravid pigs, the expression of the IL-1ß system is unknown. Thus, in this study, the expression of the IL-1ß system was examined in porcine oviducts harvested on days 2-3 to 18-20 of the oestrous cycle and on days 2-3 to 15-16 of pregnancy. The expression of IL-1ß, IL-1R and IL-1RacP mRNAs in oviducts increased during the mid-luteal phase of the oestrous cycle, whereas the expression of IL-1Ra mRNA increased only during the early luteal phase, e.g., on days 2-3 of the oestrous cycle. Low expression of IL-1ß and IL-1Ra mRNAs was observed during the follicular phase of the oestrous cycle. In gravid pigs, the expression of IL-1ß, IL-1Ra and IL-1R mRNAs decreased (P < 0.05) from days 2-3 to 15-16 of pregnancy, whereas IL-1RacP mRNA expression did not change in pregnant pigs (P > 0.05). Significantly greater expression of the IL-1ß system mRNAs was demonstrated in oviducts harvested on days 2-3 of pregnancy vs. the respective days of the oestrous cycle. On days 2-3 of pregnancy, compared to respective days of the oestrous cycle, the quantity of IL-1ß protein was decreased (P < 0.05) in the ampulla and isthmus, while the quantity of IL-1Ra (only in the ampulla) and IL-1RacP proteins (in the ampulla and isthmus) were increased. The concentration of IL-1ß in oviductal flushings did not change (P > 0.05) in non-pregnant pigs, and it was greater (P < 0.05) on days 2-3 of pregnancy vs. the respective days of the oestrous cycle. Therefore, the presence of embryos in oviducts on days 2-3 after mating may influence the oviductal expression of the members of the IL-1ß system, determining the action of IL-1ß, which may be considered to be the earliest sign of pregnancy in pigs.

Periconceptional undernutrition affects in utero methyltransferase expression and steroid hormone concentrations in uterine flushings and blood plasma during the peri-implantation period in domestic pigs.

Female undernutrition during early pregnancy may affect the physiological pattern of genomic DNA methylation. We hypothesised that in utero DNA methylation may be impaired in females fed a restrictive diet in early pregnancy. In this study we evaluated whether poor maternal nutritional status, induced by applying a restricted diet during the peri-conceptional period, may influence: (1) the potential for in utero DNA methylation, expressed as changes in the mRNA expression and protein abundance of methyltransferases: DNA methyltransferase 1 (DNMT1) and DNMT3a in the endometrium and the myometrium, (2) the intrauterine microenvironment, measured as oestradiol 17ß (E2) and progesterone (P4) concentrations in uterine flushings and (3) plasma concentration of E2 and P4 during the peri-implantation period. Our results indicate that maternal peri-conceptional undernutrition affects maintenance and de novo DNA methylation in the endometrium, de novo methylation in the myometrium and a results in a decrease in intrauterine E2 concentration during the peri-implantation period. The intrauterine concentration of P4 and plasma concentrations of E2 and P4 did not change. These findings suggest that undernutrition during the earliest period of pregnancy, and perhaps the pre-pregnancy period, may create changes in epigenetic mechanisms in the uterus and intrauterine milieu of E2 during the peri-implantation period.

Expression and immunolocalization of membrane progesterone receptors in the bovine oviduct.

The oviduct plays a crucial role in the transport and maturation of gametes and ensures suitable conditions for fertility and early embryo development. One regulator of oviduct function is progesterone (P4), which affects the cell by interacting with nuclear progesterone receptors (PGRs) and through nongenomic mechanisms, presumably involving membrane PGRs. The aim of this study was to evaluate the expression of messenger RNAS (mRNAs) and proteins for progesterone receptor membrane component (PGRMC) 1 and 2 and membrane progestin receptors (mPR) α, ß, and γ and to use immunohistochemistry to demonstrate their cell-specific localization in the bovine oviduct. Oviducts ipsilateral and contralateral to the corpus luteum or to the dominant follicle were collected from cows on days 6 to 12 (midluteal stage) and 18 to 20 (follicular stage) of the estrous cycle and divided into 3 parts (infundibulum, ampulla, and isthmus). There were no differences (P > 0.05) in the PGRMC1, PGRMC2, mPRα, ß, and γ mRNA expression between ipsi- and contralateral oviducts. However, the same parts of the oviduct collected during the different stages of the estrous cycle showed higher (P < 0.05) mRNA levels of PGRMC1, PGRMC2, and mPRα on days 18 to 20 than on days 6 to 12 of the estrous cycle. mPRα and mPRß mRNA levels were higher (P < 0.05) in the infundibulum than in the isthmus, whereas PGRMC1 expression was higher (P < 0.05) in the infundibulum than in ampulla. Immunohistochemistry was used to detect PGRMC1, PGRMC2, PRα, ß, and γ proteins in all parts of both oviducts from days 6 to 12 and 18 to 20 of the estrous cycle. There were no differences in the staining intensity and cellular localization of the studied proteins between the ipsi- and contralateral oviducts and between the studied stages of the estrous cycle. A strong positive reaction was observed in luminal cells, but this reaction was less evident in myocytes and stromal cells. All proteins were also localized to the endothelial cells of blood vessels. These results suggest that membrane progesterone receptors, may be involved in the regulation of oviduct motility, secretory function, and blood flow in this organ.