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Most in vitro models of oviduct epithelial cells (OEC) used thus far to gain insights into embryo-maternal communication induce cell dedifferentiation or are technically challenging. Moreover, although the presence of developing embryos has been shown to alter gene expression in OEC, the effect of embryos on OEC physiology remains largely unknown. Here, we propose a model based on bovine oviduct epithelial spheroids (OES) with specific shape and diameter (100-200 μm) criteria. The aims of this study were to i) determine the appropriate culture conditions of bovine OES cultured in suspension by evaluating their morphology, total cell number, viability, and activity of ciliated cells; ii) monitor gene expression in OES at the time of their formation (day 0) and over the 10 days of culture; and iii) test whether the vicinity of developing embryos affects OES quality criteria. On day 10, the proportions of vesicle-shaped OES (V-OES) were higher in M199/500 (500 μl of HEPES-buffered TCM-199) and synthetic oviduct fluid (SOF)/25 (25-μL droplet of SOF medium under mineral oil) than in M199/25 (25-μL droplet of M199 under mineral oil). The proportion of viable cells in V-OES was not affected by culture conditions and remained high (>80%) through day 10. The total number of cells per V-OES decreased over time except in SOF/25, while the proportions of ciliated cells increased over time in M199/500 but decreased in M199/25 and SOF/25. The movement amplitude of OES in suspension decreased over time under all culture conditions. Moreover, the gene expression of ANXA1, ESR1, HSPA8, and HSPA1A in OES remained stable during culture, while that of PGR and OVGP1 decreased from day 0 to day 10. Last, the co-culture of developing embryos with OES in SOF/25 increased the rates of blastocysts on days 7 and 8 compared to embryos cultured alone, and increased the proportion of V-OES compared to OES cultured alone. In conclusion, M199/500 and SOF/25 provided the optimal conditions for the long-time culture of OES. The supporting effect of OES on embryo development and of developing embryos on OES morphology was evidenced for the first time. Altogether, these results point OES as an easy-to-use, standardizable, and physiological model to study embryo-maternal interactions in cattle., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024. Published by Elsevier Inc.)

Progesterone is pivotal to maintain pregnancy in the first trimester and low concentration (<4 ng/mL) has been associated with early pregnancy loss. Measurement of progesterone is widely used in practice to determine whether a mare needs progestin supplementation. Therefore, the objective of the present study was to determine progesterone concentration and the luteal tissue area in mares non-bred, and those bred becoming pregnant, and those failing to become pregnant. We hypothesized that pregnant mares have greater progesterone concentration than non-pregnant mares. Fifty-two cycles of mares (n = 14) were monitored by ultrasonography every other day until detection of a pre-ovulatory follicle. Then deslorelin acetate was administered to induce ovulation. Twenty-four hours later, mares were bred (∼2 billion progressively motile sperm extended in 50 mL; n = 37 cycles) or a sham-bred (50 mL of extender; n = 15 cycles). Ovulation was confirmed and number of corpora lutea and the luteal tissue area were recorded daily until 10-days post-ovulation. Progesterone concentration was assessed daily from the day of the ovulation up to 10-days post-ovulation. Pregnancy diagnosis was carried out at 10- and 13-days post-ovulation. Of the bred mares, 20 of them became pregnant and 17 did not. Data were analyzed with a mixed model, Tukey's test as post-hoc, and Pearson's coefficient of correlation. Progesterone concentration and luteal tissue area varied with time (P = .001) but not with group (P > .05). Multiple ovulations were associated with greater progesterone concentration and luteal tissue area (P = .0001). There was a moderate positive association between the number of ovulations and luteal tissue area (r = 0.54; P = .0001). The lack of change in the progesterone concentration and luteal tissue area between bred and non-bred mares suggests that horse seminal plasma does not affect luteal function in mares. As all mares had progesterone above 4 ng/mL after 5-days post-ovulation; it is possible that if mares with abnormal progesterone concentration were used, the results could have been different. In conclusion, pregnancy was not associated with greater progesterone concentration or luteal tissue area., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Extracellular vesicles (EVs) have emerged as novel cell-to-cell communication mediators in physiological and pathological scenarios. Their ability to transfer their molecular cargo (RNAs, proteins and lipids) from one cell to another, in the vicinity or far from the cell of origin, together with their capacity of exerting a functional impact on the target cell make them valuable diagnostic tools as well as therapeutic vectors in a variety of diseases. In the reproductive field, there is a growing interest in the role of EVs in gamete/embryo-maternal communication and their potential implications in the reproductive success. In this review, we provide current knowledge of EVs secreted by the oviduct (oEVs) and embryos (eEVs), since both have been proposed as key players in the crucial two-way dialogue between the oviduct (lining epithelium and secretions) and the embryo that ensures successful pregnancy. Both oEVs and eEVs molecular cargos and their potential role as multi-signal messengers in the gametes/embryo-oviduct cross-talk and in the embryo-to-embryo communication in different species are also addressed. Eventually, a comparative analysis between oEVs and eEVs has been performed to shed some light on common and specific cargos responsible for their functions supporting the early reproductive events and as prime candidate molecules for improving fertility and assisted reproductive technologies outcomes., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2020.)

Intrauterine growth restriction (IUGR) is a serious pregnancy complication caused by placental insufficiency. We previously reported that truncation of MIMT1 gene exons 3 and 4 (MIMT1 Del ) causes IUGR in cattle. Here we investigated miRNA expression in the foetal and maternal placenta tissues of MIMT1 Del/WT foetuses. Small RNA next generation sequencing and quantitative PCR revealed placental tissue-specific expression of the miR-4321, known to regulate many genes involved in early foetal development. This study also indicated that maternal and foetal components of the placenta respond differently to a deleterious conceptus mutation., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

In cows, retained fetal membranes (RFM) are a major problem in reproduction. The timely detachment of fetal membranes after parturition requires well coordinated maturation processes in the placenta. One feature of placental maturation in cows is a prepartal decline in the number of binucleate trophoblast giant cells (BNC) in the fetal chorion. Pregnancy associated glycoproteins (PAGs) are a group of proteins, produced by trophoblast cells in artiodactyls. We studied aspects of PAG expression in cows with and without RFM. The numerical density of PAG-positive immunostained BNC in placentomal samples, collected from cows with normal expulsion of fetal membranes (n = 20) and cows with RFM (n = 20) was determined. The number of PAG-positive BNCs was significantly higher in cows with RFM, compared to controls. The concentration of PAGs in maternal serum in prepartum, intrapartum, and postpartum cows was measured (RFM n = 20; controls n = 68). No significant differences between RFM and controls were detected. Microarray analysis of placental PAG mRNA expression was done with two types of microarrays: Affymetrix (RFM n = 20; controls n = 20) and Agilent (RFM n = 8; controls n = 8). Both microarrays showed a significantly higher expression of modern PAGs in RFM cases. Our results show that the expression of modern PAGs, which are produced by BNCs and are secreted into the maternal organism, are differentially expressed in RFM. Although the concentration in peripheral maternal blood did not differ between RFM and controls, the local concentration in the placenta is likely to be higher in RFM cases. This suggests the possibility of local regulatory roles of PAG in the release of bovine fetal membranes., (Copyright © 2017. Published by Elsevier Inc.)

Background: MicroRNAs (miRNAs) regulate several aspects of the morphogenesis and homeostasis of the skin and its appendages, and miRNA deregulation has been shown to be associated or even causally related to several skin diseases., Objective: To evaluate the differential expression of miRNAs during sebaceous lipogenesis., Methods: Inhibition of global miRNA activity in human SZ95 sebaceous gland cells was achieved by transfection with siRNAs directed against the DICER transcript, encoding a key enzyme of miRNA biogenesis. Sebaceous lipogenesis was induced in SZ95 sebocytes by addition of linoleic acid (LA) and ciglitazone (CIG) and microarray-based miRNA expression profiles were obtained on an Agilent platform. The expression of selected miRNA candidates was measured by Taqman quantitative real-time RT-PCR. Increased activity of one validated miRNA was attained by transfecting SZ95 sebocytes with miR-574-3p mimics., Results: Downregulation of sebaceous lipogenesis was detected in DICER-impaired SZ95 sebocytes. Using microarrays, we identified twelve significantly upregulated and nine significantly downregulated miRNAs in LA- and CIG-treated SZ95 sebocytes as compared to non-treated cells. Validation of a subset of miRNA candidates by qRT-PCR confirmed upregulation of mIR-203 and miR-574-3p and downregulation of miR-7 during sebaceous lipogenesis. The two upregulated miRNAs have been previously implied in keratinocyte differentiation. Increased activity of miR-574-3p augmented lipogenesis in SZ95 sebocytes., Conclusion: Global miRNA activity is essential for lipid synthesis in human SZ95 sebocytes. Individual miRNAs are likely to play a significant role during sebaceous lipogenesis., (Copyright © 2013 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.)