PGF2α Secretion Research Articles

Noradrenaline and adrenoreceptors regulate prostaglandin F2A formation in endometrium after experimentally-induced inf lammation in the pig

Abstract Endometritis is the most common pathology in animals. However, in the context of an inflamed endometrium, alterations occur in the production of prostaglandins (PG s) and the noradrenergic innervation of the uterus, although the precise relationship between noradrenaline (NA), adrenoreceptors (AR s), and the output of PG F2α remains unclear. To clarify this issue, the participation of α1-, α2- and β-AR s in NA-influenced PG F synthase (PG FS) and PG 9-ketoreductase/carbonyl reductase (CBR1) protein abundances in the porcine inflamed endometrium, and the secretion of PG F2α from the tissue were determined. E. coli suspension (E. coli group) or saline (CO N group) was injected into the uterine horns. After eight days, severe acute endometritis was diagnosed in the E. coli group. Endometrial explants were treated with NA and/or α1-, α2- and β-AR s antagonists. In the CO N and E. coli groups, NA increased endometrial PG FS and CBR1 protein abundances and PG F2α secretion, compared to the control values (obtained from an endometrium that had not undergone any in vitro treatment). In the E. coli group, NA-stimulated CBR1 protein abundance and PG F2α release were higher, while PG FS protein abundance was lower than in the CO N group. In the latter group, the antagonists of α1A-, α1D-, α2B- and α2C-AR s isoforms and β2- AR s subtype decreased NA-stimulated PG FS protein abundances, compared to NA action alone. In the E. coli group, this effect on PG FS abundances evoked α1D-, α2C-, β1- and β2-AR s antagonists with NA. Antagonists of α1B-, α2B-, β1- and β2-AR s in the CO N group and antagonists of α1B-, α1D-, α2A-, α2C-, β1- and β2-AR s in the E. coli group eliminated a rise in the NA-stimulated CBR1 abundance of protein versus the NA influence alone. In comparison to NA effect alone, α1D-, α2C- and β2-AR s antagonists with NA reduced PG F2α secretion in both the CON and E. coli groups. Such effect on PG F2α release was also exerted in the E. coli group by α1B-, α2A- and β1-AR s antagonists with NA. Summarizing, in the porcine inflamed endometrium, NA increases PG FS protein abundance via α1D-, α2C- and β(1, 2)-AR s, and CBR1 protein abundance and PG F2α release by α1(B, D)-, α2(A, C) and β(1, 2)-AR s. The obtained findings suggest that, in an indirect manner, NA may affect the PG F2α-regulated processes by influencing its production and secretion. The results could offer new targets for drugs to regulate inflammation and improve uterine and ovarian functions.

YPEL3 Negatively Regulates Endometrial Function via the Wnt/β-Catenin Pathways during Early Pregnancy in Goats.

In ruminants, the establishment of pregnancy requires a series of structural and functional changes in the endometrium under the action of hormones, thereby providing an optimal environment for the implantation of the embryo. In this study, we explored the molecular mechanism by which YPEL3 regulates endometrial function during gestation in goats. We found YPEL3 expression was significantly downregulated during early gestation and that YPEL3 overexpression inhibited the expression of ISG15, but had no significant effects on the expression of RSAD2 and CXCL10 in goat endometrial epithelial cells (gEECs). In addition, YPEL3 silencing significantly inhibited PGF2α secretion and the expression of the prostaglandin synthesis-related rate-limiting enzyme-encoding genes PGFS and PTGES, with no significant effect on the expression of PTGS1 and PTGS2. Moreover, YPEL3 inhibited the expression of vimentin and β-catenin and pretreatment of gEECs with the β-catenin activator CHIR99021 prevented a YPEL3-induced decrease in vimentin expression. Collectively, our findings confirm that, as a hormone-regulated factor, YPEL3 regulates endometrial function by inhibiting the Wnt/β-catenin signaling pathway and provide new insights for further clarification of the mechanism by which YPEL3 functions during early pregnancy in ruminants.

Scopolamine administration in repeat breeder cows on the day of heat

Scopolamine is a parasympatholytic drug that can modulate uterine contractile activity. Based on the hypothesis that deficiency in uterine contractility is a cause of Repeat Breeder (RB) syndrome in cows, this study aimed to evaluate the efficacy of scopolamine administration in RB cows, on the day of heat, in increasing conception rates. Forty RB cows were randomly divided into treated group [T; 20 cows treated with scopolamine butylbromide 40 mg/100 kg of body weight (BW) by the intramuscular (IM) route after clinical confirmation of heat (T0)] and the control group [C; 20 cows treated with 2 mL/100 kg of BW of saline solution, IM, at T0]. Twelve hours later (T1), all of the cows were artificially inseminated (AI). Blood plasma-progesterone (P4), hydroxyproline, and prostaglandin F2α metabolite (PGFM), concentrations were assessed at T0 and T1. Additionally, the uterine tone was evaluated by transrectal palpation. Conception rates were recorded. Drug administration increased the conception rates in group T to 80% unlike group C (25%) (P < 0.0001). Higher PGFM concentration levels were registered in the treated group than in the control group. The higher PGF2α secretion in pregnant cows of the T group may have reduced the P4 levels, making conception possible. Scopolamine administration at the time of heat can improve uterine contractility. This makes it more suitable for promoting conception in RB cows, where hormonal alterations and contractile and biochemical deficits are responsible for the syndrome.

Expressions of ghrelin and GHSR-1a in the corpus luteum and the stimulatory effect of ghrelin on luteal function of pregnant sows

Studies have shown that ghrelin played direct actions in ovarian function, but the direct role of ghrelin in corpus luteum (CL) of pregnant sows has remained obscure. The study aimed to examine the expressions of ghrelin and its functional receptor (GHSR-1a) in the CL of sows during pregnancy, and evaluate the role of ghrelin in CL function of pregnant sows. Immunohistochemistry analysis showed that ghrelin and GHSR-1a are both predominantly localized in the luteal cells of pregnant sows CL. Strong immunoreactivity for ghrelin and GHSR-1a is detected at days 20 (early) and 50 (middle), but weak immunoreactivity is observed at days 90 (late) post mating. Similarly, there is a significant effect of pregnant phase on the expression (mRNA and protein) of ghrelin and GHSR-1a in the CL, with higher levels at days 20 (early) and 50 (middle), and lower values at 90 (late) post mating. In vitro, treatments of luteal cells with ghrelin (from 0.01 to 10 ng/mL) are promoted cell viability and P4 secretion in a dose-dependent manner. Ghrelin is also accelerated the LH-induced P4 secretion in luteal cells. Moreover, ghrelin is induced the release and mRNA expression of LH, and increased the release of prostaglandin (PG)E2, but reduced the secretion of PGF2α in luteal cells. In conclusion, the presences of ghrelin and GHSR-1a in the porcine CL during pregnancy, and the stimulatory effect of ghrelin on luteal cells suggest positive regulation by ghrelin in CL function of pregnant sows.

Effects of orexin A on PTGS2, PTGES, CBR1 and PGFS mRNA transcript abundances and prostaglandin E2 and F2α concentrations in culture medium of pig uterine explants collected during early gestation and the estrogenic cycle

In this study, aims were to evaluate orexin A (OXA) effects on mRNA abundance of important enzymes involved in prostaglandin production, such as cyclooxygenase 2 (PTGS2), microsomal PGE2 synthase-1 (PTGES), PGF2α synthase (PGFS) and carbonyl reductase 1 (CBR1), as well as prostaglandin E2 (PGE2) and F2α (PGF2α) culture medium concentrations for endometrial and myometrial explants. Tissues were collected from gilts during specific phases of the estrogenic cycle or early gestational period. There were greater concentrations of PGE2 with OXA treatments of endometrial tissues collected on days 12–13 and 27–28, as well as PGF2α on days 10–11 of the gestational period. The PGF2α concentrations were less in tissues collected on days 27–28 of the gestational period. The OXA treatments resulted in lesser concentrations of PGE2 from myometrial tissues collected on days 10–11 and greater PGF2α on days 10–11 of the gestational period and 10–11 of the estrogenic cycle. Effects of OXA may occur due to actions at PTGS2, PTGES, PGFS and CBR1 genes because mRNA abundances for proteins encoded by these genes were affected by OXA. Results indicate there is an OXA effect on mRNA abundances and prostaglandin culture medium concentrations of uterine tissue collected at different stages of the gestational period or estrogenic cycle using different doses of OXA. It, therefore, is concluded OXA may affect de novo synthesis and secretion of PGE2 and PGF2α in the uterus of pigs.

Inhibition of lipopolysaccharide-induced suppression of luteal function in isolated perfused bovine ovaries.

Recently, we observed that lipopolysaccharide (LPS) suppresses corpus luteum (CL) function in isolated perfused ovaries. It remained unclear if this suppression was due to increased luteal PGF2α secretion or LPS-induced apoptosis. Therefore, possible impacts of PGF2α and LPS were inhibited by a non-steroidal anti-inflammatory drug (flunixin) and an endotoxin-binding agent (polymyxin B), respectively. Bovine ovaries with a mid-cycle CL were collected immediately after slaughter and perfused for 240 min. After 50 min of equilibration, either flunixin or polymyxin B (5 μg/ml of each) were added to the perfusion medium of six ovaries, respectively. All ovaries (n = 12) were treated with E. coli LPS (0.5 μg/ml) 60 min after the onset of perfusion, and received 500 I.U. of hCG after 210 min of perfusion. Progesterone and PGF2α were measured in the effluent perfusate every 10 and 30 min, respectively. Biopsies of the CL were collected every 60 min to determine the mRNA expression of the cytokine TNFA and factors of apoptosis (CASP3, -8). Flunixin-treatment inhibited the increase of PGF2α after LPS-challenge that was observed in the polymyxin B-treated (PX-LPS) ovaries. After hCG-stimulation, progesterone secretion increased (P < 0.05) in group PX-LPS but not in the flunixin-treated (F-LPS) ovaries. Compared to initial values before LPS-challenge, luteal mRNA expression of TNFA and CASP3 was increased (P < 0.05) in group F-LPS at 120 and 180 min, respectively, and those of CASP8 was decreased (P < 0.05) in PX-LPS at 60 and 120 min after LPS-treatment. In conclusion, although flunixin managed to inhibit PGF2α, it did not suffice to successfully prevent LPS-induced apoptosis. However, endotoxin-binding polymyxin B resulted in luteal responsiveness to hCG after LPS-challenge.

Effects of cortisol on prostaglandin F2α secretion and expression of genes involved in the arachidonic acid metabolic pathway in equine endometrium - In vitro study

Glucocorticoids (GCs) are known to play an important role in maintaining basal and stress-related homeostasis by interacting with endocrine mediators and prostaglandins (PGs). Although a growing body of evidence shows that GCs exert their regulatory action at a multitude of sites in the reproductive axis through corticosteroid receptors, little is known about the direct role of cortisol, an active form of GCs, in the equine endometrium. Thus, the study aimed to determine the effect of cortisol on PGF2α synthesis in the endometrial tissue and cells in vitro. In Exp.1, the immunolocalization and the expression of the glucocorticoid receptor (GCR) in the endometrium throughout the estrous cycle were established. In Exp. 2 and 3, the effects of cortisol on PGF2α secretion and transcripts associated with the arachidonic acid (AA) cascade in endometrial tissues, and cells were defined. Endometrial tissues obtained from the early, mid, and late luteal phases and the follicular phase of the estrous cycle were exposed to cortisol (100, 200, and 400 nM) for 24 h. Endometrial epithelial and stromal cells (early phase of estrous cycle) were exposed to cortisol (100 nM) for 24 h. Then, PGF2α secretion and transcripts associated with the AA cascade (PLA2G2A, PLA2G4A, PTGS2, and PGFS) were assessed. GCR was expressed in the cytoplasm and the nucleus in the luminal and glandular epithelium as well as in the stroma. Endometrial GCR protein abundance was up-regulated at the late luteal phase compared to the mid-luteal phase of the estrous cycle. Cortisol dose-dependently decreased PGF2α secretion, PLA2G2A and PLA2G4A transcripts in endometrial tissues. Additionally, cortisol treatment decreased PGF2α secretion from endometrial epithelial and stromal cells. Moreover, it affected PLA2G2A, PLA2G4A, and PTGS2 transcripts in endometrial stromal cells. These findings suggest that cortisol suppresses the synthesis of PGF2α by affecting the AA cascade in the equine endometrium during the estrous cycle.

Chloroorganic (DDT) and organophosphate (malathion) insecticides impair the motor function of the bovine cervix

Dichlorodiphenyltrichloroethane (DDT) is a representative organochlorine insecticide and a known endocrine disruptor. Malathion is an organophosphate insecticide and a next-generation pesticide. Previously, it was shown that oxytocin (OT) and prostaglandins (PGs) are involved in the mechanism of the adverse effect of DDT on bovine myometrial contractions. However, disruption of myometrial contractions without disruption of cervical activity may not be sufficient to cause preterm delivery. Hence, the aim of this study was to determine the effects of insecticides on the function of the bovine cervix at preovulation period. Bovine cervical cells or strips were treated with DDT or malathion (0.1–100 ng/ml), and neither DDT nor malathion (each at a dose of 100 ng/ml) affected the viability of cervical cells. Malathion (0.1–10 ng/ml) and the high doses of DDT (10 ng/ml) decreased the force of cervical contractions, in contrast to a low dose of DDT (0.1 ng/ml). Both insecticides also decreased the mRNA expression of the OT receptor and the level of the second messenger (inositol triphosphate, IP3). Moreover, DDT decreased the amount of other second messengers (diacylglycerol, DAG), while malathion decreased the amount of gap junction protein (GAP). Only malathion increased PGE2 and decreased PGF2α secretion, while neither insecticide had an effect on both prostaglandins synthesis. Both DDT and malathion impaired cervical contractions, secretory function and cellular signalling. It is also possible that malathion-mediated induction of locally produced PGE2 can be followed by cervical softening. Admittedly it was shown that DDT and malathion can evoke failures in the regulation of motor function of cervix during oestrus cycle, while their harmful effect on gestation can be also not excluded.

Urocortins exhibit differential effects on PGE2 and PGF2α output via CRHR2 in human myometrium.

Urocortins (UCNs), belonging to corticotropin-releasing hormone (CRH) family, exert their function via CRH receptor type 1 (CRHR1) and 2 (CRHR2). Our previous studies have demonstrated that CRH acts on CRHR1 to potentiate prostaglandins (PGs) output induced by inflammatory stimuli in myometrial cells. In the present study, we sought to investigate the effects of UCNs on prostaglandin (PG) output via CRHR2 in cultured human uterine smooth muscle cells (HUSMCs) from pregnant women at term. We found that UCN and UCN 3 treatment promoted PGE2 and PGF2α secretion in a dose-dependent manner. In contrast, UCN2 dose-dependently inhibited PGE2 and PGF2α secretion. Their effects were reversed by CRHR2 antagonist and CRHR2 siRNA. Mechanically, we showed that UCN and UCN3 suppressed cAMP production and led to Gi activation while UCN2 stimulated cAMP production and activated Gs signaling. Further, UCN and UCN3 but not UCN2 activated NF-κB and MAPK signaling pathways through Gi signaling. UCN and UCN3 stimulation of PGs secretion were dependent on Gi/adenylyl cyclase (AC)/cAMP, NF-κB and MAPK signaling pathways. UCN2 suppression of PGs output was through Gs/AC/cAMP signaling pathways. Our data suggest that UCN, UCN2 and UCN3 can finely regulate PGs secretion via CRHR2, which facilitates the functional status of the uterus during pregnancy.

Heat stress influences the attenuation of prostaglandin synthesis by interferon tau in bovine endometrial cells

Heat stress (HS) reduces reproductive performance of cattle, possibly by disrupting endocrine regulation such as prostaglandin (PG) production from uterus and estradiol 17β production from the dominant follicle. Prostaglandin F2α (PGF2α) secretion from endometrium surges during the luteal phase due to tumor necrosis factor (TNF) α stimulation and a positive-feedback loop with oxytocin (OT) from the corpus luteum, ultimately triggering luteolysis, while interferon τ (IFNT) inhibits upregulation of PGF2α production by TNFα and OT, thereby preventing luteolysis and triggering recognition of pregnancy. In the present study, we investigated the effect of OT, TNFα, and IFNT on PGF2α production in both types of endometrial cells under HS conditions. Stimulation of PGF2α production in endometrial epithelial cells by OT was unaffected by HS, while stimulation of PGF2α production in endometrial stromal cells by TNFα was enhanced by HS, and this increased PGF2α production was not significantly suppressed by IFNT. These results suggest that HS disrupted the regulation of PGF2α production by TNFα and IFNT in bovine endometrial stromal cells and it might be one of causes for low conception rate of cattle in summer.

An integrated study of metabolomics and transcriptomics to reveal the anti-primary dysmenorrhea mechanism of Akebiae Fructus

Ethnopharmacological relevanceAkebiae Fructus, a Tujia minority folk medicine and a well-known traditional Chinese medicine for soothing the liver, regulating Qi, promoting blood circulation and relieving pain, is widely used in the treatment of primary dysmenorrhea. However, little is known about its underlying mechanism. Aim of the studyTo explore the effect of Akebiae Fructus on primary dysmenorrhea model induced by estradiol benzoate and oxytocin, and to provide better understanding of the mechanism of Akebiae Fructus for primary dysmenorrhea treatment. Materials and methodsThe primary dysmenorrhea mouse model was used in this study. Except for the control group and the normal administration group, the mice of other groups were subcutaneously injected with estradiol benzoate (10 mg/kg/d) for 10 consecutive days. From the 5th day of the ten-day model period, the positive control groups were given 0.075 g/kg ibuprofen and 7.5 g/kg Leonurus granule, the drug groups were given 0.2 g/kg, 0.4 g/kg, 0.8 g/kg Akebiae Fructus extract, the normal administration group was given 0.8 g/kg Akebiae Fructus extract, and the same volume saline was given in the control group. On the tenth day, oxytocin (10 U/kg) was peritoneally injected after estradiol benzoate injected 1 h. After the oxytocin injection, writhing behavior was observed for 30 min. Then the uterine tissue was collected to measure the level of PGF2α and PGE2, and for histological analysis and transcriptomics analysis. Meanwhile, plasma and urine samples were collected for metabolomic analysis. ResultsAkebiae Fructus inhibited the writhing, decreased the PGF2α level and ameliorated the morphological changes. 32 potential metabolic biomarkers in plasma and 17 in urine were found for primary dysmenorrhea, and after Akebiae Fructus treatment, 25 metabolites in plasma and 14 in urine were restored. These altered metabolites were mainly involved in lipid, amino acid and organic acid metabolism. For the transcriptomic study, a total of 2244 differentially expressed genes (1346 up-regulated and 898 down-regulated) were obtained between the control and model group, and 148 differentially expressed genes (DEGs) were found related with Akebiae Fructus treatment of primary dysmenorrhea. Correlation analysis was carried out based on the transcriptomic and metabolomic data. 5 differentially expressed genes (Plpp3, Sgpp2, Arg1, Adcy8, Ak5) were found related with the enrichment metabolic pathways. The mechanism by which Akebiae Fructus ameliorates primary dysmenorrhea may account for the regulation of the gene expression to control the key enzymes in the sphingolipid metabolism, arginine and proline metabolism, glycerophospholipid metabolism and purine metabolism, inhibiting the abnormal secretion of PGF2α, alleviating the uterine contraction and reducing inflammation and pain. ConclusionsAkebiae Fructus could effectively alleviate the symptoms of primary dysmenorrhea, regulate metabolic disorders, and control the related gene expression in primary dysmenorrhea. The study may provide clues for further study of Akebiae Fructus treatment on primary dysmenorrhea.

The role of vaspin in porcine corpus luteum.

Vaspin, visceral adipose tissue-derived serine protease inhibitor, plays important roles in inflammation, obesity, and glucose metabolism. Our recent research has shown the expression and role of vaspin in the function of ovarian follicles. However, whether vaspin regulates steroidogenesis and luteolysis in the corpus luteum (CL) is still unknown. The aim of this study was first to determine the expression of vaspin and its receptor GRP78 in porcine CL at the early, middle, and late stages of the luteal phase. Next, we investigated the hormonal regulation of vaspin levels in luteal cells in response to luteinizing hormone (LH), progesterone (P4), and prostaglandin PGE2 and PGF2α. Finally, we determined vaspin's direct impact on luteal cells steroidogenesis, luteolysis and kinases phosphorylation. Our results are the first to show higher vaspin/GRP78 expression in middle and late vs early stages; immunohistochemistry showed cytoplasmic vaspin/GRP78 localization in small and large luteal cells. In vitro, we found that LH, P4, PGE2, and PGF2α significantly decreased vaspin levels. Furthermore, vaspin stimulated steroidogenesis by the activation of the GRP78 receptor and protein kinase A (PKA). Also, vaspin increased the ratio of luteotropic PGE2 to luteolytic PGF2α secretion via GRP78 and mitogen-activated kinase (MAP3/1). Moreover, vaspin, in a dose-dependent manner, decreased GRP78 expression, while it, in a time-dependent manner, increased kinases PKA and MAPK3/1 phosphorylation. Taken together, we found that vaspin/GRP78 expression depends on the luteal phase stage and vaspin affects luteal cells endocrinology, indicating that vaspin is a new regulator of luteal cells steroidogenesis and CL formation.

The effect of DDE and dieldrin and their parental substances (DDT and aldrin) on PGE2 and PGF2α release from bovine endometrial explants collected during 120 to 180 days of the gestational period.

Dieldrin and DDE are environmental metabolites of the organochlorine pesticides aldrin and DDT, respectively. During pregnancy, these chemicals can quickly infiltrate through the placental barrier, accumulate in amniotic fluid and fetus, and act as endocrine disruptors (EDs). The aim of this study was to investigate the effect of DDE and dieldrin and their parental substances at concentrations of 1 and 10 ng/ml on secretion of PGE2 and PGF2α from bovine endometrial explants (120-150 and 151-180 days of pregnancy) after 24 hr of incubation with EDs. The mRNA expression of COX2, PGES and PGFS and the concentrations of PGE2 and PGF2α were measured. EDs did not affect (p>0.05) COX2 gene expression, but DDT and DDE decreased (p⟨0.05) PGES expression and PGE2 secretion in the explants from 120-150 days of pregnancy. Depending on the dose, DDT and DDE increased (p⟨0.05) PGFS expression and PGF2α secretion from the explants from 120-150 days and decreased PGF2α secretion (p⟨0.05) from the explants from 151-180 days of pregnancy. Aldrin and dieldrin decreased (p⟨0.05) PGFS expression and PGF2α secretion from all explants. In summary, EDs disrupt the secretion of PGE2 and PGF2α by influencing the gene expression of PGES and PGFS.

Review: Influences of non-steroidal anti-inflammatory drugs on dairy cattle reproductive performance

ABSTRACT Purpose Reproductive efficiency is an important contributor to a dairy farm’s profitability; however, there are many factors that influence reproductive success, including, but not limited to, embryonic loss. This review summarizes research findings related to the use of prostaglandin F2α (PGF2α) inhibitors to improve fertility in cattle. Sources Peered-reviewed literature and conference proceedings were reviewed in this article. Synthesis Approximately one-third of total embryonic loss occurs between d 8 and 27 after fertilization. Because of a large incidence of early embryonic loss in cattle, researchers have been searching for strategies to reduce the risk of embryonic loss. Provided that the embryonic loss, in part, is related to untimely secretion of PGF2α and premature luteolysis, any management strategy to delay the synthesis and secretion of PGF2α during the time of maternal recognition of pregnancy may reduce the occurrence of early embryonic loss. Consequently, researchers have investigated the potential use of PGF2α inhibitors to address the risk of embryonic loss. Conclusions and Applications Non-steroidal anti-inflammatory drugs (NSAID) are known inhibitors of PGF2α. In cattle, application of NSAID, as a reproductive tool, to improve fertility has been investigated extensively using a variety of NSAID, timing of administration, and breeding techniques. It seems that many NSAID do not consistently improve reproductive efficiency in cattle, and perhaps, treating all cows with an NSAID after calving is unlikely to be economically advantageous. Nevertheless, the research supports the fact that NSAID, in the form of flunixin meglumine or ibuprofen, consistently improved fertility in cattle, when administered at the time of embryo transfer.

Prostaglandins effect on matrix metallopeptidases and collagen in mare endometrial fibroblasts

An increasing number of studies have shown that prostaglandins (PGs) exert multiple regulatory actions in the processes associated to tissue remodeling and fibrosis. Extracellular matrix (ECM) turnover is mediated by matrix metallopeptidases (MMPs). The knowledge about the regulation of their expression in mare endometrium is still limited. Thus, the aim of this study was to investigate whether: (i) profibrotic transforming growth factor (TGF)-β1 modulates PG production in equine endometrium; and (ii) PGE2 and PGF2α modulate MMPs, their tissue inhibitors (TIMPs), and collagen 1 (COL1) expression. In experiment 1, the effect of TGF-β1 (5 ng/mL) on PG secretion and PG synthases mRNA transcription, after 24 and 48 h treatment of mare endometrial fibroblast and epithelial cells was investigated using ELISA and qPCR. In experiment 2, the effects of PGE2 and PGF2α in doses 10-7M and 10-8M on secretion and MMP1, 2, 9, 13, TIMP1, 2, and COL1A1 mRNA transcription in mare endometrial fibroblasts were assessed. Transforming growth factor-β1 treatment decreased secretion of PGF2α by endometrial fibroblasts (P < 0.05) and PGF2α and PGE2 by endometrial epithelial cells (P < 0.05). Prostaglandin E2 increased MMP-2 and MMP-9, and decreased MMP-13 secretion by endometrial fibroblasts (P < 0.05). Additionally, PGF2α treatment increased MMP-2, MMP-13 and COL1, but decreased MMP-1 secretion by endometrial fibroblasts (P < 0.05). Prostaglandins may be involved in the processes associated to pathological endometrial remodeling by their effect on MMP expression. The effect of PGF2α on COL1 secretion from fibroblasts suggests its profibrotic role in pathological endometrial remodeling.

Luteinizing hormone and ovarian steroids affect in vitro prostaglandin production in the equine myometrium and endometrium

Prostaglandins (PGs) play crucial roles in the regulation of the oestrus cycle and establishment of pregnancy in animals. Luteinizing hormone (LH) and ovarian steroids are involved in regulating endometrial PG production in many species. Their effects on PG production and associated pathways in the mare myometrium and endometrium are the subjects of our interest. This study aimed to evaluate the specific effects of LH and ovarian steroids on equine myometrial and endometrial tissues on (i) PGE2 and PGF2α secretion and (ii) transcription of genes encoding specific enzymes responsible for PG synthesis, such as prostaglandin–endoperoxide synthase (PTGS2), PGE2 synthases (PGES), PGF2α synthases (PGFS), and PGI2 synthases (PGIS), using equine myometrial and endometrial explants. Equine myometrial and endometrial tissues were collected at the mid-luteal (n = 6) and follicular (n = 6) phases of the oestrus cycle and were exposed to: (1) vehicle (control), (2) arachidonic acid (AA, 50 ng/mL, positive control), (3) LH (10 ng/mL), (4) progesterone (P4, 10−7M) and (5) 17-β oestradiol (E2, 10−9M) for 24 h. After exposure, PGF2α and PGE2 concentrations were determined using direct enzyme immunoassays. Alterations in PG synthase mRNA expression were determined using RT-qPCR. After 24 h, LH and P4 increased PGE2 and PGF2α secretion by myometrial tissues at the mid-luteal phase (P < 0.05), whereas PG secretion was augmented by LH and E2 during the follicular phase (P < 0.01). In contrast, LH and E2 increased PGE2 and PGF2α secretion by endometrial tissues during the mid-luteal phase (P < 0.05), while E2 enhanced PGE2 secretion during the follicular phase of the oestrus cycle (P < 0.01). These results indicate that LH and ovarian steroids modulate PG production in equine myometrial and endometrial tissues and affect PG synthase expression at the mRNA level. We conclude that the equine myometrium is an alternative source of PG production and participates in the regulation of uterus function during the oestrus cycle.

Prokineticin 1-prokineticin receptor 1 signaling promotes angiogenesis in the porcine endometrium during pregnancy†.

Pregnancy establishment in mammals, including pigs, requires proper communication between embryos and the maternal reproductive tract. Prokineticin 1 (PROK1) has been described as a secretory protein with pleiotropic functions and as a novel tissue-specific angiogenic factor. However, despite the studies performed mainly on human cell lines and in mice, the function of PROK1 in the endometrium during early pregnancy is still not fully elucidated. We hypothesized that PROK1 contributes to pregnancy establishment in pigs. The present study is the first to report that the expression of PROK1 and its receptor (PROKR1) is elevated in the porcine endometrium during the implantation and early placentation period. PROK1 protein was detected mainly in luminal epithelial cells, glandular epithelial cells, and blood vessels in the endometrium. Using the porcine in vivo model of unilateral pregnancy, we revealed that conceptuses induced the endometrial expression of PROK1 and PROKR1. Moreover, the embryonic signal, estradiol-17β, as well as progesterone, stimulated the endometrial expression of PROK1 and PROKR1. We also evidenced that PROK1-PROKR1 signaling supports endometrial angiogenesis in pigs. The PROK1-stimulated proliferation of primary porcine endometrial endothelial (PEE) cells involved PI3K/AKT/mTOR, MAPK, cAMP, and NFKB signaling pathways. Furthermore, PROK1 via PROKR1 promoted the formation of capillary-like structures by PEE cells. PROK1 also stimulated VEGFA and PGF2α secretion, which in turn may indirectly support angiogenic changes within endometrial tissue. In summary, our study suggests that PROK1 acts as an embryonic signal mediator that regulates endometrial angiogenesis and secretory function during the implantation and early placentation period in pigs.

Inhibition of GPR91 Reduces Inflammatory Mediators Involved in Active Labor in Myometrium.

Results GPR91 mRNA expression was significantly higher in myometrium from women during term spontaneous labor compared to no labor. Likewise, in mice, GPR91 mRNA expression was significantly upregulated in myometrium during inflammation-induced preterm labor compared to preterm no labor. In myometrial cells, IL1B and TNF significantly increased GPR91 mRNA expression. Knockdown of GPR91 by siRNA in myometrial cells significantly suppressed the secretion and/or expression of IL1B- and TNF-induced proinflammatory cytokines (GM-CSF, IL1A, IL1B, and IL6) and chemokines (CXCL8 and CCL2), myometrial contractility (expression of the contraction-associated proteins PTGFR and CX43, secretion of the uterotonic PGF2α, and in situ collagen gel contraction), and the transcription factor NF-κB. Conclusion Our findings demonstrate that GPR91 is involved in the genesis of proinflammatory and prolabor mediators induced by IL1B or TNF and collectively suggest that GPR91 may contribute to augmentation of the labor processes.

Pregnancy per artificial insemination during summer in lactating dairy cows after treatment with aspirin

Embryonic loss in cattle may be related to a hormonal imbalance resulting in alterations in timing of prostaglandin F2α (PGF2α) secretion around the time of maternal recognition of pregnancy. The objective of this study was to examine effects of aspirin (a PGF2α inhibitor) on pregnancy per AI (P/AI), and progesterone (P4), and pregnancy specific protein B (PSPB) concentrations in lactating dairy cows inseminated more than once after parturition. Fourteen days after second or subsequent AI (Day 0 = Day of AI), 556 cows were assigned randomly to aspirin (187.2 g total; n = 277) or control (n = 279) groups. Aspirin was administered orally on Day 14 and 15, and control cows were subjected to sham bolus administration. On Day 25, blood samples were collected from a subset of cows (n = 194) to quantify P4 and PSPB, whereas pregnancy was determined in all cows at 35–42 days post-AI. Maximum daily ambient temperature ranged from 38-41 °C during the experiment. Mean parity, days in milk, and times bred before treatment (TBRD) did not differ between groups. There were no differences in P/AI between treatments (aspirin 21.6 % compared with control 27.5 %). Neither treatment, parity, TBRD, or any two-way interactions with treatment affected concentrations of P4. Moreover, there were no effects (P > 0.50) of treatment, or treatment by TBRD interaction on serum PSPB concentrations. A tendency (P = 0.07) occurred for multiparous cows to have greater serum PSPB concentrations compared with primiparous cows. Mean serum PSPB concentrations tended (P = 0.07) to be greater for second or third TBRD compared to fourth and greater TBRD. These results provide evidence that aspirin administered during periods of heat stress after the second and subsequent AI post-partum during the summer months does not improve P/AI or alter P4 and PSPB in lactating dairy cows.

Suppression of COX-2 mRNA abundance in in vitro cultured goat (Capra hircus) endometrial cells by RNA interference and effect on PGF2-α and PGE2 concentrations

Cyclooxygenase-2 (COX-2) has important functions in the synthesis and release of endometrial prostaglandin F2α (PGF2α). Excessive production of COX-2 leads to an increase in endometrial PGF2α synthesis and subsequently causes luteolysis and early embryonic mortality. The aim of this study was to investigate in goats the effects of COX-2 small interference RNA (siRNA) on COX-2 mRNA abundance and the secretion of PGF2α and PGE2 in goat endometrial cells. Endometrial cells isolated from goat uteri were cultured at 38.5 °C and 5% CO2. The cells were treated with different concentrations (0, 10, 25, 50, 100, 250, 500, 750 and 1000 nM per well) of three different COX-2 siRNAs at confluency for 24 h. At 24 h post culture, COX-2 mRNA abundance was quantified using qPCR and PGF2α and PGE2 concentrations were quantified in the culture medium. There was a lesser relative abundance of COX-2 mRNA in endometrial cells at 100 to 1000 nM siRNA. The greatest extent of abundance suppression, however, was observed with 1000 nM siRNA. Transfection of COX-2 siRNA (1000 nM) to endometrial cells suppressed the COX-2 mRNA abundance by 77%, 82%, and 84% with siRNA 1, 2, 3, respectively. Furthermore, with COX-2 siRNA transfected cells, there was a lesser (P < 0.05) PGF2α concentration than in cells not transfected, whereas PGE2 secretion was not affected. The results of the study provide evidence that COX-2 siRNA used in this study suppresses COX-2 mRNA abundance and PGF2α secretion but there was no association between PGE2 concentrations and COX-2 mRNA abundance in goat endometrial epithelial cells.