Mitochondrial DNA content and developmental competence of blastocysts derived from pre-pubertal heifer oocytes

In the cattle-breeding industry, there is an increasing demand for in vitro embryo production from pre-pubertal heifers. In this study, we evaluated the differences in mitochondrial DNA content, oxidative stress, and developmental competence in blastocysts derived from pre-pubertal and pubertal heifers. We found higher mitochondrial DNA copy numbers in blastocysts produced from pre-pubertal heifers than from pubertal heifers. In the group of pre-pubertal animals, there was a significantly lower number of blastocysts produced in vitro from the same number of collected oocytes, and these blastocysts did not differ from those obtained from pubertal oocytes in terms of their morphological quality. The morphologically appropriate blastocysts derived from pre-pubertal heifers had higher concentrations of reactive oxygen species and glutathione. In blastocysts derived from pre-pubertal heifers, we found alterations in the expression of gene markers for developmental competence, which correlated with higher mitochondrial DNA content, suggesting a lower quality of blastocysts derived from pre-pubertal animals than from pubertal animals. The inadequate redox balance in blastocysts obtained from pre-pubertal females, along with higher mitochondrial DNA copy number, as well as differential gene expression of markers of developmental competence, elucidate the low quality of blastocysts derived from pre-pubertal animals, despite their unaltered morphology.

Inflammation-Related Molecules at the Maternal–Fetal Interface during Pregnancy and in Pathologically Altered Endometrium

The blastocyst expresses paternally derived alloantigens and induces inflammation during implantation. However, it is necessary for the onset of pregnancy. An abnormal response might result in a pathological course of pregnancy or pregnancy failure. On the other hand, a state of maternal immune tolerance is necessary to ensure the normal development of pregnancy by suppressing inflammatory processes. This article discusses recognized mechanisms and the significance of inflammatory processes for embryo implantation and pregnancy establishment. We would also like to present disorders involving excessive inflammatory response and their influence on events occurring during embryo implantation. The chain of correlation between the processes responsible for embryo implantation and the subsequent physiological course of pregnancy is complicated. Many of those interrelationships are still yet to be discovered. Undoubtedly, their recognition will give hope to infertile couples for the emergence of new treatments that will increase the chance of giving birth to a healthy child.

Humoral Response after Vaccination with Half-Dose of BNT162b2 in Subjects under 55 Years of Age

In the context of the ongoing COVID-19 pandemic, using a half-dose schedule vaccination can help to return to normalcy in a cost-efficient manner, which is especially important for low and middle-income countries. We undertook a study to confirm that in adults up to 55 years old, the humoral response to the half-dose (15 µg, 35 participants between 18 and 55 years old) and to the recommended dose (30 µg, 155 participants) in the two-dose three-week interval schedule would be comparable. Antibody levels were measured by the Elecsys Anti-SARS-CoV-2 S assay (Roche Diagnostics, upper detection limit: 2570 BAU/mL) on the day of dose 2 of the vaccine and then 8-10 days later to assess peak response to dose 2. The difference in proportions between the participants who did and did not exceed the upper detection limit 8-10 days after dose 2 was not statistically significant (p = 0.152). We suggest that a half-dose schedule can help to achieve widespread vaccination coverage more quickly and cheaply.

Humoral Response to SARS-CoV-2 Vaccine of a Patient Receiving Methotrexate Treatment and Implications for the Need of Monitoring

We report a case of monitoring the antibody response to the BioNTech–Pfizer vaccine of a 50-year-old female diagnosed with rheumatoid arthritis undergoing treatment with methotrexate (MTX). Antibody levels were measured 21 days after dose 1 (i.e., on the day of dose 2) and then 8, 14 and 30 days after dose 2 with Elecsys Anti-SARS-CoV-2 S assay (Roche Diagnostics). Patient showed a negative result after dose 1 and had the serum sample retested using a LIAISON^® SARS-CoV-2 TrimericS IgG assay (DiaSorin), which showed a positive result. Subsequent samples were tested using both assays. Antibody levels kept increasing but at a much slower rate than in patients not receiving any immunomodulatory therapies. Other research indicates that among patients with autoimmune diseases, those receiving disease-modifying antirheumatic drugs (DMARDs) have higher COVID-19 mortality than those treated with tumor necrosis factor inhibitors (TNFis). These results indicate the need for people with autoimmune diseases to be carefully observed following vaccinations, including testing of antibody levels, and treated as potentially at risk until the effect of vaccination is confirmed. The different available vaccines should also be tested to verify their usefulness in the case of people with autoimmune diseases and those who take different immunomodulatory medications.

Hypothyroidism Affects Uterine Function via the Modulation of Prostaglandin Signaling

Thyroid hormones control the functions of almost all body systems. Reproductive dysfunctions, such as abnormal sexual development, infertility, or irregularities in the reproductive cycle, might be associated with thyroid disorders. Uterine receptivity is the period when the uterus is receptive to the implantation of an embryo. During the receptivity period (implantation window), a newly formed blastocyst is incorporated into the uterine epithelium. Prostaglandins are well-known primary mediators of pathological conditions such as inflammation and cancer but are also essential for the physiology of female reproduction. The aim of this study was to evaluate the possible relationship between hypothyroidism and changes in the prostaglandin signaling pathways in the uterus and in the process of uterine receptivity in a rat model. The results show that hypothyroidism impaired uterine receptivity by decreasing the level of E2 as well as decreasing the expression of the uterine-receptivity factors homeobox A10 and osteopontin. Moreover, hypothyroidism caused changes in the expression of elements of the prostaglandin E₂, F_2α, and I₂ signaling pathways and changed the levels of those prostaglandins in the uterine tissue. The results suggest that the mechanisms by which hypothyroidism affects female reproductive abnormalities might involve the prostaglandin signaling pathway, resulting in a subsequent reduction in uterine receptivity.

Expression profile of developmental competence gene markers in comparison with prostaglandin F2α synthesis and action in the early- and late-cleaved pre-implantation bovine embryos

The kinetics of early cleavage stages can affect embryo quality. The bovine model of early- and late-cleaved embryos has been described in the literature and is deemed a useful tool in the field of oocyte developmental competence studies. The expression of genes demonstrating developmental potential differs between early- and late-cleaved embryos. Previously, we demonstrated that prostaglandin F_2α synthase (PGFS) and prostaglandin F_2α receptor (PTGFR) expression depend on the developmental stage and embryo quality. In the present study, we used the same model to determine the mRNA expression profile of developmentally important genes (IGF1R, IGF2R, PLAC8, OCT4, SOX2) in early, expanded and hatched blastocysts obtained from the early- and late-cleaved group of embryos, as well as to correlate the transcription levels of these embryonic gene markers with the transcription levels of PGFS and PTGFR. The mRNA expression of PGFS, PTGFR and factors described as gene markers of embryonic implantation ability and developmental competence genes was determined by real-time PCR. The obtained results were analysed using statistical software GraphPad prism 6.05. During the course of our analyses, we observed that the transcript abundance of most analysed genes tends to be higher in the late-rather than in the early cleaved group of embryos, as well as in B and/or C grade embryos rather than in A grade embryos. On the other hand, for the early cleaved group of blastocysts with cavity, we detected higher PLAC8 mRNA expression for grade A embryos compared with grade C embryos. It suggests that the mRNA expression level of genes depends on the quality of embryos but differs according to various factors including the method of production or culture method. Moreover, numerous correlations between analysed gene markers and PGF_2α synthase and PGF_2α receptor suggest that PGF_2α plays a role in the crucial steps of bovine embryo development.

Iloprost affects in vitro maturation and developmental competence of bovine oocytes

Prostacyclin (PGI2) is synthesised in oviductal fluid and enhance the embryo development during the preimplantation period. The objective of the present study was to determine the effect of an analogue of prostacyclin (iloprost) on the in vitro maturation (IVM) and the developmental competence of bovine oocytes. Cumulus oocyte complexes (COCs) were cultured in maturation medium with iloprost (0.5 μM) for 24 h. We found that iloprost assisted maturation rates and cumulus cell expansion of bovine oocytes, and it increased the mRNA expression of genes related to cumulus expansion: ADAM17, AREG, and TNFAIP6 and cathepsin genes (CTSK and CTSS). Moreover, iloprost reduced the occurrence of apoptosis in COCs and promoted an antiapoptotic balance in the transcription of genes involved in apoptosis (BAX and BCL2). COCs treatment with iloprost during IVM also reduced intracellular reactive oxygen species (ROS) levels, while glutathione (GSH) levels and the mRNA expression of antioxidant genes CAT and GPx4 were markedly increased. We also showed that an analogue of PGI2 influenced the mitochondrial status via distribution rates of mitochondria and mitochondrial membrane potential in oocytes. Although, iloprost-enhanced maturation had no direct effect on number of embryos cleaved, it increased blastocyst rates of bovine embryos as well as proportion of expanded blastocysts. These results indicate that the supplementation of maturation medium with iloprost is beneficial for the maturation efficiency and developmental competence of bovine oocytes.

Prostaglandin E2 affects in vitro maturation of bovine oocytes

The role of prostaglandin E₂ (PGE₂) in the successful resumption of oocyte meiosis and cumulus expansion has been well-documented. However, there remains very little information available on the influence of PGE₂ on other processes that occur during oocyte maturation. In this study, we supplemented a maturation medium with PGE₂ and monitored oocyte quality markers, glucose metabolism, mitochondrial status, oxidative stress, and apoptosis in the cumulus-oocyte complexes (COCs), using a well-established in vitro model of embryo production in cattle. We found that this increased availability of PGE₂ during maturation led to an increase in the expression of genes associated with oocyte competence and improved the quality of blastocysts produced. Prostaglandin E₂ also appeared to stimulate glucose uptake and lactate production in the COCs, both influencing the expression of enzymes involved in glycolysis and the hexosamine biosynthetic pathway. We found that PGE₂ reduced intracellular reactive oxygen species levels, and simultaneously increased glutathione concentration and stimulated antioxidant gene expression in the oocyte. These results indicate that PGE₂ has an important role in the protection of oocytes against oxidative stress. Mitochondrial membrane potential was also improved in PGE₂-treated oocytes, and there was a reduction in the occurrence of apoptosis in the COCs. Promotion of an anti-apoptotic balance in transcription of genes involved in apoptosis was present in both oocytes and the cumulus cells. In summary, PGE₂ could represent a novel autocrine/paracrine player in the mechanisms that can facilitate successful oocyte maturation and oocyte survival in the cow.

Prostaglandin F2α (PGF2α) production possibility and its receptors expression in the early- and late-cleaved preimplantation bovine embryos

BACKGROUND

Prostaglandin F_2α (PGF_2α) is an important component for the physiology of female reproductive processes. In the literature, the data pertaining to the synthesis and action of PGF_2α in early embryonic bovine development are limited. In our study, we used the bovine in vitro culture model based on the time of first cleavage to determine the mRNA expression and immunolocalization of PGF_2α synthase and its receptor in bovine embryos from the 2-cell stage to the hatched blastocyst stage. We also evaluated PGF_2α production at 2, 5 and 7 days of in vitro culture.

RESULTS

We found a significantly higher proportion of blastocysts obtained from the early-cleaved embryos than from the late-cleaved embryos (37.7% vs. 26.1% respectively, P < 0.05). The PGFS mRNA expression was significantly higher in the late-cleaved group than in the early-cleaved group at the 2-, 4- and 16-cell stages (P < 0.05). For PTGFR, we observed that within the late-cleaved group, the mRNA abundance was significantly higher in embryos at the 2- and 16-cell stages than in embryos at the 4- and 8-cell stages (P < 0.05). We observed that PTGFR mRNA expression was significantly higher in the 2- and 16-cell embryos in the late-cleaved group than that in the early-cleaved group embryos (P < 0.05). Among the blastocysts, the PGFS and PTGFR expression levels showed a trend towards higher mRNA expression in the late-cleaved group than in the early-cleaved group. Analysis of PGF_2α production showed that within the early-cleaved group, the content of PGF_2α in the in vitro culture medium was significantly higher on day 7 than it was on day 2 (P < 0.05).

CONCLUSIONS

The mRNA expression levels of PGF_2α synthase and its receptor depend on the developmental stage and the embryo quality. Analyses of PGFS and PTGFR expression in bovine blastocysts and of PGF_2α embryo production suggest that prostaglandin F_2α can act in an autocrine and paracrine manner in bovine in vitro-produced preimplantation embryos. Moreover, the tendency of PTGFR and PGFS mRNA expression to be upregulated in embryos with low developmental potential can indicate a compensation mechanism related to high PGFS and PTGFR mRNA expression levels in low-quality embryos.

Expression of enzymes involved in the synthesis of prostaglandin E2 in early- and late-cleaved bovine embryos at different stages of preimplantation development

Prostaglandin (PG) E₂ plays a role in numerous aspects of mammalian reproduction, such as oviductal transport of gametes, hatching from the zona pellucida in blastocysts and early embryonic development. Despite the evident role of PGE₂ in the regulation of female reproductive processes, in the literature, there is very little information concerning the expression of PGE₂ synthesizing enzymes and the exact amount of PGE₂ produced by bovine embryos in vitro. In the present study, we aimed to determine the mRNA levels and immunolocalization of the enzymes responsible for PGE₂ synthesis (PTGS2, mPGES1, mPGES2 and cPGES) in embryos at the 2-cell, 4-cell, 8-cell, 16-cell, morula, early blastocyst, blastocyst, expanded blastocyst and hatched blastocyst stages, using a well-defined bovine model of oocyte developmental competence based on the time of first cleavage. PTGS2, mPGES2 and cPGES transcripts and proteins were detected in all stages of embryos, whereas the mPGES1 transcript and protein were not detected in embryos from the 2- to 16-cell stage. The results showed different transcription profiles of the enzymes involved in PGE₂ synthesis in early- and late-cleaved embryos during the early stages of their in vitro preimplantation development. We also found that all the analysed stages of bovine preimplantation embryos released PGE₂, with the highest concentration on Day 7 of culture in both the early- and late-cleaved groups. The present study is the first to demonstrate PGE₂ synthesis and production by bovine early- and late-cleaved embryos at different stages of preimplantation development. Bovine embryos can produce PGE₂, which may exert paracrine regulation during development. The transcription levels of PGE₂ synthases were affected by the embryonic stage of development and quality. Our results indicate that the different transcription profiles of PTGS2, mPGES1, mPGES2 and cPGES, as well as PGE₂ concentration, in early-versus late-cleaved embryos are dependent on the quality of the oocytes from which the embryos were obtained, which could reveal the association of PGE₂ production during bovine preimplantation development with more advanced stages of embryo development.

Altered expression of lysophosphatidic acid receptors, in association with the synthesis of estrogens and androgens in type 1 endometrial cancer biology

To establish association between two main lysophosphatidic acid (LPA) receptors (LPAR2 and LPAR1) with the synthesis of estrogens and androgens in type-1 endometrial carcinoma (EC), we evaluated correlation of LPARs expression with expression of steroid 5 alpha-reductase 2 - aromatase (SRD5A2), or cytochrome P450 family 19 subfamily A member 1-5α-reductase (CYP19A1) in EC. Moreover, we aimed to investigate SRD5A2 and CYP19A1 expression in type 1 endometrial cancer and normal endometrium with its correlation to selected clinicopathological features. The studied cancerous samples showed higher CYP19A1 and SRD5A2 expression comparing to normal endometria. We also documented positive correlations between LPAR1 and LPAR2 with responsible for proliferation SRD5A2 in EC tissue which suggests that intratumoral estrogen metabolism and synthesis are pivotal in endometrial carcinoma progression, with the involvement of LPA in this process. However, positive correlation between CYP19A1 and LPAR1 accounts for supporting role of LPA acting via LPAR1 in intratumoral DHT concentration and the ethiology of endometrial cancer progression. Also, owing to the highest expression of LPARs, CYP19A1 and SRD5A2 as well as their association with depth of myoinvasion and FIGO stage LPAR2 and LPAR1 seem to be the efficient candidate prognostic markers in the individual, targeted therapies for EC.

LPAR2 and LPAR4 are the Main Receptors Responsible for LPA Actions in Ovarian Endometriotic Cysts

Endometriosis has been considered as an estrogen (E2)-dependent and progesterone (P4)-resistant disease. On the other hand, lysophosphatidic acid (LPA) has been suggested as a significant modulator of ovarian pathology, acting via both LPA levels and LPA receptor (LPAR) upregulation. Therefore, the objective of the present study was to evaluate LPA concentration as well as LPARs, autotaxin (ATX), and phospholipase A2 (PLA2) expression in ovarian endometriotic cysts and normal endometrium with correlation of the expression of E2 and P4 receptors in endometriotic cysts. The analyses were carried out using the tissues derived from 37 patients with ovarian endometriosis and 20 endometrial samples collected from women without endometriosis were used as a control. We found that ovarian endometriotic cysts are a site of LPA synthesis due to the presence of enzymes involved in LPA synthesis in the tissue. Additionally, when we compared endometriotic cysts versus normal endometrium, we were able to show overexpression of 3 from 6 examined LPARs and both enzymes responsible for LPA synthesis in endometriotic cysts. Finally, we found the correlations between LPARs, ATX, and PLA2 and the expression of E2 and P4 receptors in endometriotic cysts. Owing to the high LPAR2 and LPAR4 transcript and protein expression in endometriotic ovarian cysts and positive correlations of both these receptors with the PR-B and ERβ, respectively, those receptors seem to be the most promising predictors of the endometriotic cysts as well as the main receptors responsible for LPA action in the ovarian endometriosis.

Expression of factors involved in apoptosis and cell survival is correlated with enzymes synthesizing lysophosphatidic acid and its receptors in granulosa cells originating from different types of bovine ovarian follicles

BACKGROUND

Lysophosphatidic acid (LPA) regulates reproductive processes in the cow. Ovarian granulosa cells play a pivotal role in follicle growth and development. Nevertheless, the role of LPA in the local regulation of granulosa cell function in different follicle categories in the bovine ovary has not been investigated.

METHODS

Ovarian follicles were divided into healthy, transitional and atretic categories. The expression levels of AX, PLA2, LPARs and factors involved in apoptosis and cell survival processes in granulosa cells in different types of follicles were measured by real-time PCR. The correlations between the expression levels of AX, PLA2, LPARs and the examined factors were measured. The immunolocalization of AX, PLA2 and LPARs in different ovarian follicles was examined by immunohistochemistry. Statistical analyses were conducted in GraphPad using a one-way ANOVA followed by the Kruskal-Wallis multiple comparison test or a correlation analysis followed by Pearson's test.

RESULTS

The expression levels of AX, PLA2 and LPARs, with the major role of LPAR2 and PLA2, were found in the granulosa cells originating from different follicle types. The expression levels of the factors involved in cell apoptosis (TNFα and its receptors, FAS, FASL, CASP3, CASP8, β-glycan, and DRAK2) were significantly higher in the granulosa cells of the atretic follicles compared to the healthy follicles. A number of correlations between LPARs, AX, PLA2 and factors associated with apoptosis were observed in the atretic but not in the healthy follicles. A greater expression of the factors involved in differentiation and proliferation in the granulosa cells (DICE1 and SOX2) was found in the healthy follicles in comparison with the atretic. A number of correlations between LPARs, AX, PLA2 and the factors associated with cell survival were observed in the healthy but not in the atretic follicles.

CONCLUSIONS

Granulosa cells are the target of LPA action and the source of LPA synthesis in the bovine ovarian follicle. We suggest that the participation of LPA in apoptosis in the atretic follicles mainly occurs through the regulation of TNF-α-dependent and caspase-induced pathways. In the transitional follicles, LPA might influence the inhibins to shift the balance between the number of healthy and atretic follicles. In the healthy follicle type, LPA, acting via LPAR1, might regulate MCL1 and estradiol-stimulating ERβ mRNA expression, leading to the stimulation of anti-apoptotic processes in the granulosa cells and their differentiation and proliferation.

The effect of lysophosphatidic acid together with interferon tau on the global transcriptomic profile in bovine endometrial cells

In cows, lysophosphatidic acid (LPA), which acts in an auto/paracrine manner, serves as a luteotropic factor during early pregnancy by stimulating progesterone and prostaglandin E₂ secretion, thus protecting the bovine corpus luteum and early embryo development. Our hypothesis was that LPA exerted some local effects on the bovine endometrium prior to early embryo-maternal interactions and that interferon tau (IFNτ), the pregnancy recognition signal, modulated this action. In the present study, we applied an in vitro model involving whole-transcriptomic profiling to examine the effects of LPA on gene expression in bovine endometrial cells. Microarray analyses revealed 36, 269 and 284 differentially expressed transcripts in bovine endometrial cells in the control vs. LPA, control vs. LPA + IFNτ and LPA vs. LPA + IFNτ groups, respectively. The expression of matrix metalloproteinase 13 (MMP13) and radical S-adenosyl methionine domain containing 2 (RSAD2) was increased in the LPA-treated endometrial cells. Among the transcripts differentially regulated by LPA together with IFNτ, many of the genes were classical- or novel-type I IFN-stimulated genes (ISGs). The results indicated that 10 of the 16 analyzed genes showed a positive correlation with their corresponding microarray data upon real-time PCR validation, indicating a considerable consistency between both techniques. In summary, these transcriptional profiling studies identified a number of genes that were regulated by LPA alone and LPA together with IFNτ in endometrial cells from the bovine uterus. Available studies support the idea that LPA, which acts in an auto/paracrine manner on the endometrium, alters the expression of genes that are probably important for uterine receptivity, maternal immune tolerance to the embryo and conceptus growth and development during early pregnancy. Moreover, the differentially expressed genes (DEGs) that increased in the LPA + IFNτ-treated endometrial cells are largely in response to IFNτ actions and are possibly associated with crucial biological processes during the peri-implantation period of pregnancy.

Lysophosphatidic Acid Synthesis and its Receptors' Expression in the Bovine Oviduct During the Oestrous Cycle

Lysophosphatidic acid (LPA) is a naturally occurring simple phospholipid which in the bovine reproductive system can be produced in the endometrium, corpus luteum, ovarian follicle and embryo. In this study, we examined the possibility that LPA receptors are expressed, and LPA synthesized, in the bovine oviduct. We found that the concentration of LPA was highest in infundibulum in the follicular phase of the oestrous cycle and was relatively high during the early-luteal phase in all examined parts of the oviduct. We also documented that LPA synthesis engages both available pathways for LPA production. The autotaxin (ATX) protein expression was significantly higher in the infundibulum compared to the isthmus during the follicular phase of the oestrous cycle. During the early-luteal phase of the oestrous cycle, ATX and phospholipase A2 (PLA2) protein expression was highest in ampulla, although the expression of LPARs was not as dynamic as LPA concentration in the oviduct tissue, and we presume that in the bovine oviduct, the most abundantly expressed receptor is LPAR2. In conclusion, our results indicate that the bovine oviduct is a site of LPA synthesis and a target for LPA action in the bovine reproductive tract. We documented that LPAR2 is the most abundantly expressed in the bovine oviduct. We hypothesize that in the bovine oviduct, LPA may be involved in the transport of gametes, fertilization and cellular signalling between the oviduct and cumulus-oocyte complex.

Local effect of lysophosphatidic acid on prostaglandin production in the bovine oviduct

The mammalian oviduct plays an important role in the fertilisation and transport of gametes and embryo. Prostaglandins (PGs) are local mediators of oviductal functions and are involved in fertilisation and the transport of gametes and embryo. Lysophosphatidic acid (LPA), a kind of phospholipid, is involved in various physiological actions. We hypothesised that LPA regulates PG production in the bovine oviduct. To test this hypothesis, we examined the mRNA expression of LPA receptors (LPAR1-6) and LPA-producing enzymes (ATX, PLA1α, PLA1β) in ampullary and isthmic tissues and in cultured epithelial and stromal cells isolated from the bovine oviduct. We also investigated the effects of LPA on PG synthase expression and PG production in cultured cells. The mRNA of LPAR1-4, 6, ATX and PLA1α were expressed in cultured epithelial and stromal cells. The expressions of LPAR1-3 were significantly lower and the expression of LPAR4 was significantly higher in the isthmic than in the ampullary tissues. Lysophosphatidic acid significantly stimulated PG production in the cultured isthmic stromal cells. The overall findings suggest that LPA stimulates PG production via LPAR4 in the bovine oviduct. Since PGs are important for fertilisation and the transport of gametes and embryo, these findings show that locally produced LPA regulates oviductal functions.

Studies on lysophosphatidic acid action during in vitro preimplantation embryo development

Assisted reproductive technologies, including in vitro embryo production (IVP), have been successfully used in animal reproduction to optimize breeding strategies for improved production and health in animal husbandry. Despite the progress in IVP techniques over the years, further improvements in in vitro embryo culture systems are required for the enhancement of oocyte and embryo developmental competence. One of the most important issues associated with IVP procedures is the optimization of the in vitro culture of oocytes and embryos. Studies in different species of animals and in humans have identified important roles for receptor-mediated lysophosphatidic acid (LPA) signaling in multiple aspects of human and animal reproductive tract function. The data on LPA signaling in the ovary and uterus suggest that LPA can directly contribute to embryo-maternal interactions via its influence on early embryo development beginning from the influence of the ovarian environment on the oocyte to the influence of the uterine environment on the preimplantation embryo. This review discusses the current status of LPA as a potential supplement in oocyte maturation, fertilization, and embryo culture media and current views on the potential involvement of the LPA signaling pathway in early embryo development.

Endothelin as a local regulating factor in the bovine oviduct

Endothelin (EDN) is a possible regulating factor of oviductal motility, which is important for the transport of gametes and embryo. To clarify the factors that control the secretion of EDN in the bovine oviduct, the expression of EDNs, EDN-converting enzymes (ECEs) and EDN receptors (EDNRs) were investigated. All isoforms of EDN (EDN1–3), ECE (ECE1 and ECE2) and EDNR (EDNRA and EDNRB) were immunolocalised in the epithelial cells of the ampulla and the isthmus. EDNRs were also immunolocalised in smooth-muscle cells. The mRNA expression of EDN2 and ECE2 was higher in cultured ampullary oviductal epithelial cells than in isthmic cells. The expression of EDN1, EDN2 and ECE2 in the ampullary tissue was highest on the day of ovulation. Oestradiol-17β increased EDN2 and ECE1 expression, while progesterone increased only ECE1 expression in cultured ampullary epithelial cells. These results indicate that EDNs are produced by epithelial cells and their target site is smooth-muscle and epithelial cells, and suggest that ovarian steroids are regulators of endothelin synthesis in ampullary oviductal epithelial cells.

Lysophosphatidic acid modulates prostaglandin signalling in bovine steroidogenic luteal cells

We examined whether lysophosphatidic acid affects prostaglandin biosynthesis, transport, and signalling in bovine steroidogenic luteal cells. The aim of the present study was to determine the influence of LPA on PGE2 and PGF2α synthesis and on the expression of enzymes involved in PG biosynthesis (PTGS2, mPGES-1, cPGES, mPGES-2, PGFS and 9-KPR), prostaglandin transporter (PGT), and prostaglandin receptors (EP1, EP2, EP3, EP4 and FP) in bovine steroidogenic luteal cells. We found that LPA inhibited PGF2α synthesis in steroidogenic luteal cells. Moreover, LPA increased mPGES1 and cPGES and decreased PGFS expression in cultured bovine steroidogenic luteal cells. Additionally, LPA stimulated EP2 and EP4 receptor and PGT expression. This study suggests that LPA activity in the bovine CL directs the physiological intraluteal balance between the two main prostanoids towards luteotropic PGE2.

First Pregnancy, Somatic and Psychological Status of a 4-Year-Old Child Born following Annexin V TESA Sperm Separation

Introduction Sperm DNA integrity is a crucial paternal factor affecting fertilization and pregnancy rates, as well as embryo development. Case The present case report describes the successful pregnancy after testicular sperm aspiration (TESA) combined with intracytoplasmic sperm injection (ICSI) (TESA-ICSI) in a couple where the male presented high sperm DNA fragmentation. In order to sort damaged sperm presenting DNA fragmentation, magnetic activated cell sorting (MACS) with annexin V microbeads (MACS Miltenyi Biotec, Teterow, Germany) was used. Conclusion The authors present the first description of a successful medical case using TESA-ICSI annexin V sperm sorting. Additionally, a follow-up of the child at the age of 4 years old was done.

Healthy Baby Born to a Robertsonian Translocation Carrier following Next-Generation Sequencing-Based Preimplantation Genetic Diagnosis: A Case Report

Preimplantation genetic diagnosis (PGD) is well established method for treatment of genetic problems associated with infertility. Moreover, PGD with next-generation sequencing (NGS) provide new possibilities for diagnosis and new parameters for evaluation in, for example, aneuploidy screening. The aim of the study was to report the successful pregnancy outcome following PGD with NGS as the method for 24 chromosome aneuploidy screening in the case of Robertsonian translocation. Day 3 embryos screening for chromosomal aneuploidy was performed in two consecutive in vitro fertilization (IVF) cycles, first with fluorescent in situ hybridization (FISH), and then with NGS-based protocol. In each IVF attempt, three embryos were biopsied. Short duration of procedures enabled fresh embryo transfer without the need for vitrification. First IVF cycle with the embryo selected using PGD analysis with the FISH method ended with pregnancy loss in week 8. The second attempt with NGS-based aneuploidy screening led to exclusion of the following two embryos: one embryo with 22 monosomy and one with multiple aneuploidies. The transfer of the only euploid blastocyst resulted in the successful pregnancy outcome. The identification of the euploid embryo based on the NGS application was the first successful clinical application of NGS-based PGD in the case of the Robertsonian translocation carrier couple.

The significance of the altered expression of lysophosphatidic acid receptors, autotaxin and phospholipase A2 as the potential biomarkers in type 1 endometrial cancer biology

In order to study lysophosphatidic acid (LPA) signaling associated with type 1 endometrial carcinoma (EC), we evaluated the LPA receptors (LPARs), autotaxin (ATX) and phospholipase A2 (PLA2) expression in EC and normal endometrium with correlation to clinicopathological features. We investigated LPAR1, LPAR2, LPAR3, LPAR4, ATX and PLA2 expression at mRNA and protein levels using quantitative real-time PCR and western blot analyses in 37 ECs and 10 normal endometria. All the examined LPARs (except for LPAR3 protein), ATX and PLA2 were overexpressed in cancerous compared to healthy endometrium. The studied ECs showed the highest LPAR2 and LPAR1 expression. Statistically positive correlations were found between depth of myoinvasion and levels of LPAR1, LPAR2 and PLA2 transcripts and proteins. We also found positive correlations between LPAR1, LPAR2, LPAR4 and PLA2 expression with the International Federation of Gynecology and Obstetrics (FIGO) stage. The expression of LPAR1, LPAR2 and PLA2 was positively associated with the age of patients. Positive correlations were found between the expression of LPAR1 mRNA, LPAR2 mRNA and protein and LPAR3 mRNA and body mass index (BMI) of the examined patients. We found no association between the expression levels of the studied factors and diabetes or hypertension among the examined patients. Owing to the highest LPAR2 and LPAR1 expression in EC and positive correlations of these two receptors with the depth of myoinvasion and the FIGO stage, we believe that LPAR2 and LPAR1 show promise as predictors of the EC progression as well as the main receptors responsible for LPA action in the EC tissue.

The effect of lysophosphatidic acid during in vitro maturation of bovine cumulus-oocyte complexes: cumulus expansion, glucose metabolism and expression of genes involved in the ovulatory cascade, oocyte and blastocyst competence

BACKGROUND

In the cow, lysophosphatidic acid (LPA) acts as an auto-/paracrine factor, through its receptors LPAR1-4, on oocytes and cumulus cells during in vitro maturation (IVM). The aim of the present work was to determine the effect of LPA during IVM of bovine oocytes on: 1) oocyte maturation; 2) apoptosis of COCs; 3) expression of genes involved in developmental competence and apoptosis in bovine oocytes and subsequent blastocysts; 4) cumulus expansion and expression of genes involved in the ovulatory cascade in cumulus cells; 5) glucose metabolism and expression of genes involved in glucose utilization in cumulus cells; 6) cleavage and blastocyst rates on Day 2 and Day 7 of in vitro culture, respectively.

METHODS

Cumulus-oocyte complexes (COCs) were matured in vitro in the presence or absence of LPA (10(-5) M) for 24 h. Following maturation, we determined: oocyte maturation stage, cumulus expansion, COCs apoptosis and glucose and lactate levels in the maturation medium. Moreover, COCs were either used for gene expression analysis or fertilized in vitro. The embryos were cultured until Day 7 to assess cleavage and blastocyst rates. Oocytes, cumulus cells and blastocysts were used for gene expression analysis.

RESULTS

Supplementation of the maturation medium with LPA enhanced oocyte maturation rates and stimulated the expression of developmental competence-related factors (OCT4, SOX2, IGF2R) in oocytes and subsequent blastocysts. Moreover, LPA reduced the occurrence of apoptosis in COCs and promoted an antiapoptotic balance in the transcription of genes involved in apoptosis (BAX and BCL2) either in oocytes or blastocysts. LPA increased glucose uptake by COCs via augmentation of GLUT1 expression in cumulus cells as well as stimulating lactate production via the enhancement of PFKP expression in cumulus cells. LPA did not affect cumulus expansion as visually assessed, however, it stimulated upstream genes of cumulus expansion cascade, AREG and EREG.

CONCLUSIONS

Supplementation of the maturation medium with LPA improves oocyte maturation rates, decreases extent of apoptosis in COCs and sustains the expression of developmental competence related factors during oocyte maturation and subsequently affects gene expression profile at the blastocyst stage. We also demonstrate that LPA directs glucose metabolism toward the glycolytic pathway during IVM.

105 EFFECT OF LYSOPHOSPHATIDIC ACID ON PROSTAGLANDIN PRODUCTION IN THE BOVINE OVIDUCT

The oviduct is an essential organ for successful pregnancy in mammals. The transport of gametes and early embryos is mainly induced by contraction and relaxation of smooth muscle. The contraction and relaxation of bovine oviductal smooth muscle are induced by prostaglandin (PG) F2α and PGE2, respectively. Lysophosphatidic acid (LPA), a type of phospholipid, is involved in various physiological actions such as promoting inflammation and cellular proliferation in various organs. LPA acts through at least 6 G protein-coupled receptors. Both LPA and LPA receptors are expressed in endometrium and, moreover, LPA affects PG production by the endometrium in cow. Based on the above findings, we hypothesised that LPA is locally involved in PG production by oviductal cells to promote motility of oviductal smooth muscle in cow. Oviductal samples ipsilateral to a corpus luteum or a dominant follicle at peri-ovulation (0–6 and 19–21 days after ovulation) were collected in abattoir. Messenger RNA expression of LPA receptors (LPAR1–6) and LPA-producing enzymes (ATX, PLA1α, PLA1β) was examined in ampullary and isthmic tissues. Expression in cultured epithelial and stromal cells isolated from the bovine oviduct were also examined to determine the cells possessing LPA receptors and LPA-producing enzymes. In addition, the effect of LPA (0.1, 1, 10 μM) on the expression of cyclooxygenase (COX)-1 and COX-2 (PG-synthesising enzymes) and on PGE2 and PGF2α production by cultured epithelial and stromal cells was investigated. The significant differences (P < 0.05) were determined by Student's t-test for 2 groups, and by one-way ANOVA followed by Tukey's multiple comparison test for more than 3 groups. LPAR1–6, ATX, PLA1α, and PLA1β were expressed in both ampullary and isthmic tissues as well as in both cultured epithelial and stromal cells. The expression of LPAR1–3 was significantly lower in the isthmic tissues than in the ampullary tissues, whereas the expression of LPAR4–6 was significantly higher in the isthmic tissues than in the ampullary tissues. The expression of COX-2 was significantly stimulated by 10 μM LPA in cultured isthmic stromal cells. In addition, LPA significantly stimulated both PGE2 and PGF2α production by cultured isthmic stromal cells. In the isthmus of the oviduct, LPA produced by epithelial and stromal cells may stimulate the expression of COX-2 in the stromal cells, followed by increased PG production. Because the mRNA expression of LPAR4–6 is higher in the isthmus than in the ampulla, those effects of LPA might be mediated by activation of LPAR4–6. The overall findings suggest that LPA is one of the regulating factors for transport of gametes and early embryos by controlling the motility of smooth muscle in the bovine oviduct.

Anti-Müllerian hormone (AMH) is a strong predictor of live birth in women undergoing assisted reproductive technology

In the present study, we evaluated the clinical value of the following parameters: basal anti-Müllerian hormone (AMH), follicle-stimulating hormone (FSH), inhibin B and antral follicle count (AFC) in predicting live birth outcomes. The study involved 603 women undergoing in vitro fertilization (IVF) using the long protocol for controlled ovarian hyperstimulation (COH). Serum levels of AMH, FSH and inhibin B as well as AFC were measured on the first three days of the menstrual cycle prior to the beginning of stimulation. AMH was the only independent parameter that correlated with the chance of live birth. We found that live birth rates of 46.2% (patient age <35 years), 44.7% (35-37 years), 32.1% (38-39) and 15.3% (>39) were associated with concentrations of AMH>1.4 ng/ml. For the AMH range 0.6-1.4 ng/ml, the live birth rates were 29.3%, 12.5%, 5.6% and 2.7%, respectively, and for AMH concentrations below 0.6 ng/ml the rates were 7.1%, 8.3%, 0% and 5.8%, respectively. Independently of other parameters affecting the chance of live birth, the success rate was the highest when the AMH level was >2 ng/ml, significantly lower when the AMH concentration was about 1 ng/ml, and 0% when the AMH concentration was ∼0.1 ng/ml. In conclusion, this is the first report to demonstrate that AMH level correlated better than age, FSH or inhibin B concentrations or AFC with live birth outcome. Therefore, the basal serum concentration of AMH may become a new, substantial prognostic factor regarding live birth above and beyond other currently available predictors of IVF outcome.

Effects of lysophopatidic acid on tumor necrosis factor α and interferon γ action in the bovine corpus luteum

We examined the effects of LPA on TNFα and IFNγ - induced decrease of P4 synthesis and on the cytokine - induced apoptosis of the cultured luteal cells. In the steroidogenic luteal cells LPA reversed the inhibitory effect of TNFα and IFNγ on P4 synthesis and also inhibited the stimulatory effects of TNFα and IFNγ on the expression of Bax, TNFR1, Fas and FasL as well as caspase 3 activity. These results suggest that TNFα and IFNγ cannot induce apoptosis in the presence of LPA, which orientates the steroidogenic luteal cells towards the survival state. In conclusion our results indicate that LPA supports P4 synthesis and action in the bovine CL.

Lipopolysaccharides, cytokines, and nitric oxide affect secretion of prostaglandins and leukotrienes by bovine mammary gland epithelial cells

The aims of this study were to determine the effects of lipopolysaccharides (LPS), tumor necrosis factor (TNF), interleukin 1 alpha (IL-1α), nitric oxide donor (NONOate), or the combination of TNF + IL-1α + NONOate on the following: (i) secretion of prostaglandin (PG)-F(2α), PGE(2), leukotriene (LT)-B(4), and LTC(4) by epithelial cells of the teat cavity and lactiferous sinus of bovine mammary gland; (ii) messenger RNA (mRNA) transcription of enzymes responsible for arachidonic acid (AA) metabolism (prostaglandin-endoperoxide synthase 2 [PTGS2], prostaglandin E synthase [PTGES], prostaglandin F synthase [PGFS], and arachidonate 5-lipooxygenase [ALOX5]); and (iii) proliferation of the cells. The cells were stimulated for 24 h. Prostaglandins and LT were measured by enzyme immunoassay, mRNA transcription of enzymes was determined by real-time reverse transcription polymerase chain reaction, and the cell viability was measured by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide. All factors increased PG secretion, but the highest stimulation was observed after TNF and IL-1α (P < 0.001). Tumor necrosis factor, NONOate, and TNF + IL-1α + NONOate increased LTB(4) production (P < 0.01), whereas LTC(4) was increased by LPS, TNF, and IL-1α (P < 0.01). Lipopolysaccharides, TNF, IL-1α, and the reagents combination increased PTGS2, PTGES, and PGFS mRNA transcription (P < 0.01), whereas ALOX5 mRNA transcription was increased only by TNF (P < 0.001). Lipopolysaccharides, TNF, IL-1α, NONOate, and the combination of reagents increased the cell number (P < 0.001). Mediators of acute-clinical Escherichia coli mastitis locally modulate PG and LT secretion by the epithelial cells of the teat cavity and lactiferous sinus, which might be a useful first line of defense for the bovine mammary gland. Moreover, the modulation of PG and LT secretion and the changing ratio of luteotropic (PGE(2), LTB(4)) to luteolytic (PGF(2α), LTC(4)) metabolites may contribute to disorders in reproductive functions.

Experimentally induced mastitis and metritis modulate soy bean derived isoflavone biotransformation in diary cows

The present study compared the changes in isoflavone (daidzein and genistein) and their metabolite (equol and para-ethyl-phenol) concentrations in the blood plasma of cows with induced mastitis and metritis after feeding with soy bean. Sixteen cows were divided into four groups: control for mastitis group, cows with induced mastitis group, control for metritis group, and cows with induced metritis group. All cows were fed a single dose of 2.5 kg of soy bean and then blood samples were taken from the jugular vein for 8 h at predetermined intervals. The concentrations of soy bean-derived isoflavones and their active metabolites were measured in the blood plasma on HPLC system. β-Glucuronidase activity in the blood plasma of cows was measured by fluorometric method. In the blood plasma of cows with induced mastitis and metritis, we found considerably higher concentrations and time-dependent increase in isoflavone metabolites (equol and para-ethyl-phenol) with reference to cyclic cows (P < 0.05). Moreover, we noticed significant decrease of genistein in the blood plasma of the cows with induced metritis compared with control cows (P < 0.05). In addition, in the blood plasma of the cows with induced metritis, we found an increase in β-glucuronidase activity compared with control cows (P < 0.05). In conclusion, health status of the females influenced the concentrations of isoflavone metabolites in the blood plasma of the cows. Experimentally induced mastitis and metritis increased isoflavone absorption, biotransformation and metabolism. Therefore, we suggest that cows with induced mastitis and metritis are more exposed to active isoflavone metabolite actions than healthy cows.

Ovarian steroids modulate tumor necrosis factor-α and nitric oxide-regulated prostaglandin secretion by cultured bovine oviductal epithelial cells

Ovarian steroids assure an optimum environment for the final maturation of oocytes, gamete transport, fertilization, and early embryonic development. The aim of experiment 1 was to examine the influence of ovarian steroids on tumor necrosis factor-α (TNF-α)- or nitric oxide (NO)-regulated prostaglandin (PG), and nitrite/nitrate (NO₂/NO₃) secretion by cultured bovine oviductal epithelial cells (BOECs). BOECs were pretreated with 17β-estradiol (E₂; 10⁻⁹ M) and/or progesterone (P₄; 10⁻⁷ M) for 24 h. For the next 24 h, BOECs were treated with TNF-α (10 ng/mL) or spermine nitric oxide complex (NONOate; 10⁻⁵ M). Prostaglandin F(2α) and PGE₂ secretion was measured in medium by ELISA. The pretreatment of cells with P₄ (progesterone), E₂ (17 β-estradiol), or E₂/P₄ augmented TNF-α-induced PGF(2α) and PGE₂ secretion (P < 0.01). The pretreatment of cells with E₂ or E₂/P₄ increased NONOate-induced PGF(2α) and PGE₂ secretion (P < 0.01). TNF-α induced NO₂/NO₃ production by BOECs. The pretreatment of cells with E₂ augmented only TNF-α-induced NO₂/NO₃ production (P < 0.05). The aim of experiment 2 was to examine the influence of TNF-α, NO, and ovarian steroids on the protein content of enzymes specifically involved in PG and NO production, PG synthases, and NO synthases (NOSs). BOECs were treated with TNF-α (10 ng/mL) or NONOate (10⁻⁵ M). TNF-α increased the protein content of PGG/H synthase, PGF synthase, and PGE synthase (P < 0.05) and endothelial and inducible NOSs (P < 0.05). Nitric oxide increased the protein content of PGF synthase, PGE synthase, endothelial NOS, and inducible NOS (P < 0.05). These results show possible linkage between TNF-α and NO, modulated by ovarian steroids, in the regulation of PG synthesis by BOECs that may be important for triggering the process of oviductal contractions.

Nitric oxide stimulates progesterone and prostaglandin E2 secretion as well as angiogenic activity in the equine corpus luteum

Cytokines and nitric oxide (NO) are potential mediators of luteal development and maintenance, angiogenesis, and blood flow. The aim of this study was to evaluate (i) the localization and protein expression of endothelial and inducible nitric oxide synthases (eNOS and iNOS) in equine corpora lutea (CL) throughout the luteal phase and (ii) the effect of a nitric oxide donor (spermine NONOate, NONOate) on the production of progesterone (P4) and prostaglandin (PG) E(2) and factor(s) that stimulate endothelial cell proliferation using equine luteal explants. Luteal tissue was classified as corpora hemorrhagica (CH; n = 5), midluteal phase CL (mid-CL; n = 5) or late luteal phase CL (late CL; n = 5). Both eNOS and iNOS were localized in large luteal cells and endothelial cells throughout the luteal phase. The expression of eNOS was the lowest in mid-CL (P < 0.05) and the highest in late CL (P < 0.05). However, no change was found for iNOS expression. Luteal explants were cultured with no hormone added or with NONOate (10(-5) M), tumor necrosis factor-α (TNFα; 10 ng/mL; positive control), or equine LH (100 ng/mL; positive control). Conditioned media by luteal tissues were assayed for P4 and PGE(2) and for their ability to stimulate proliferation of bovine aortic endothelial cells (BAEC). All treatments stimulated release of P4 in CH, but not in mid-CL. TNFα and NONOate treatments also increased PGE(2) levels and BAEC proliferation in CH (P < 0.05). However, in mid-CL, no changes were observed, regardless of the treatments used. These data suggest that NO and TNFα stimulate equine CH secretory functions and the production of angiogenic factor(s). Furthermore, in mares, NO may play a role in CL growth during early luteal development, when vascular development is more intense.

Is interleukin-1α a luteotrophic or luteolytic agent in cattle?

Cytokines are thought to regulate prostaglandin (PG) secretion in the bovine endometrium. However, there is no consensus about the role of interleukin-1α (IL1A) on PG secretion. The objective of this study was to examine the influence of IL1A on basal and interferon-τ (IFNT)-regulated PGin vitrosecretion, as well its effects on PG secretion, progesterone (P4) output, and corpus luteum (CL)in vivolifespan. Explants of bovine endometrium (days 16–17 of the estrous cycle or early pregnancy) were stimulated with IL1A (10 ng/ml), IFNT (30 ng/ml), or IL1A combined with IFN. IL1A alone strongly stimulated luteotrophic PGE2secretion by endometrial tissues of both pregnant and nonpregnant cows. IL1A also stimulated luteolytic PGF2αoutput in the late luteal phase. IFNT augmented the stimulatory effect of IL1A on PGE2secretion. In anin vivoexperiment, saline or IL1A at different doses (0.001–10 μg/per animal) was applied to the uterine lumen on day 16 of the cycle. Only the highest dose of IL1A caused a temporal increase in PGF2αsecretion, while it had no effect on P4secretion or CL lifespan. Application of 0.1 and 1 μg IL1A stimulated P4and PGE2output and prolonged the CL lifespan. Although IL1A may stimulatein vitroluteolytic PGF2αsecretion during the estrous cycle, it only acts as a luteotrophic factorin vivo. IL1A increased luteotrophic PGE2and P4output, inhibiting spontaneous luteolysis. These luteotrophic effects may result in appropriate luteal development and function in cows during the estrous cycle and early pregnancy.

Effects of tumor necrosis factor-alpha and nitric oxide on prostaglandins secretion by the bovine oviduct differ in the isthmus and ampulla and depend on the phase of the estrous cycle

To determine the possible roles of tumor necrosis factor-alpha (TNFalpha) and nitric oxide (NO) in the bovine oviduct, ampulla and isthmus collected during the estrous cycle were exposed for 18 h to TNFalpha, NO donor (NONOate), NO synthase inhibitors (L-NOARG, L-NAME and AMT) and oxytocin (OT) as a positive control. Prostaglandins (PGs) and NO(2)/NO(3) in conditioned media were measured. TNFalpha stimulated PGF(2alpha) secretion on Day 0 (onset of estrus = Day 0) and Days 2-3, in both the ampulla and isthmus, but on Days 18-20 only in ampulla. TNFalpha increased PGE(2) secretion in both fragments in each phase. NONOate did not affect PGF(2alpha) secretion on Days 18-20, whereas this NO donor stimulated PGF(2alpha) secretion in both fragments on Day 0 and Days 2-3. TNFalpha increased NO(2)/NO(3) production in every examined phase in the ampulla and on Days 2-3 in the isthmus. L-NAME lowered NO(2)/NO(3) production regardless of phase or fragment. L-NOARG and AMT lowered NO(2)/NO(3) production in both fragments on Day 0 and Days 2-3. The possible role of TNFalpha, NO or PGs on the oviductal contractility during the early-luteal phase was also examined. Neither TNFalpha nor NONOate influenced contractility in either fragment. Although PGF(2alpha) stimulated the contraction in both fragments, PGE(2) decreased it. When taken together, TNFalpha seems to play some role as a modulator of PGF(2alpha) and PGE(2) production and for transferring the embryo from the oviduct to the uterus by stimulating NO production in the bovine oviduct.

Lysophosphatidic acid stimulates prostaglandin E2 production in cultured stromal endometrial cells through LPA1 receptor

Lysophosphatidic acid (LPA) has been shown to be a potent modulator of prostaglandin (PG) secretion during the luteal phase of the estrous cycle in the bovine endometrium in vivo. The aims of the present study were to determine the cell types of the bovine endometrium (epithelial or stromal cells) responsible for the secretion of PGs in response to LPA, the cellular, receptor, intracellular, and enzymatic mechanisms of LPA action. Cultured bovine epithelial and stromal cells were exposed to LPA (10(-5)-10(-9) M), tumor necrosis factor alpha (TNFalpha; 10 ng/mL) or oxytocin (OT; 10(-7) M) for 24 h. LPA treatment resulted in a dose-dependent increase of PGE(2) production in stromal cells, but not in epithelial cells. LPA did not influence PGF(2alpha) production in stromal or epithelial cells. To examine which type of LPA G-protein-coupled receptor (LP-GPCR; LPA1, LPA2, or LPA3) is responsible for LPA action, stromal cells were preincubated with three selected blockers of LPA receptors: NAEPA, DGPP, and Ki16425 for 0.5 h, and then stimulated with LPA. Only Ki16425 inhibited the stimulatory effect of LPA on PGE(2) production and cell proliferation in the stromal cells. LPA-induced intracellular calcium ion mobilization was also inhibited only by Ki16425. Finally, we examined whether LPA-induced PGE(2) synthesis in stromal cells is via the influence on mRNA expression for the enzymes responsible for PGE(2) synthesis-PGE(2) synthase (PGES) and PG-endoperoxide synthase 2 (PTGS2). We demonstrated that the stimulatory effect of LPA on PGE(2) production in stromal cells is via the stimulation of PTGS2 and PGES mRNA expression in the cells. The overall results indicate that LPA stimulates PGE(2) production, cell viability, and intracellular calcium ion mobilization in cultured stromal endometrial cells via Ki16425-sensitive LPA1 receptors. Moreover, LPA exerts a stimulatory effect on PGE(2) production in stromal cells via the induction of PTGS2 and PGES mRNA expression.

Lysophosphatic acid modulates prostaglandin secretion in the bovine endometrial cells differently on days 8-10 of the estrous cycle and early pregnancy

Lysophosphatidic acid (LPA) is becoming a new player in regulation of the reproductive processes of domestic animals. In the present study, we examined whether LPA modulates prostaglandin (PG) synthesis in the bovine endometrium at the time of the early maternal pregnancy recognition compared with the respective days of the estrous cycle and the enzymatic mechanism of this action. Bovine epithelial and stromal endometrial cells isolated from the uteri on days 8-10 of the estrous cycle and pregnancy were cultured with LPA for 24 h. LPA increased PGE(2) production in stromal cells during the estrous cycle and early pregnancy. On days 8-10 of pregnancy, LPA inhibited PGF(2alpha) production in epithelial cells. LPA stimulated PGES mRNA expression in stromal cells during both examined phases and inhibited PGFS mRNA expression in epithelial cells on days 8-10 of pregnancy. The overall results indicate that LPA may serve as a luteotropic factor during the luteal phase of the estrous cycle and early pregnancy stimulating PGE(2) synthesis and mRNA expression for PGES in stromal cells. Moreover, during early pregnancy, LPA might protect bovine CL and early embryo development by decreasing PGF(2alpha) synthesis and mRNA expression for PGFS in the epithelial cells of the bovine endometrium.

Acute changes in circulating concentrations of progesterone and nitric oxide and partial pressure of oxygen during prostaglandin F2alpha-induced luteolysis in cattle

To examine whether oxygen (O(2)) and nitric oxide (NO) are temporally associated with the acute changes in luteal function during luteolysis, we determined the real-time changes in the circulating concentrations of progesterone (P4) and nitrite/nitrate (the stable metabolites of NO) and the partial pressure of oxygen (pO(2)) during prostaglandin F(2alpha) (PGF(2alpha))-induced luteolysis in cattle. Catheters for frequent blood sample collection were inserted into the ovarian vein (OV), jugular vein (JV) and aorta abdominalis (AA) in 12 cows on Day 9 of the oestrous cycle (oestrus=Day 0). On Day 10, the cows were randomly divided into two groups and treated with a luteolytic dose of a PGF(2alpha) analogue or saline solution (control). Blood samples were collected at -2, -1, 0, 0.25, 0.5, 0.75, 1 and 2 h and then at 2-h intervals until 12 h after treatment (0 h). Injection of a PGF(2alpha) induced a significant decrease in the concentrations of P4 in OV plasma within 2 h. The decrease in P4 concentrations was preceded by an increase in the NO concentrations in the blood collected from OV, JV and AA. Basal pO(2) was significantly higher in OV blood than in JV blood (P<0.05). PGF(2alpha) injection increased pO(2) in OV blood between 0.5 and 2 h. These results demonstrate that PGF(2alpha) induced an acute increase in pO(2) and NO in the ovarian circulation and suggest that O(2) and NO are involved in the early events of CL regression, including inhibition of P4 secretion and output, in cattle.

Lysophosphatic acid modulates prostaglandin secretion in the bovine uterus

Lysophosphatidic acid (LPA) modulates prostaglandin (PG) synthesis via LPA receptor 3 (LPAR3) in the murine endometrium. The lack of functional LPAR3 in mice may lead to embryo mortality. In the present study, we examined the role of LPA in the bovine uterus. We confirmed that LPA is locally produced and released from the bovine endometrium. Moreover, there are enzymes involved in LPA synthesis (phospholipase (PL) D(2) and PLA2G1B) in the bovine endometrium during estrous cycle and early pregnancy. Expression of the receptor for LPA (LPAR1) was positively correlated with the expression of PGE(2) synthase (PGES) and negatively correlated with the expression of PGF(2alpha) synthase (aldose reductase with 20 alpha-hydroxysteroid dehydrogenase activity - PGFS) during early pregnancy. In vivo LPA induced P4 and PGE(2) secretion was inhibited by LPAR1 antagonist (Ki16425). The overall results indicate that LPA is locally produced and released from the bovine endometrium. Moreover, LPAR1 gene expression in the endometrium during the estrous cycle and early pregnancy indicates that LPA may play autocrine and/or paracrine roles in the bovine uterus. LPAR1 gene expression is positively correlated with the expression of the enzyme responsible for luteotropic PGE(2) production (PGES) in endometrium. In cow, LPA stimulates P4 and PGE(2) secretion. Thus, LPA in the bovine reproductive tract may indirectly (via endometrium) or directly support corpus luteum action via the increase of P4 synthesis and the increase of PGE(2)/PGF(2)(alpha) ratio. It suggests that LPA may serve as an important factor in the maintenance of early pregnancy in cow.

Concentrations of isoflavones and their metabolites in the blood of pregnant and non-pregnant heifers fed soy bean

The present study compared the changes in isoflavones (daidzein and genistein) and their metabolite (equol and para-ethyl-phenol) concentrations in the blood plasma of cyclic and pregnant heifers after feeding with soy bean. Twelve healthy heifers were divided into three groups: cyclic heifers (days 8-12 of the estrous cycle; control group; n=4), an early pregnancy group (2 months pregnant; n=4) and a late pregnancy group (8 months pregnant; n=4). All heifers were fed a single dose of 2.5 kg of soy bean and then blood samples were taken from the jugular vein for 8 h at predetermined intervals. The concentrations of soy bean-derived isoflavones and their active metabolites were measured in the blood plasma on an HPLC system. In the blood plasma of the early- and late-pregnant heifers, we found lower concentrations and time-dependent decreases in daidzein and genistein in comparison to cyclic heifers (P<0.05). Moreover, we noticed significant increases of equol and para-ethyl-phenol in the blood plasma of the early-pregnant heifers (P<0.05). In contrast, in the blood plasma of the late-pregnant heifers, we did not find an increase in the isoflavone metabolite concentrations compared with the early-pregnant heifers (P>0.05). In conclusion, physiological status (cyclicity or pregnancy) of the females influenced the concentrations of isoflavone metabolites in the blood plasma of the heifers. The stage of pregnancy affects isoflavone absorption, biotransformation and metabolism differently and results in higher concentrations of active metabolites of isoflavones during early pregnancy in comparison to their lower concentrations during late pregnancy. Therefore, we surmise that cows are more sensitive to active isoflavone metabolite actions during early pregnancy than cyclic heifers and heifers in late pregnancy.

Effects of exogenous tumour necrosis factor-alpha on the secretory function of the bovine reproductive tract depend on tumour necrosis factor-alpha concentrations

The aim of study was to correlate tumour necrosis factor-alpha (TNF) infused doses used with the TNF concentrations achieved and with the secretory function of both the ovary and the uterus in cows. We evaluated the concentrations of progesterone (P4), prostaglandin (PG)F(2alpha), PGE(2) nitric oxide (NO) and TNF in the jugular vein and vena cava caudalis as parameters of exogenous TNF action on the female reproductive tract. Aortae abdominalis of cows (n = 18) were infused with saline or two doses of TNF (luteolytic--1 microg or luteotrophic--10 microg). In the peripheral blood, 1 microg TNF concentrations achieved within the range of 30-45 pg/ml, and 10 microg TNF provoked a sharp increase in achieved concentrations at a range of 250-450 pg/mL). The TNF concentrations achieved in vena cava caudalis were five to six times higher than that in peripheral blood (p < 0.001). One microgram TNF increased PGF(2alpha) and NO (p < 0.001) and decreased P4 (p < 0.05). The higher TNF dose stimulated P4 and PGE(2) (p < 0.01). TNF infusion at luteolytic dose achieved its concentrations at the physiological range previously observed in cows. Luteotrophic TNF dose achieved the concentrations in vena cava caudalis that are much higher than physiological level and were previously noted in pathological circumstances (i.e. mastitis, metritis).

Luteolytic effect of prostaglandin F 2 alpha on bovine corpus luteum depends on cell composition and contact

Prostaglandin F(2 alpha) (PGF(2 alpha)) is a main luteolytic factor in vivo; however, its direct luteolytic influence on steroidogenic cells of bovine corpus luteum (CL) is controversial and not fully understood. The aim of the study was to clarify PGF(2 alpha) action on bovine CL in different in vivo and in vitro conditions and to examine whether the contact among all main types of CL cells is necessary for luteolytic PGF(2 alpha) action. In experiment 1, the bovine CL (day 15 of the oestrous cycle) was perfused using in vivo microdialysis system with dinoprost (an analogue of PGF(2 alpha)) for 0.5 h. Dinoprost caused a short-time increase in progesterone (P4), whose concentration decreased thereafter (at 6-, 10-, 12- and 24-h after treatment). In experiment 2, the direct effect of PGF(2 alpha) on P4 accumulation in CL steroidogenic cells cultured in monolayer (day 15 of the cycle) was determined. PGF(2 alpha) after 24 h of incubation increased P4 accumulation in steroidogenic CL cells. In experiment 3 steroidogenic, endothelial CL and immune cells (day 15 of the cycle) were incubated with PGF(2 alpha) in cocultures for 24 h in glass tubes and the levels of P4, stable metabolites of nitric oxide (NO) and leukotriene (LT) C(4) were determined. Although PGF(2 alpha) treatment increased P4 secretion in homogeneous steroidogenic CL cell culture, the decrease in P4 secretion in cocultures of all types of CL cells was observed. The secretion of NO and LTC(4) increased after the treatment of PGF(2 alpha) both in pure cultures of CL cells and in cocultures. The interactions between endothelial and immune cells with steroidogenic CL cells are needed for luteolytic PGF(2 alpha) action within the bovine CL. Our results indicate that the cell coculture model, including the main types of CL cells, is the most approximate to study PGF(2 alpha) role in vitro.

Fas-mediated apoptosis is suppressed by calf serum in cultured bovine luteal cells

Calf serum (CS) is a common supplement used in cell culture. It has been suggested that CS contains substances protecting cells against apoptosis. To examine whether a culture system including CS is appropriate for studying apoptosis in bovine luteal cells, we examined the influence of CS on the expression of Fas, bcl-2 and bax gene. Since progesterone (P(4)) is known to be an anti-apoptotic factor in bovine luteal cells, the present study was carried out to examine the P(4) effect on apoptosis. Bovine mid-luteal cells were exposed to Fas ligand (Fas L) in the presence or in the absence of P(4) antagonist (onapristone, OP) in a basal medium (BM) containing 5% CS (BM-CS) or BM containing 0.1% BSA (BM-BSA). Although Fas L alone, OP alone or Fas L plus OP did not show any cytotoxic effect on the cells cultured in BM-CS, administration of OP or OP in combination with Fas L resulted in the killing of 30% and 55% of the cells cultured in BM-BSA medium, respectively (p<0.05). Concomitantly, CS inhibited bax mRNA expression and stimulated bcl-2 expression in the cells (p<0.05). Moreover, in the cells cultured with BM-CS, Fas mRNA expression was smaller than that of cells incubated in BM-BSA medium (p<0.05). The overall results suggest that CS suppressed Fas-mediated cell death in cultured bovine luteal cells by promoting the ratio of bcl-2 to bax expression and by inhibiting Fas expression. Therefore, it may be suggested that CS contains such anti-apoptotic substances (growth factors) amplifying the cell survival pathways in the bovine corpus luteum (CL) in vitro.

Infusion of exogenous tumor necrosis factor dose dependently alters the length of the luteal phase in cattle: differential responses to treatment with indomethacin and L-NAME, a nitric oxide synthase inhibitor

We examined whether prostaglandins (PGs) and nitric oxide (NO) mediate tumor necrosis factor (TNF) actions in the estrus cycle. On Day 14 of the cycle, the following solutions were infused into the aorta abdominalis of a total of 51 heifers (Experiments 1 and 2): saline; 1 or 10 microg of TNF; 480 mg indomethacin (INDO), an inhibitor of prostaglandin H synthase; 800 mg L-NAME, an inhibitor of NO synthase; and TNF (1 or 10 microg) in combination with INDO or L-NAME. TNF at 1 microg infused directly into aorta abdominalis increased the level of PGF(2alpha) and decreased the level of progesterone (P4) in the peripheral blood and shortened the estrus cycle. The high TNF dose stimulated P4 and PGE(2) and prolonged the corpus luteum (CL) lifespan. INDO blocked the effects of both TNF doses on the CL lifespan and hormone output. L-NAME completely blocked the effects of the luteolytic TNF dose, whereas the effects of the luteotropic TNF dose were not inhibited. In Experiment 3 (Day 14), saline or different TNF doses were infused into the jugular vein (n = 9) or into the uterine lumen (n = 18). The CL lifespans of the different groups were not different when TNF was infused into the jugular vein. Although high TNF doses (1 and 10 microg) infused into the uterine lumen prolonged the CL lifespan, low doses (0.01 and 0.1 microg) induced premature luteolysis. We suggest that the actions of exogenous TNF on the CL lifespan depend on PG synthesis stimulated by TNF in the uterus. TNF at low concentrations initiates a positive cascade between uterine PGF(2alpha) and various luteolytic factors, including NO, to complete premature luteolysis. PGE(2) is a good candidate mediator of the luteotropic actions of exogenous TNF action.

Phyto- and endogenous estrogens differently activate intracellular calcium ion mobilization in bovine endometrial cells

The main purpose of this study was to check whether phyto- and endogenous estrogens influence calcium ion mobilization [Ca(2+)](i) in bovine endometrial cells and whether this action is connected with biological effects i.e. prostaglandin (PG)F(2alpha) production. In our study we used two calcium measurement methods by comparing the microscopic method with widely used quantitative - spectrofluorometric method of [Ca(2+)](i) measurement. We also wanted to confirm whether visualization of calcium ion [Ca(2+)](i) in cells using microscopic method supported by micro image analysis (Micro Image Olympus system) reflects real, qualitative changes in the ion concentration. In both methods a cell-permeable form of fluorescent [Ca(2+)](i) indicator Fura-2 was used. Cultured bovine endometrial epithelial and stromal cells influenced by phorbol-2-myristate-13-acetate (PMA; positive control), estradiol 17-beta (E(2); endogenous estrogen) and active metabolites of phytoestrogens (environmental estrogens) were used as a model to study PGF(2alpha) secretion and [Ca(2+)](i) mobilization in the cells. Equol and para-ethyl-phenol in doses of 10(-8)-10(-6) M increased PGF(2alpha) concentration both in epithelial and stromal cells (P<0.05). In both methods, equol and para-ethyl-phenol did not cause intracellular [Ca(2+)](i) mobilization in epithelial and stromal cells (P>0.05). Both methods revealed that only E(2) and PMA induced intracellular [Ca(2+)](i) mobilization in epithelial and stromal cells (P<0.05). The results of both methods were highly correlated (P<0.001; r=0.82 for epithelial cells and r=0.89 for stromal cells). In conclusion, both methods gave approximately the same results and showed that phytoestrogens, in contrast to PMA and E(2), did not cause intracellular [Ca(2+)](i) mobilization in endometrial cells. The obtained results proved that the [Ca(2+)](i) visualization method supported by micro image analysis can produce similar results to the spectrofluorometric method.