Oleic acid in the modulation of oocyte and preimplantation embryo development

Fatty acid supplementation during warming improves pregnancy outcomes after frozen blastocyst transfers: a propensity score-matched study

This study aimed to examine the viability of human blastocysts after warming with fatty acids (FAs) using an in vitro outgrowth model and to assess pregnancy outcomes after a single vitrified-warmed blastocyst transfer (SVBT). For the experimental study, we used 446 discarded vitrified human blastocysts donated for research purposes by consenting couples. The blastocysts were warmed using FA-supplemented (FA group) or non-FA-supplemented (control group) solutions. The outgrowth area was significantly larger in the FA group (P = 0.0428), despite comparable blastocyst adhesion rates between the groups. Furthermore, the incidence of outgrowth degeneration was significantly lower in the FA group than in the control group (P = 0.0158). For the clinical study, we retrospectively analyzed the treatment records of women who underwent SVBT in natural cycles between January and August 2022. Multiple covariates that affected the outcomes were used for propensity score matching as follows: 1342 patients in the FA group were matched to 2316 patients in the control group. Pregnancy outcomes were compared between the groups. The rates of implantation, clinical pregnancy, and ongoing pregnancy significantly increased in the FA group after SVBTs (P = 0.0091-0.0266). These results indicate that warming solutions supplemented with FAs improve blastocyst outgrowth and pregnancy outcomes after SVBTs.

Low-input lipidomics reveals lipid metabolism remodelling during early mammalian embryo development

Lipids are indispensable for energy storage, membrane structure and cell signalling. However, dynamic changes in various categories of endogenous lipids in mammalian early embryonic development have not been systematically characterized. Here we comprehensively investigated the dynamic lipid landscape during mouse and human early embryo development. Lipid signatures of different developmental stages are distinct, particularly for the phospholipid classes. We highlight that the high degree of phospholipid unsaturation is a conserved feature as embryos develop to the blastocyst stage. Moreover, we show that lipid desaturases such as SCD1 are required for in vitro blastocyst development and blastocyst implantation. One of the mechanisms is through the regulation of unsaturated fatty-acid-mediated fluidity of the plasma membrane and apical proteins and the establishment of apical-basal polarity during development of the eight-cell embryo to the blastocyst. Overall, our study provides an invaluable resource about the remodelling of the endogenous lipidome in mammalian preimplantation embryo development and mechanistic insights into the regulation of embryogenesis and implantation by lipid unsaturation.

GC-MS Analysis of Bioactive Compounds Extracted from Plant Rhazya stricta Using Various Solvents

Worldwide, human beings have traditionally employed many folkloric herbal resources as complementary and alternative remedies, and these remedies have played a pivotal role in modern medicines for many decades, as scientists have used them to develop drugs. We studied the effects of employing solvents with varying polarity on the yields of phytochemical components extracted from the plant Rhazya stricta. We used chloroform-methanol (1:1), methanol, ethanol, diethyl ether, and ethyl acetate as extraction solvents. The results showed that the efficiencies of the solvents at extracting phytochemical compounds were in this order: chloroform-methanol < ethanol < methanol < diethyl ether < ethyl acetate extract. The chloroform-methanol extract produced the highest concentration of phenolic and flavonoid contents among the five solvents tested (13.3 mg GAE/g DM and 5.43 CE/g DM). The yields of the extracted phytochemical compounds ranged from 47.55 to 6.05%. The results revealed that the properties of the extraction solvents considerably impacted the extraction yield and the phytochemical components of the R. stricta extract. Furthermore, compared with the other solvents, the chloroform-methanol extraction led to the highest yield (47.55%) and to more phytochemical substances being extracted. The aim of this study is to investigate the phytochemical compounds extracted from R. stricta with different solvents that have different polarities.

Metabolic signature of spent culture media shows lipid metabolism as a determinant of pregnancy outcomes

In the present study, we investigated the spent culture media of in vitro produced (IVP) bovine embryos which did (group Pregnant) or did not (group Non-pregnant) establish pregnancy after transfer. For that purpose, IVP embryos on D5 were transferred to individual droplets for the last 48 h of culture. Embryos at the blastocyst stage were then transferred to synchronized recipients, while respective culture media drops were collected and evaluated individually. The list of metabolites present in spent culture media was obtained by electrospray ionization mass spectrometry (ESI-MS) and analysed with Metaboanalyst® to characterize the metabolic profile of each group. The spectrometric analysis showed that pathways related to lipid metabolism, particularly fatty acids degradation via beta-oxidation, were more present in the Pregnant group whereas no significant pathway was identified in the group Non-pregnant. By using this method, we were able to identify a metabolic signature in culture media that allows for a better comprehension of preferential metabolic routes taken by the most viable embryos. These findings offer great insights into the biochemistry of embryo development and reveal a potential target for the development of better-quality IVP systems, as well as tools to identify bovine embryos with greater chances to establish and maintain pregnancy.

Mechanism of Guilu Erxian ointment based on targeted metabolomics in intervening in vitro fertilization and embryo transfer outcome in older patients with poor ovarian response of kidney-qi deficiency type

OBJECTIVE

To study the effect of Guilu Erxian ointment on the outcome of IVF-ET in older patients with poor ovarian response infertility of kidney-qi deficiency type, and to verify and analyze the mechanism of action of traditional Chinese medicine on improving older patients with poor ovarian response infertility of kidney-qi deficiency type from the perspective of metabolomics using targeted metabolomics technology, identify the related metabolic pathways, and provide metabolic biomarker basis and clinical treatment ideas for improving older patients with poor ovarian response infertility.

METHODS

This study was a double-blind, randomized, placebo-controlled trial, and a total of 119 infertile patients who underwent IVF-ET at Shandong Center for Reproduction and Genetics of Integrated Traditional Chinese and Western Medicine were selected. Eighty older patients with infertility undergoing IVF were randomly divided into older treatment group and older placebo group, and another 39 young healthy women who underwent IVF-ET or ICSI due to male factors were selected as the normal control group. Flexible GnRH antagonist protocol was used for ovulation induction in all three groups, and Guilu Erxian ointment and placebo groups started taking Guilu Erxian ointment and placebo from the third day of menstruation until IVF surgery. And ultra-high performance liquid chromatography-triple quadrupole mass spectrometer (UHPLC-QTRAP MS) was used to detect metabolites in the three groups of samples.

RESULTS

Compared with the placebo group, the number of oocytes retrieved, 2PN fertilization, high-quality embryos, total number of available embryos and estrogen on HCG day were increased in the treatment group, and the differences were statistically significant (P > 0.05), but the clinical pregnancy rate of fresh embryos and frozen embryos were not statistically significant (P > 0.05). The results of targeted metabolomics analysis showed that follicular fluid in the treatment group clustered with the normal young group and deviated from the placebo group. A total of 55 significant differential metabolites were found in the follicular fluid of older patients with poor ovarian response of kidney-qi deficiency type and patients in the normal young group, after Guilu Erxian ointment intervention, Metabolites such as L-Aspartic acid, Glycine, L-Serine, Palmitoleic Acid, Palmitelaidic acid, L-Alanine, Gamma-Linolenic acid, Alpha-Linolenic Acid, and N-acetyltryptophan were down-regulated, mainly involving amino acid metabolism and fatty acid metabolism.

CONCLUSION

Guilu Erxian ointment can effectively improve the clinical symptoms and IVF outcomes of older patients with poor ovarian response of kidney-qi deficiency type. There were differences in follicular fluid metabolites between older patients with poor ovarian response of kidney-qi deficiency type and normal women. L-Aspartic acid, L-Alanine, Aminoadipic acid, L-Asparagine, L-Arginine, L-Serine, Gamma- Linolenic acid, Pentadecanoic acid and Alpha-Linolenic Acid are closely related to older patients with poor ovarian response due to deficiency of kidney-qi and may be inferred as biomarkers. The mechanism of Guilu Erxian ointment intervention may be mainly through amino acid metabolism and fatty acid metabolism regulation.

Effects of CRISPR/Cas9-mediated stearoyl-Coenzyme A desaturase 1 knockout on mouse embryo development and lipid synthesis

Background

Lipid synthesis is an indispensable process during embryo and growth development. Abnormal lipid synthesis metabolism can cause multiple metabolic diseases including obesity and hyperlipidemia. Stearoyl-Coenzyme A desaturase 1 (SCD1) is responsible for catalyzing the synthesis of monounsaturated fatty acids (MUFA) and plays an essential role in lipid metabolism. The aim of our study was to evaluate the effects of SCD1 on embryo development and lipid synthesis in a knockout mice model.

Methods

We used the CRISPR/Cas9 system together with microinjection for the knockout mouse model generation. Ten-week-old female C57BL/6 mice were used for zygote collection. RNase-free water was injected into mouse zygotes at different cell phases in order to select the optimal time for microinjection. Five sgRNAs were designed and in vitro transcription was performed to obtain sgRNAs and Cas9 mRNA. RNase-free water, NC sgRNA/Cas9 mRNA, and Scd1 sgRNA/Cas9 mRNA were injected into zygotes to observe the morula and blastocyst formation rates. Embryos that were injected with Scd1 sgRNA/Cas9 mRNA and developed to the two-cell stage were used for embryo transfer. Body weight, triacylglycerol (TAG), and cholesterol in Scd1 knockout mice serum were analyzed to determine the effects of SCD1 on lipid metabolism.

Results

Microinjection performed during the S phase presented with the highest zygote survival rate (P < 0.05). Of the five sgRNAs targeted to Scd1, two sgRNAs with relatively higher gene editing efficiency were used for Scd1 knockout embryos and mice generation. Genome sequence modification was observed at Scd1 exons in embryos, and Scd1 knockout reduced blastocyst formation rates (P < 0.05). Three Scd1 monoallelic knockout mice were obtained. In mice, the protein level of SCD1 decreased (P < 0.05), and the body weight and serum TAG and cholesterol contents were all reduced (P < 0.01).

Glutathione deficiency decreases lipid droplet stores and increases reactive oxygen species in mouse oocytes†

Glutathione (GSH) is a tripeptide thiol antioxidant that has been shown to be important to overall reproductive health. Glutamate cysteine ligase, the rate-limiting enzyme in GSH synthesis consists of a catalytic and a modifier (GCLM) subunit. We previously showed that oxidative stress in the ovary and oocytes of Gclm-/- mice is associated with accelerated age-related decline in ovarian follicles and decreased female fertility due to preimplantation embryonic mortality. Mammalian preimplantation development is a highly regulated and energy-intensive process that primarily relies on coordination between lipid droplets (LDs) and mitochondria to maintain cellular homeostasis. In this study, we hypothesized that GSH deficiency in oocytes increases oxidative stress, leading to increased mitochondrial dysfunction and decreased LD consumption, thereby decreasing oocyte developmental competence. We observed that Gclm-/- oocytes have increased oxidative stress, primarily in the form of mitochondrial superoxide and decreased subcortical mitochondrial clusters. Further, Gclm-/- oocytes have decreased mitochondrial membrane potential (ΔΨm) compared with Gclm+/+. We surmise this is likely due to the decreased availability of LDs, as we observed a significant decrease in LD content in Gclm-/- oocytes compared with Gclm+/+. The decreased oocyte LD content is likely related to an altered serum lipidome, with Gclm-/- serum having relatively lower unsaturated fatty acids and triglycerides than that of Gclm+/+ and Gclm+/- females. Altogether these data support that decreased LDs and increased oxidative stress are primary drivers of decreased oocyte developmental competence in GSH-deficient oocytes.

Lipid metabolism and endometrial receptivity

BACKGROUND

Obesity has now been recognized as a high-risk factor for reproductive health. Although remarkable advancements have been made in ART, a considerable number of infertile obese women still suffer from serial implantation failure, despite the high quality of embryos transferred. Although obesity has long been known to exert various deleterious effects on female fertility, the underlying mechanisms, especially the roles of lipid metabolism in endometrial receptivity, remain largely elusive.

OBJECTIVE AND RATIONALE

This review summarizes current evidence on the impacts of several major lipids and lipid-derived mediators on the embryonic implantation process. Emerging methods for evaluating endometrial receptivity, for example transcriptomic and lipidomic analysis, are also discussed.

SEARCH METHODS

The PubMed and Embase databases were searched using the following keywords: (lipid or fatty acid or prostaglandin or phospholipid or sphingolipid or endocannabinoid or lysophosphatidic acid or cholesterol or progesterone or estrogen or transcriptomic or lipidomic or obesity or dyslipidemia or polycystic ovary syndrome) AND (endometrial receptivity or uterine receptivity or embryo implantation or assisted reproductive technology or in vitro fertilization or embryo transfer). A comprehensive literature search was performed on the roles of lipid-related metabolic pathways in embryo implantation published between January 1970 and March 2022. Only studies with original data and reviews published in English were included in this review. Additional information was obtained from references cited in the articles resulting from the literature search.

OUTCOMES

Recent studies have shown that a fatty acids-related pro-inflammatory response in the embryo-endometrium boundary facilitates pregnancy via mediation of prostaglandin signaling. Phospholipid-derived mediators, for example endocannabinoids, lysophosphatidic acid and sphingosine-1-phosphate, are associated with endometrial receptivity, embryo spacing and decidualization based on evidence from both animal and human studies. Progesterone and estrogen are two cholesterol-derived steroid hormones that synergistically mediate the structural and functional alterations in the uterus ready for blastocyst implantation. Variations in serum cholesterol profiles throughout the menstrual cycle imply a demand for steroidogenesis at the time of window of implantation (WOI). Since 2002, endometrial transcriptomic analysis has been serving as a diagnostic tool for WOI dating. Numerous genes that govern lipid homeostasis have been identified and, based on specific alterations of lipidomic signatures differentially expressed in WOI, lipidomic analysis of endometrial fluid provides a possibility for non-invasive diagnosis of lipids alterations during the WOI.

WIDER IMPLICATIONS

Given that lipid metabolic dysregulation potentially plays a role in infertility, a better understanding of lipid metabolism could have significant clinical implications for the diagnosis and treatment of female reproductive disorders.

Oleic acid reduces steroidogenesis by changing the lipid type stored in lipid droplets of ovarian granulosa cells

Background

Oleic acid is an abundant free fatty acid present in livestock that are in a negative energy-balance state, and it may have detrimental effects on female reproduction and fertility. Oleic acid induces lipid accumulation in bovine granulosa cells, which leads to a foam cell-like morphology and reduced steroidogenesis. However, why oleic acid increases lipid accumulation but decreases steroidogenesis remains unclear. This study focused on oleic acid’s effects on lipid type and steroidogenesis.

Results

Oleic acid increased the lipid accumulation in a concentration-dependent manner and mainly increased the triglyceride level and decreased the cholesterol ester level. Oleic acid also led to a decline in estradiol and progesterone production in porcine granulosa cells in vitro. In addition, oleic acid up-regulated the expression of CD36 and diacylglycerol acyltransferase 2, but down-regulated the expression of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, scavenger receptor class B member 1 and acetyl-Coenzyme A acetyltransferase 2, as well as steroidogenesis-related genes, including cytochrome P450 family 11 subfamily A member 1, cytochrome P450 family 19 subfamily A member 1 and 3 as well as steroidogenic acute regulatory protein at the mRNA and protein levels. An oleic acid-rich diet also enhanced the triglyceride levels and reduced the cholesterol levels in ovarian tissues of female mice, which resulted in lower estradiol levels than in control-fed mice. Compared with the control, decreases in estrus days and the numbers of antral follicles and corpora lutea, as well as an increase in the numbers of the atretic follicles, were found in the oleic acid-fed female mice.

Conclusions

Oleic acid changed the lipid type stored in lipid droplets of ovarian granulosa cells, and led to a decrease in steroidogenesis. These results improve our understanding of fertility decline in livestock that are in a negative energy-balance state.

Fatty acids intake and outcomes of assisted reproduction in women referring to an Italian Fertility Service: cross sectional analysis of a prospective cohort study

BackgroundInfertility involves 15% of couples in Italy and approximately 10-12% worldwide.Focusing on female fertility, it can underline multiple causes, among them the diet has a great influence. Methods We investigated whether the consumption of some fatty acids affects four outcomes of the assisted reproduction techniques. From September 2014 to December 2016, women referring to our Italian fertility unit, eligible for assisted reproduction techniques, were invited to participate. Information on dietwere recorded through a validated food frequency questionnaire. Results494 women were included, of whom95% achieved good quality oocytes, 87% resulted in embryo transfer, 32.0%in clinical pregnancies, and 24.5% in pregnancy at term.The fourth quartile of saturated fatty acids consumption, compared to the first one, showed an association with clinical pregnancy (adjusted relative risk 0.67, 95% confidence interval 0.45 to 1.00, p=0.0491). Some associations emerge accounting for confounders. Age was associated with clinical pregnancy and pregnancy at term in the models considering all fatty intakes and food groups variables but was not associated with oocytes quality and embryo transfer. Physical activity was associated with clinical pregnancy. ConclusionsThere is biologic plausibility of the effect of omega-3 and omega-6 polyunsaturated fatty acids on oocyte development via eicosanoids synthesis, even if our results showed limited associations.Future research is aimed to measure serum levels of fatty acids and investigate the assisted reproduction techniques' outcomes. This article is protected by copyright. All rights reserved.

Dietary Fatty Acid Intakes and the Outcomes of Assisted Reproductive Technique in Infertile Women

Background

The purpose of this study was evaluating the relationship between fatty acid (FA) intakes and the Assisted Reproductive Technique (ART) outcomes in infertile women.

Methods

In this descriptive longitudinal study, a validated food frequency questionnaire (FFQ) was used to measure dietary intakes among 217 women with primary infertility seeking ART treatments at Isfahan Fertility and Infertility Center, Isfahan, Iran. The average number of total and metaphase II (MII) oocytes, the fertilization rate, the ratio of good and bad quality embryo and biochemical and clinical pregnancy were assessed. Analyses were performed using mean, standard deviation, Chi-square test, ANOVA, ANCOVA, logistic regression.

Results

A total of 140 women were finally included in the study. There was a positive relationship between the average number of total and MII oocytes and the amount of total fatty acids (TFAs), saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), linoleic acids, linolenic acids, and oleic acids intakes, while eicosapentaenoic acids (EPAs) and docosahexaenoic acids (DHAs) intakes had an inverse relationship. Consuming more amounts of TFAs, SFAs, PUFAs, MUFAs, linoleic acids, and oleic acids was associated with the lower fertilization rate, whereas the consumption of linolenic acids and EPAs increased the fertilization rate. The ratio of good quality embryo was directly affected by the amount of PUFAs intakes. Additionally, there was a negative correlation between the amount of SFAs intakes and the number of pregnant women.

Conclusion

TFAs, SFA, PUFA, and MUFA intakes could have both beneficial and adverse impacts on ART outcomes.

Unsaturated Fatty Acid Intake During Periconception and Incidence of Achieving Pregnancy: A Systematic Review and Meta-Analysis

Background: Previous studies suggest that maternal diets enriched in unsaturated fatty acids may have a positive effect on pregnancy success. The aim of the present study was to conduct a systematic review and meta-analysis to evaluate whether increased dietary intake of polyunsaturated fatty acids (PUFAs) or monounsaturated fatty acids (MUFAs) during the periconception period has beneficial effects on the achievement of pregnancy in women.

Methods: The electronic databases PubMed, Medline and Cochrane Central Register, as well as references in related review articles, were searched to find studies assessing the effects of unsaturated fatty acid dietary intake during the periconception period on the achievement of pregnancy in women. Pregnancy was confirmed by high levels of hCG (biochemical means) and ultrasound confirmation of a gestational sac and heartbeat (clinical means).

Results: For the meta-analysis evaluating the effects of periconceptional diets enriched in PUFAs on pregnancy, four articles, providing data on 2,121 patients, were included. Results showed that periconceptional intake of PUFAs has no significant effects on achieving pregnancy compared to controls, according to both the fixed effects and random effects models (RR = 0.99, 95% CI 0.98–1.00). Further secondary analysis considering ω-6 and ω-3 PUFAs separately showed no significant effects on achieving pregnancy compared to controls. On the other hand, for the meta-analysis evaluating the effects of periconceptional diets enriched in MUFAs on achieving pregnancy, five articles, providing data on 2,473 patients, were included. Results showed that periconceptional dietary intake of MUFAs has significant effects on achieving pregnancy compared to controls according to the fixed effects model (RR = 1.03, 95% CI 1.01–1.06, p < 0.02) but not to the random effects model, due to heterogeneity. A secondary meta-analysis excluding one study which led to heterogeneity showed significant effects of MUFAs on achieving pregnancy compared to controls, according to both the fixed effects and random effects models (RR = 1.03, 95% CI 1.01–1.05, p < 0.02).

Conclusion: The meta-analysis of published clinical studies suggests that diets enriched in MUFAs, although not those enriched in PUFAs, may have a positive effect on pregnancy success as determined by HCG and ultrasonography.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42021239355, identifier: CRD42021239355.

The Differential Metabolomes in Cumulus and Mural Granulosa Cells from Human Preovulatory Follicles

This study evaluated the differences in metabolites between cumulus cells (CCs) and mural granulosa cells (MGCs) from human preovulatory follicles to understand the mechanism of oocyte maturation involving CCs and MGCs. CCs and MGCs were collected from women who were undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment. The differences in morphology were determined by immunofluorescence. The metabolomics of CCs and MGCs was measured by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) followed by quantitative polymerase chain reaction (qPCR) and western blot analysis to further confirm the genes and proteins involved in oocyte maturation. CCs and MGCs were cultured for 48 h in vitro, and the medium was collected for detection of hormone levels. There were minor morphological differences between CCs and MGCs. LC-MS/MS analysis showed that there were differences in 101 metabolites between CCs and MGCs: 7 metabolites were upregulated in CCs, and 94 metabolites were upregulated in MGCs. The metabolites related to cholesterol transport and estradiol production were enriched in CCs, while metabolites related to antiapoptosis were enriched in MGCs. The expression of genes and proteins involved in cholesterol transport (ABCA1, LDLR, and SCARB1) and estradiol production (SULT2B1 and CYP19A1) was significantly higher in CCs, and the expression of genes and proteins involved in antiapoptosis (CRLS1, LPCAT3, and PLA2G4A) was significantly higher in MGCs. The level of estrogen in CCs was significantly higher than that in MGCs, while the progesterone level showed no significant differences. There are differences between the metabolomes of CCs and MGCs. These differences may be involved in the regulation of oocyte maturation.

Associations between the exposure to organophosphate flame retardants during early pregnancy and the risk of spontaneous abortion based on metabolomics combined with tandem mass spectrometry

BACKGROUND

As potential substitutes for polybrominated diphenyl ethers (PBDEs), organophosphate flame retardants (OPFRs) have been frequently detected in the environment. They have been suggested to impair fetal growth and development in toxicological studies. However, there are few studies on their maternal effects before or during early pregnancy.

METHODS

This study was designed to investigate whether exposure to OPFRs before or during early pregnancy is associated with the risk of spontaneous abortion (SAB), using a nested case-control design based on the case data from clinical examinations in Shanghai, China. A total of 110 cases from this cohort project in 2019-2020 were included. The concentrations of OPFRs in maternal urine samples collected in early pregnancy were determined using Ultra high performance liquid chromatography- triple quadrupole mass spectrometer (UHPLC-MS/MS), and pregnancy outcomes were extracted from the medical records. Meanwhile, ultra high performance liquid chromatography time-of-flight mass spectrometer (UHPLC-Q-TOF/MS)-based metabonomics was used to obtain urine metabolic profiles of 110 women in early pregnancy.

RESULTS

According to the quantitative results, the content of bis(1-chloro-2-propyl)phosphate (BCIPP) in urine was significantly different between the SAB patients and the healthy pregnant women. Besides, metabolic profile analysis showed a significant difference in the urine metabolism profile in early pregnancy between SAB cases and controls. Twenty-five different metabolites were screened out, which showed different degrees of correlation with the urinary BCIPP concentration.

CONCLUSIONS

Based on these results, it suggests that there may be a certain correlation between BCIPP concentration in the urine and the risk of SAB from a metabolomics perspective, and its effect may be related to the metabolism of tryptophan and fatty acids.

Differential Metabolomics and Network Pharmacology Analysis of Silkworm Biotransformation between Mulberry Leaves and Silkworm Droppings

Silkworm droppings are the product of mulberry leaves digested by silkworm intestines, which are an important medicinal resource in traditional Chinese medicine (TCM). The contents of total fat, fat acids, crude protein, amino acids, and secondary metabolites of obtained mulberry leaves and silkworm droppings were analyzed by HPLC, GC-MS, and UHPLC-Q-TOF MS. The target genes and enriched pathways related to significantly changed compositions between mulberry leaves and silkworm droppings were analyzed by network pharmacology. High unsaturated C18 : 3 fatty acids were transformed to low unsaturated C18 : 1 from mulberry leaves to silkworm droppings. Only lysine and 17 mini-peptides had significantly higher content in silkworm droppings than in mulberry leaves. There were 36 common target genes or the different compounds between mulberry leaves and silkworm droppings. The main pathways of mulberry leaf were enriched in antivirus and anticancer properties, while the pathways of silkworm droppings were enriched in hormone regulation and signal transduction.

Genome wide effects of oleic acid on cultured bovine granulosa cells: evidence for the activation of pathways favoring folliculo-luteal transition

BACKGROUND

Metabolic stress, as negative energy balance on one hand or obesity on the other hand can lead to increased levels of free fatty acids in the plasma and follicular fluid of animals and humans. In an earlier study, we showed that increased oleic acid (OA) concentrations affected the function of cultured bovine granulosa cells (GCs). Here, we focus on genome wide effects of increased OA concentrations.

RESULTS

Our data showed that 413 genes were affected, of which 197 were down- and 216 up-regulated. Specifically, the expression of FSH-regulated functional key genes, CCND2, LHCGR, INHA and CYP19A1 and 17-β-estradiol (E2) production were reduced by OA treatment, whereas the expression of the fatty acid transporter CD36 was increased and the morphology of the cells was changed due to lipid droplet accumulation. Bioinformatic analysis revealed that associated pathways of the putative upstream regulators "FSH" and "Cg (choriogonadotropin)" were inhibited and activated, respectively. Down-regulated genes are over-represented in GO terms "reproductive structure/system development", "ovulation cycle process", and "(positive) regulation of gonadotropin secretion", whereas up-regulated genes are involved in "circulatory system development", "vasculature development", "angiogenesis" or "extracellular matrix/structure organization".

CONCLUSIONS

From these data we conclude that besides inhibiting GC functionality, increased OA levels seemingly promote angiogenesis and tissue remodelling, thus suggestively initiating a premature fulliculo-luteal transition. In vivo this may lead to impeded folliculogenesis and ovulation, and cause sub-fertility.

Oleic Acid Protects Caenorhabditis Mothers From Mating-Induced Death and the Cost of Reproduction

Reproduction comes at a cost, including accelerated death. Previous studies of the interconnections between reproduction, lifespan, and fat metabolism in C. elegans were predominantly performed in low-reproduction conditions. To understand how increased reproduction affects lifespan and fat metabolism, we examined mated worms; we find that a Δ9 desaturase, FAT-7, is significantly up-regulated. Dietary supplementation of oleic acid (OA), the immediate downstream product of FAT-7 activity, restores fat storage and completely rescues mating-induced death, while other fatty acids cannot. OA-mediated lifespan restoration is also observed in C. elegans mutants suffering increased death from short-term mating, and in mated C. remanei females, indicating a conserved role of oleic acid in post-mating lifespan regulation. Our results suggest that increased reproduction can be uncoupled from the costs of reproduction from somatic longevity regulation if provided with the limiting lipid, oleic acid.

Effects of fatty acid supplementation during vitrification and warming on the developmental competence of mouse, bovine and human oocytes and embryos

RESEARCH QUESTION

Does fatty acid supplementation in vitrification and warming media influence developmental competence in oocytes after vitrification and warming?

DESIGN

Mouse oocytes and four-cell embryos were vitrified and warmed with solutions supplemented with fatty acid and cultured to the blastocyst stage. To study lipid metabolism after vitrification, quantitative real-time polymerase chain reaction was used to analyse the expression of genes related to beta oxidation in mouse embryos vitrified and warmed with or without fatty acids. The effects of fatty acid supplementation in the warming solutions on the developmental competence of bovine and human embryos were analysed. Blastocyst outgrowth assay was used to evaluate the potential of human blastocysts for adhesion to fibronectin.

RESULTS

The neutral lipid content of mouse oocytes in the fatty acid 1% supplementation group was significantly higher than in the fatty acid 0% group (P = 0.0032). The developmental rate to the blastocyst stage was significantly higher in the fatty acid 1% group than in the fatty acid 0% group in mice (P = 0.0345). Fatty acid supplementation in warming solution upregulated Acaa2 and Hadha in mouse embryos. Fatty acids significantly improved the developmental ability of bovine embryos to the blastocyst stage (P = 0.0048). Warming with 1% fatty acid supplementation significantly increased the proportion of human blastocysts with morphological grade A inner cell mass (P = 0.0074) and trophectoderm (P = 0.0323).

CONCLUSIONS

Fatty acid supplementation in the warming solutions improved the developmental competence of vitrified-warmed mouse oocytes by activating the beta-oxidation pathway. Fatty acid supplementation enhanced the developmental rate of bovine embryos to the blastocyst stage and improved morphological characteristics of human embryos vitrified at the cleavage stage.

Metabolites Secreted by Bovine Embryos In Vitro Predict Pregnancies That the Recipient Plasma Metabolome Cannot, and Vice Versa

This work describes the use of mass spectrometry-based metabolomics as a non-invasive approach to accurately predict birth prior to embryo transfer (ET) starting from embryo culture media and plasma recipient. Metabolomics was used here as a predictive platform. Day-6 in vitro produced embryos developed singly in modified synthetic oviduct fluid culture medium (CM) drops for 24 h were vitrified as Day-7 blastocysts and transferred to recipients. Day-0 and Day-7 recipient plasma (N = 36 × 2) and CM (N = 36) were analyzed by gas chromatography coupled to the quadrupole time of flight mass spectrometry (GC-qTOF). Metabolites quantified in CM and plasma were analyzed as a function to predict pregnancy at Day-40, Day-62, and birth (univariate and multivariate statistics). Subsequently, a Boolean matrix (F1 score) was constructed with metabolite pairs (one from the embryo, and one from the recipient) to combine the predictive power of embryos and recipients. Validation was performed in independent cohorts of ETs analyzed. Embryos that did not reach birth released more stearic acid, capric acid, palmitic acid, and glyceryl monostearate in CM (i.e., (p < 0.05, FDR < 0.05, Receiver Operator Characteristic—area under curve (ROC-AUC) > 0.669)). Within Holstein recipients, hydrocinnamic acid, alanine, and lysine predicted birth (ROC-AUC > 0.778). Asturiana de los Valles recipients that reached birth showed lower concentrations of 6-methyl-5-hepten-2-one, stearic acid, palmitic acid, and hippuric acid (ROC-AUC > 0.832). Embryonal capric acid and glyceryl-monostearate formed F1 scores generally >0.900, with metabolites found both to differ (e.g., hippuric acid, hydrocinnamic acid) or not (e.g., heptadecanoic acid, citric acid) with pregnancy in plasmas, as hypothesized. Efficient lipid metabolism in the embryo and the recipient can allow pregnancy to proceed. Changes in phenolics from plasma suggest that microbiota and liver metabolism influence the pregnancy establishment in cattle.

Dynamics of lipid droplets in the endometrium and fatty acids and oxylipins in the uterine lumen, blood, and milk of lactating cows during diestrus

Our objective was to investigate the lipid content of uterus, blood plasma, and milk at early, mid, and late diestrus. Lactating cows (n = 30) had the estrous cycle and ovulation synchronized by administration of exogenous hormones. Cows were blocked by parity and assigned randomly to receive transcervical uterine flushing and biopsy on d 5 (early diestrus), 10 (mid diestrus) or 15 (late diestrus) of the estrous cycle. Flushing and endometrial biopsy were performed in the uterine horn ipsilateral to the corpus luteum. The recovered flushing was used for analyses of lipid composition by liquid chromatography-tandem mass spectrometry and the biopsy was used for investigation of lipid droplet abundance in endometrial cryosections using a neutral lipid fluorescent dye. In addition, blood and milk samples were collected from all cows on d 5, 10, and 15. All blood samples were used to measure the concentration of progesterone in plasma, and all milk samples were used to determine milk composition. Subsamples of blood plasma and milk were also used to evaluate the composition of fatty acids and oxylipins using the same methodology used for uterine flushing samples. The abundance of lipid droplets in the endometrium increased 1.9-fold from d 5 to 10, and 2-fold from d 10 to 15. Concentration of long-chain fatty acids and oxylipins in uterine flushing were, on average, 2.2 and 2.5 times greater in samples collected on d 15 compared with those collected on d 5 and 10. These differences were not observed in blood and milk, suggesting that accumulation of fatty acids and oxylipins in the uterus is regulated locally. In addition to concentration, the profile of individual fatty acids and oxylipins in uterine lumen changed substantially during diestrus. The main categories with increased abundance at late diestrus were mono- and polyunsaturated fatty acids, and oxylipins derived from arachidonic acid, dihomo-γ-linolenic acid, and docosahexaenoic acid. In conclusion, fatty acids and oxylipins accumulate in the uterine lumen during diestrus and might work as a mechanism to supply these lipids to the developing conceptus at late diestrus, when the onset of elongation occurs and substantial synthesis of biomass and cell signaling by lipid mediators are required.

Cystic fibrosis transmembrane conductance regulator in follicular fluid and cumulus cells and its relationship with age

Oocyte quality deteriorates with female age and numerous indicators of oocyte quality exist. In the present study, the levels of cystic fibrosis transmembrane conductance regulator (CFTR) in the follicular fluid (FF) and cumulus cells (CCs) of infertile females in 3 different age groups were assessed to determine the relationship between CFTR and female age. The general features of the 3 groups, including age, body mass index, infertility duration, basal hormone levels and the number of retrieved oocytes were compared. The FF CFTR levels of the 3 groups were also compared and multiple age-related indicators of oocyte quality were analyzed, including the estradiol levels on the human chorionic gonadotropin injection day, the morphologically normal oocyte rate and the available or high-quality embryo rate. Immunofluorescence and PCR analyses were performed to examine CFTR expression in CCs around oocytes. The results indicated differences in general features and several indicators of oocyte quality among the 3 groups and significant differences in CFTR. The FF CFTR level was positively correlated with age, which was confirmed by immunofluorescence and PCR. Collectively, these results indicated that CFTR expression in FF and CCs may be associated with oocyte quality based on the age of individuals undergoing the assisted reproduction technique.

Fatty acids of follicular fluid phospholipids and triglycerides display distinct association with IVF outcomes

RESEARCH QUESTION

Are triglyceride fatty acids in the follicular fluid associated with either follicular fluid phospholipid fatty acids or IVF outcomes and, if so, how are they associated?

DESIGN

In a prospective cross-sectional study, 70 women undergoing intracytoplasmic sperm injection were recruited. Follicular fluid phospholipids and triglycerides were separated by thin-layer chromatography. Fatty acids were measured using gas-liquid chromatography and flame ionization detection system.

RESULTS

Significant differences in fatty acid composition were observed between follicular fluid phospholipid and triglyceride fractions. Phospholipid stearic acid and n-3 polyunsaturated fatty acids, particularly alpha-linolenic acid, were negatively associated with the number of mature oocytes and cleaved embryos, whereas arachidonic acid was in direct correlation with cleavage rate per IVF cycle (β = 0.325, P = 0.022). In the case of triglyceride fraction, total monounsaturated fatty acids, oleic acid in particular, displayed significantly positive associations with the number of oocytes (β = 0.261, P = 0.043) and embryos (β = 0.310, P = 0.018). Furthermore, cleavage rate correlated inversely with palmitic acid (β = -0.359, P = 0.007) and directly with pentadecanoic acid (β = 0.378, P = 0.005). Most of these associations, however, were not independent of predictive fatty acids belonging to phospholipid fraction, according to multivariate analysis.

CONCLUSIONS

Fatty acid compositions of phospholipid and triglyceride fractions from human follicular fluid differentially correlate with IVF cycle parameters.

Oleic Acid Counters Impaired Blastocyst Development Induced by Palmitic Acid During Mouse Preimplantation Development: Understanding Obesity-Related Declines in Fertility

Obesity is associated with altered fatty acid profiles, reduced fertility, and assisted reproductive technology (ART) success. The effects of palmitic acid (PA), oleic acid (OA), and their combination on mouse preimplantation development, endoplasmic reticulum (ER) stress pathway gene expression, lipid droplet formation, and mitochondrial reactive oxygen species (ROS) were characterized. Two-cell stage mouse embryos collected from superovulated and mated CD1 females were placed into culture with KSOMaa medium, or PA alone or in combination with OA for 46 h. PA significantly reduced blastocyst development in a concentration-dependent manner, which was prevented by co-treatment with OA. PA and OA levels in mouse reproductive tracts were assessed by liquid chromatography coupled to mass spectrometry (LC-MS). LC-MS indicated higher concentrations of PA in the mouse oviduct than the uterus. Transcript analysis revealed that PA alone groups had increased ER stress pathway (ATF3, CHOP, and XBP1 splicing) mRNAs, which was alleviated by OA co-treatment. OA co-treatment significantly increased lipid droplet accumulation and significantly decreased mitochondrial ROS from PA treatment alone. PA treatment for only 24 h significantly reduced its impact on blastocyst development from the 2-cell stage. Thus, PA affects ER stress pathway gene expression, lipid droplet accumulation, and mitochondrial ROS in treated preimplantation embryos. These mechanisms may serve to offset free fatty acid exposure effects on preimplantation development, but their protective ability may be overwhelmed by elevated PA.

Partitioning of fatty acids into tissues and fluids from reproductive organs of ewes as affected by dietary phenolic extracts

Evaluation of dietary interventions with regard to fertility problems often observed in ruminant livestock is of global interest. Though the effects of polyphenol supplementation in ruminants on digestion and food quality are well described, the impact on reproductive tissues and fluids remains scarcely investigated. These compounds protect dietary unsaturated fatty acids (FA) from oxidation and biohydrogenation and thus saturation. In addition, modification of the expression of genes associated with FA metabolism may occur. Therefore, we characterized for the first time the FA profiles of reproductive tissues and fluids and investigated their potential modification by dietary polyphenols in 22 cyclic ewes. The animals were randomly divided into four groups and fed a basal diet of meadow hay and one of four concentrate types either non-supplemented (control) or supplemented with grape seed extract, Acacia mearnsii bark extract (13 g/kg dry matter (DM) each) or a combination of both (26 g/kg DM). After 10 weeks of feeding, the animals were slaughtered. Samples of reproductive (oviduct, uterus) and metabolically differently active tissues (liver, muscle, adipose) as well as of plasma and fluids from oviduct and uterus were analysed for their FA composition. In addition, the expression of lipid metabolic and antioxidant genes was analysed in all tissues except the adipose tissue. Fatty acid profiles in tissues and fluids as well as gene expression in tissues significantly differed between the different fluids and tissues. In contrast, only a few diet and matrix (fluid or tissue) × diet interactions were observed. Still, the FA profile of the uterus was the only one not at all affected by the diet. The mRNA expression was not affected by the diet for most of the genes investigated, which might in part be explained by the similar plasma polyphenol concentrations found at slaughter. Overall, our findings contribute to an improved understanding of the characteristic FA composition of reproductive tissues and fluids in sheep. In addition, the effect of polyphenols on different tissues, fluids and tissue gene expression has been confirmed as described in other animal species.

Alpha-Linolenic Acid: It Contribute Regulation of Fertilization Capacity and Subsequent Development by Promoting of Cumulus Expansion during Maturation

The objective of this study was to evaluate the effects of alpha-linolenic acid (ALA) during in vitro maturation (IVM) on cumulus expansion, nuclear maturation, fertilization capacity and subsequent development in porcine oocytes. The oocytes were incubated with 0, 25, 50, and 100 μM ALA. Cumulus expansion was measured at 22 h, and gene expresison and nuclear maturation were analyzed at 44 h after maturation. Then, mature oocytes with ALA were inseminated, and fertilization parameters and embryo development were evaluated. In results, both of cumulus expansion and nuclear maturation were increased in 50 μM ALA groups compared to control groups (p<0.05). However, expression of gap junction protein alpha 1 (GJA1, cumulus expansion-related gene), delta-6 desaturase (FADS1, fatty acid metabolism-related gene), and delta-5 desaturase (FADS2) mRNA in cumulus cells were reduced by 50 μM ALA treatment (p<0.05). Cleavage rate was enhanced in 25 and 50 μM ALA groups (p<0.05), especially, treatment of 50 μM ALA promoted early embryo develop to 4 and 8 cell stages (p<0.05). However, blastocyst formation and number of cells in blastocyst were not differ in 25 and 50 μM ALA groups. Our findings show that ALA treatment during maturation could improve nuclear maturation, fertilization, and early embryo development through enhancing of cumulus expansion, however, fatty acid metabolism- and cumulus expansion-related genes were down-regulated. Therefore, addition of ALA during IVM of oocytes could improve fertilization and developmental competence, and further studies regarding with the mechanism of ALA metabolism are needed.

Action mechanisms of n-3 polyunsaturated fatty acids on the oocyte maturation and developmental competence: Potential advantages and disadvantages

Infertility is a growing problem worldwide. Currently, in vitro fertilization (IVF) is widely performed to treat infertility. However, a high percentage of IVF cycles fails, due to the poor developmental potential of the retrieved oocyte to generate viable embryos. Fatty acid content of the follicular microenvironment can affect oocyte maturation and the subsequent developmental competence. Saturated and monounsaturated fatty acids are mainly used by follicle components as primary energy sources whereas polyunsaturated fatty acids (PUFAs) play a wide range of roles. A large body of evidence supports the beneficial effects of n-3 PUFAs in prevention, treatment, and amelioration of some pathophysiological conditions including heart diseases, cancer, diabetes, and psychological disorders. Nevertheless, current findings regarding the effects of n-3 PUFAs on reproductive outcomes in general and on oocyte quality more specifically are inconsistent. This review attempts to provide a comprehensive overview of potential molecular mechanisms by which n-3 PUFAs affect oocyte maturation and developmental competence, particularly in the setting of IVF and thereby aims to elucidate the reasons behind current discrepancies around this topic.