Fatty acid profile of blood plasma and oviduct and uterine fluid during early and late luteal phase in the horse

Mammalian embryo culture media: now and into the future

For over 70years, since the culture of the first mammalian embryo in vitro , scientists have undertaken studies to devise and optimise media to support the manipulation and culture of gametes and embryos. This area of research became especially active in the late 1970s onwards following the successful birth of the first human in vitro fertilised embryo. This review summarises some of the key advances in mammalian embryo culture media over time based on a greater understanding of the biochemical milieu of the reproductive tract. It highlights how learnings from studies in mice and agricultural species have informed human culture media compositions, in particular the inclusion of albumin, growth factors, cytokines, and antioxidants into contemporary culture media formulations, and how these advances may then in turn help to inform and guide development of in vitro culture systems used in other arenas, in particular agriculture. Additionally, it will highlight how the introduction of new technologies, such as timelapse, can influence current trends in media composition and usage that may see a return to a single step medium.

Differences of the Plasma Total Lipid Fraction from Pre-Foaling to Post-Foaling Period in Donkeys

Simple Summary

An association between increased metabolic demands and reduced dry matter intake is observed from late gestation to early lactation in donkeys. Furthermore, little is known about the nutritional and energy requirements of this period in animals. Changes in energy metabolism make donkeys more susceptible to metabolic diseases such as hyperlipemia, which is characterized by the mobilization of fatty acids from adipose tissue. A better knowledge of this period could improve animal husbandry, well-being, and health. The aim of this study was to analyze the plasma total lipid fraction, to highlight metabolic changes from the pre-foaling to post-foaling periods, using the gas chromatography technique. Our findings reveal a greater risk of metabolic disease in late gestation to early lactation in donkeys.

Abstract

The period from late gestation to early lactation is characterized by changes in energy metabolism. The aim of the current study was to analyze the plasma total lipid fraction using gas chromatography (GC) analysis, in order to highlight metabolic changes from the pre-foaling to post-foaling periods. Eleven pluriparous dairy jennies (mean age of 11.88 ± 3.79 years) belonging to the Amiata donkey breed were enrolled. Blood sampling was performed at 15 days before foaling (T0), and 15 (T1), 30 (T2), 60 (T3), and 90 (T4) days after foaling, for biochemical and GC analysis. A total of 37 fatty acids were identified in plasma samples: 4 medium chain (MCFA), 24 long chain (LCFA), and 9 very-long chain (VLCFA) fatty acids. Among them, 20 fatty acids changed significantly, and two fatty acid showed a trend toward significance. Furthermore, the LCFA, saturated, unsaturated, monounsaturated, and polyunsaturated ω-3 fatty acids changed significantly during the study period. The main alterations were between T0 and the other time points and appeared to be related to lipid metabolism, cellular structure and function, and inflammatory and immune responses. Our findings reveal greater energy requirements at the end of gestation compared to early lactation in donkeys.

Moderate differences in plasma leptin in mares have no effect on either the amino acid or the fatty acid composition of the uterine fluid

Female mammalian reproductive functions are closely linked to body condition and metabolic status. Energy homeostasis is regulated by endocrine hormones such as insulin, IGF-I, leptin and adiponectin via the hypothalamic-pituitary-adrenal axis. These metabolic hormones and their receptors are also expressed in reproductive tissues and the embryo. We investigated the relationship between circulating leptin and the fatty acid (FA) and amino acid (AA) composition of the equine uterine fluid (UF) and peripheral blood plasma (BP) by using a mass spectrometry-based approach. UF and BP were collected from ten broodmares on days 6 and 7 post ovulation, respectively. The mares were retrospectively assigned to two groups according to their BP leptin concentrations (high leptin (> 1.6 ng/ml) versus low leptin (<0.8 ng/ml)). Specific AA and FA compositions for BP and UF were found with different levels of respective metabolite abundances. The main FAs in BP were stearic, palmitic and linoleic acid. In UF, the three most abundant FAs were eicosapentaenoic, arachidonic and stearic acid. The AA profile of BP was dominated by glycine, glutamine, serine and alanine, which were likewise among the highly abundant AAs in UF. In UF, glutamic acid had by far the highest concentration. Therefore, BP leptin concentration within a physiological range do not seem to affect the specific FA nor the AA composition of the UF. The composition of the UF may therefore be mediated by local rather than by peripheral metabolic hormones.

Fatty Acid Profile of Blood Plasma at Mating and Early Gestation in Rabbit

The aim of this study was to analyse the fatty acid (FA) profile of blood plasma at mating and 72 hpm by gas chromatography. Moreover, the correlation between FA and ovulation rate, normal embryos and compacted morulae was estimated. Palmitic, linoleic, oleic and stearic were the highest FA concentrations at mating and 72 hpm. Most long chain saturated and PUFA were higher at 72 hpm than at mating, while MUFA were higher at mating. SFA, MUFA and PUFA were high and positively correlated. Correlation was 0.643 between MUFA at mating and ovulation rate, and 0.781 between MUFA and normal embryos, respectively. Compacted morulae were slightly correlated with SFA at mating (0.465). In conclusion, the FA profile of plasma varies depending on the reproductive cycle of the rabbit female, adapting to energetic requirements at mating and early gestation. Moreover, positive correlations are found between fatty acids and ovulation rate and embryo development and quality.

Amino acids activate mTORC1 to release roe deer embryos from decelerated proliferation during diapause

In mammals, embryo development can halt at the hatched blastocyst stage. Uniquely, proliferation of diapausing embryonic roe deer cells decelerates to a doubling time of 2 to 3 wk over a period of 4 mo. We highlight nutrient sensing as an important factor regulating embryonic developmental pace. The resumption of embryo development is characterized by an increase in uterine fluid mTORC1-activating amino acids, embryonic mTORC1 activity, and expression of metabolism and cell cycle genes. We propose selective mTORC1 inhibition via reduced estrogen signaling and high let-7 levels as mechanisms for slow cell cycle progression. We hypothesize that it is the lack of embryonic mTORC2 inhibition during embryonic diapause in the roe deer that enables the continuous decelerated rate of proliferation.

Embryonic diapause in mammals leads to a reversible developmental arrest. While completely halted in many species, European roe deer (Capreolus capreolus) embryos display a continuous deceleration of proliferation. During a 4-mo period, the cell doubling time is 2 to 3 wk. During this period, the preimplantation blastocyst reaches a diameter of 4 mm, after which it resumes a fast developmental pace to subsequently implant. The mechanisms regulating this notable deceleration and reacceleration upon developmental resumption are unclear. We propose that amino acids of maternal origin drive the embryonic developmental pace. A pronounced change in the abundance of uterine fluid mTORC1-activating amino acids coincided with an increase in embryonic mTORC1 activity prior to the resumption of development. Concurrently, genes related to the glycolytic and phosphate pentose pathway, the TCA cycle, and one carbon metabolism were up-regulated. Furthermore, the uterine luminal epithelial transcriptome indicated increased estradiol-17β signaling, which likely regulates the endometrial secretions adapting to the embryonic needs. While mTORC1 was predicted to be inactive during diapause, the residual embryonic mTORC2 activity may indicate its involvement in maintaining the low yet continuous proliferation rate during diapause. Collectively, we emphasize the role of nutrient signaling in preimplantation embryo development. We propose selective mTORC1 inhibition via uterine catecholestrogens and let-7 as a mechanism regulating slow stem cell cycle progression.

Addition of Olive Leaf Extract to a Mixture of Algae and Extra Virgin Olive Oils Decreases Fatty Acid Oxidation and Synergically Attenuates Age-Induced Hypertension, Sarcopenia and Insulin Resistance in Rats

Olive-derived products, such as virgin olive oil (EVOO) and/or olive leaf extracts (OLE), exert anti-inflammatory, insulin-sensitizing and antihypertensive properties and may be useful for stabilizing omega 3 fatty acids (n-3 PUFA) due to their high content in antioxidant compounds. In this study, the addition of OLE 4:0.15 (w/w) to a mixture of algae oil (AO) rich in n-3 PUFA and EVOO (25:75, w/w) prevents peroxides formation after 12 months of storage at 30 °C. Furthermore, the treatment with the oil mixture (2.5 mL/Kg) and OLE (100 mg/Kg) to 24 month old Wistar rats for 21 days improved the lipid profile, increased the HOMA-IR and decreased the serum levels of miRNAs 21 and 146a. Treatment with this new nutraceutical also prevented age-induced insulin resistance in the liver, gastrocnemius and visceral adipose tissue by decreasing the mRNA levels of inflammatory and oxidative stress markers. Oil mixture + OLE also attenuated the age-induced alterations in vascular function and prevented muscle loss by decreasing the expression of sarcopenia-related markers. In conclusion, treatment with a new nutraceutical based on a mixture of EVOO, AO and OLE is a useful strategy for improving the stability of n-3 PUFA in the final product and to attenuate the cardiometabolic and muscular disorders associated with aging.

A Mixture of Algae and Extra Virgin Olive Oils Attenuates the Cardiometabolic Alterations Associated with Aging in Male Wistar Rats

Aging is one of the major risk factors for suffering cardiovascular and metabolic diseases. Due to the increase in life expectancy, there is a strong interest in the search for anti-aging strategies to treat and prevent these aging-induced disorders. Both omega 3 polyunsaturated fatty acids (ω-3 PUFA) and extra virgin olive oil (EVOO) exert numerous metabolic and cardiovascular benefits in the elderly. In addition, EVOO constitutes an interesting ingredient to stabilize ω-3 PUFA and decrease their oxidation process due to its high content in antioxidant compounds. ω-3 PUFA are commonly obtained from fish. However, more ecological and sustainable sources, such as algae oil (AO) can also be used. In this study, we aimed to study the possible beneficial effect of an oil mixture composed by EVOO (75%) and AO (25%) rich in ω-3 PUFA (35% docosahexaenoic acid (DHA) and 20% eicosapentaenoic acid (EPA)) on the cardiometabolic alterations associated with aging. For this purpose; young (three months old) and old (24 months old) male Wistar rats were treated with vehicle or with the oil mixture (2.5 mL/kg) for 21 days. Treatment with the oil mixture prevented the aging-induced increase in the serum levels of saturated fatty acids (SFA) and the aging-induced decrease in the serum concentrations of mono-unsaturated fatty acids (MUFA). Old treated rats showed increased serum concentrations of EPA and DHA and decreased HOMA-IR index and circulating levels of total cholesterol, insulin and IL-6. Treatment with the oil mixture increased the mRNA levels of antioxidant and insulin sensitivity-related enzymes, as well as reduced the gene expression of pro-inflammatory markers in the liver and in cardiac and aortic tissues. In addition, the treatment also prevented the aging-induced endothelial dysfunction and vascular insulin resistance through activation of the PI3K/Akt pathway. Moreover, aortic rings from old rats treated with the oil mixture showed a decreased response to the vasoconstrictor AngII. In conclusion, treatment with a mixture of EVOO and AO improves the lipid profile, insulin sensitivity and vascular function in aged rats and decreases aging-induced inflammation and oxidative stress in the liver, and in the cardiovascular system. Thus, it could be an interesting strategy to deal with cardiometabolic alterations associated with aging.

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.

Metabolic Changes of Maternal Uterine Fluid, Uterus, and Plasma during the Peri-implantation Period of Early Pregnancy in Mice

Embryo implantation is a complex process which involves biochemical and physiological interactions between an implantation-competent blastocyst and a receptive uterus. However, the exact biochemical changes of uterine fluid, uterus, and plasma during peri-implantation remain unclear. This study aims to characterize the biochemical and metabolic changes that occur during the peri-implantation period of early pregnancy, using mice as an animal model. Gas chromatography-mass spectrometry was used to analyze the metabolite profiles of the uterus, uterine fluid, and maternal plasma at pre-implantation and implantation. The multivariate analyses, ANOVA and Tukey's HSD test, were applied to detect significant changes in metabolites and metabolic pathways. The metabolic networks were reconstructed in silico based on the identified metabolites and KEGG metabolic framework. Between pre-implantation day 1 and day 4, dramatic metabolic changes were observed in the uterine fluid that could be important for blastocyst development and protection against the harsh uterine environment. Palmitoleic acid, fumaric acid, and glutaric acid changed levels at day 4 in the uterus, suggesting that they may be associated with endometrial receptivity. Both the uterus and maternal plasma showed profound changes in cellular metabolism at the early implantation period, including upregulation of branched-chain amino acids and intermediates of one-carbon metabolism, an upregulation of glyoxylate and dicarboxylate metabolism, and downregulation of aerobic respiration; all of which could be involved in the regulation of the maternal-fetal interface, alternative nutrient utilization, and energy preservation for implantation as well as later placentation and fetal development to ensure successful embryo implantation.

Proteomic analysis of sheep uterus reveals its role in prolificacy

Small Tail Han sheep have attracted attention for their high fecundity and year-round estrus. However, the molecular mechanisms of this fecundity are unknown. Polymorphism of the FecB gene has been shown to be associated with the ovulation rate and litter size in sheep. In this study, we used tandem mass tag quantitative proteomic techniques to identify the differentially abundant proteins in polytocous and monotocous Small Tail Han sheep (FecB++) uterine tissues in the follicular and luteal phases. In total, 41 and 43 differentially abundant proteins were identified in the follicular and luteal phases, respectively. Correlation analysis between the transcriptome and proteome revealed a positive correlation at the two omics levels of prolificacy. GO and KEGG pathway analyses indicated that the mRNAs and proteins upregulated in the polytocous group relative to the monotocous group are involved in sphingolipid metabolism and amino acid metabolism, and may be important in maintaining uterine functions and increasing the embryo survival rate during the estrus cycle of polytocous sheep. In conclusion, our work provides a prospective understanding of the molecular mechanism underlying the high prolificacy of Small Tail Han sheep. SIGNIFICANCE: Fecundity critically affects the profitability of sheep production, but the genetic mechanism of high-prolificacy is still unclear in sheep. We identified potential signaling pathways and differentially abundant proteins associated with reproductive performance through a combination of sheep uterus tissues proteome and transcriptome analyses. These findings will facilitate a better revealing the mechanism and provide possible targets for molecular design breeding for the formation of polytocous traits in sheep.

In vitro supplementation with unsaturated fatty acids improves boar sperm viability after storage at 6 °C

Liquid preservation of the cold-sensitive boar sperm at a lesser temperature than the standard 17 °C would reduce bacterial growth and minimize the use of antibiotics. There was assessment, therefore, of the capacity of individual fatty acids bound to fatty acid free BSA to improve sperm survival at 6 °C because oxidative stress and lipid degradation are prominent detrimental factors. Different effects of the fatty acids were observed. Supplementation with naturally occurring fatty acids (linolenic, linoleic, oleic, palmitoleic acid), which may become metabolically incorporated into sperm lipids, increased the number of motile and progressively motile sperm after 2 days of storage during a thermo-resistance test (5 h at 38 °C) to that of control samples preserved at 17 °C in pure Beltsville Thawing Solution. With the exception of linolenic acid, all naturally occurring fatty acids enhanced the number of sperm with active mitochondria after 3 days of storage. Palmitoleic acid was the most effective supplement with effects already present when sperm were re-warmed for 30 min after 2 and 7 days of storage. The non-endogenous, non-integrated timnodonic acid (20:5) had no effect on sperm variables. Because the application of individual fatty acids attached to BSA had differing effects in preserving boar sperm at 6 °C, the use of combinations of fatty acids could be more efficacious than with use of natural lipid supplements for low temperature preservation of sperm.