Docosahexaenoic acid (DHA) effects on proliferation and steroidogenesis of bovine granulosa cells

Different Lengths of Diet Supplementation with 10% Flaxseed Alter the Hormonal Profile and the Follicular Fluid Fatty Acid Content of Fattening Gilts

The effect of 10% dietary flaxseed fed for 3 and 6 weeks on serum hormone levels of fattening gilts, the fatty acid (FA) follicular fluid (FF) composition of small and large antral follicles, and the steroidogenesis and IGF-I secretion by isolated small antral follicles and their response to regulatory hormones (LH, FSH, IGF-I) was studied using immunoassay and gas chromatography analyses. Both supplemental periods increased levels of P4 and IGF-I in blood serum. A shorter period inhibited steroidogenesis (P4, T, E2) and IGF-I secretion by small antral follicles, which was associated with decreased levels of monounsaturated FAs (MUFA) and preferred n-6 polyunsaturated FA (PUFA) metabolism. A longer period stimulated hormone secretion at elevated levels of saturated FAs (SFA) at the expense of MUFAs and PUFAs preferring the n-3 PUFA metabolism. Out of ovarian regulators, only LH and IGF-I were able to alter the secretion of steroids and IGF-I by small follicles of fattening pigs fed a basal diet. The effect of flaxseed on the secretion of follicular hormones after both supplemental periods was altered by all regulatory hormones in a dose-dependent manner. The level of SFAs and PUFAs in FF of large follicles increased with the length of flaxseed feeding, suggesting the suppression of ovulation.

Endogenous biosynthesis of docosahexaenoic acid (DHA) regulates fish oocyte maturation by promoting pregnenolone production

Omega-3 polyunsaturated fatty acids (n-3 PUFAs), particularly docosahexaenoic acid (22:6n-3, DHA), play crucial roles in the reproductive health of vertebrates, including humans. Nevertheless, the underlying mechanism related to this phenomenon remains largely unknown. In this study, we employed two zebrafish genetic models, i.e., elovl2 -/- mutant as an endogenous DHA-deficient model and fat1 (omega-3 desaturase encoding gene) transgenic zebrafish as an endogenous DHA-rich model, to investigate the effects of DHA on oocyte maturation and quality. Results show that the elovl2 -/- mutants had much lower fecundity and poorer oocyte quality than the wild-type controls, while the fat1 zebrafish had higher fecundity and better oocyte quality than wild-type controls. DHA deficiency in elovl2 -/- embryos led to defects in egg activation, poor microtubule stability, and reduced pregnenolone levels. Further study revealed that DHA promoted pregnenolone synthesis by enhancing transcription of cyp11a1, which encodes the cholesterol side-chain cleavage enzyme, thereby stabilizing microtubule assembly during oogenesis. In turn, the hypothalamic-pituitary-gonadal axis was enhanced by DHA. In conclusion, using two unique genetic models, our findings demonstrate that endogenously synthesized DHA promotes oocyte maturation and quality by promoting pregnenolone production via transcriptional regulation of cyp11a1.

Integrated transcriptomic and metabolomic investigation of the genes and metabolites involved in swine follicular cyst formation

Follicular cysts are a common reproductive disorder in mammals that is usually caused by stress. However, the pathogenesis of follicular cysts in sows remains unclear. To provide new insights into the mechanisms of follicular cyst formation in pigs, we conducted a combined transcriptomic and metabolomic analysis on theca interna and mural granulosa cells of follicular cysts and mature follicles. We identified 2,533 up-regulated and 1,355 down-regulated genes in follicular cysts, compared with mature follicles. These differentially expressed genes were mainly found in signaling pathways related to tumor formation and cortisol synthesis and secretion as shown by Ingenuity Pathway Analysis, which predicted 4,362 upstream regulatory factors. The combined gene expression and pathway analysis identified the following genes as potential biomarkers for porcine follicular cysts: cytochrome P450 family 2 subfamily C polypeptide 18, L-lactate dehydrogenase, carbamoyl-phosphate synthase, fibroblast growth factor 7, integrin binding sialoprotein, interleukin 23 receptor, prolactin receptor, epiregulin, interleukin 1 receptor type II, arginine vasopressin receptor 1A, fibroblast growth factor 10, claudin 7, G Protein Subunit Gamma 3, cholecystokinin B receptor and cytosolic phospholipase A2. Metabolomics analysis found significant differences in 87 metabolites, which were enriched in unsaturated fatty acid biosynthesis, and sphingolipid signaling pathways. These results provide valuable information on the molecular mechanisms of follicular cyst formation, which may facilitate the development of new therapeutics to prevent and treat follicular cysts.

Gene expression of free fatty acids-sensing G protein-coupled receptors in beef cattle

Many physiological functions are regulated by free fatty acids (FFA). Recently, the discovery of FFA-specific G protein-coupled receptors (FFARs) has added to the complexity of their actions at the cellular level. The study of FFAR in cattle is still in its earliest stages focusing mainly on dairy cows. In this study, we set out to map the expression of genes encoding FFARs in 6 tissues of beef cattle. We also investigated the potential effect of dietary forage nature on FFAR gene expression. To this end, 16 purebred Charolais bulls were fed a grass silage ration or a maize silage ration (n = 8/group) with a forage/concentrate ratio close to 60:40 for 196 d. The animals were then slaughtered at 485 ± 42 d and liver, spleen, ileum, rectum, perirenal adipose tissue (PRAT), and Longissimus Thoracis muscle were collected. FFAR gene expression was determined by real-time quantitative PCR. Our results showed that of the five FFARs investigated, FFAR1, FFAR2, FFAR3, and GPR84 are expressed (Ct < 30) in all six tissues, whereas FFAR4 was only expressed (Ct < 30) in PRAT, ileum, and rectum. In addition, our results showed that the nature of the forage, i.e., grass silage or maize silage, had no effect on the relative abundance of FFAR in any of the tissues studied (P value > 0.05). Taken together, these results open new perspectives for studying the physiological role of these receptors in beef cattle, particularly in nutrient partitioning during growth.

Expression characteristics of Hsd3b7 in the gonads of Paralichthys olivaceus

Steroidogenesis is an important biological process for gonadal differentiation and development. In mammals, 3β-hydroxysteroid dehydrogenase 7 (HSD3B7) could convert 3β-hydroxy of 7α-hydroxycholesterol into a ketone and form 7α-hydroxy-4-cholesten-3-one, which may affect steroidogenesis. However, in fish, the study of Hsd3b7 is still lacking. In this study, Hsd3b7 was identified in the olive flounder Paralichthys olivaceus, an important mariculture fish. According to bioinformatics analysis, Hsd3b7 belongs to a Rossmann-fold NAD(P)(+)-binding protein and can interact in a predictable manner with Hsd17b2, -3, and - 4, which play a role in steroidogenesis. In the adult flounder, Hsd3b7 was expressed in various tissues, at particularly high level in male muscle. The expression levels of Hsd3b7 at gonadal development stages I-V initially increased and then decreased, with an inflection point in the ovary at stage III and in the testis at stage IV. At stage III, the expression level of Hsd3b7 was significantly higher in the ovary than in the testis (P < 0.01). The results of in situ hybridization (ISH) revealed that it was mainly expressed in oocytes of phases I-IV or around oocytes of phases IV-V in the ovaries and around spermatid lobules at stages IV-V in the testes. Three regulatory sites of SRY-box transcription factor 9 (Sox9), a transcription factor involved in steroidogenesis and gonadal differentiation, were predicted in the promoter of Hsd3b7. After intraperitoneal injection with the recombination flounder Sox9a, the expression of Hsd3b7 was significantly up-regulated (P < 0.01). During the flounder gonadal differentiation, 17β-estradiol (E2, 5 μg/g feed) and 17α-methyltestosterone (T, 5 μg/g feed) were used to obtain the phenotypic female or male flounder, and the results showed that in the E2 group, Hsd3b7 expression was highest at 2 cm TL, the primordial gonad stage, which was significantly higher than that at 12 cm TL (P < 0.05). In the T group, Hsd3b7 expression level was also highest at 2 cm TL and significantly higher than at 10 and 12 cm TL (P < 0.05). Moreover, Hsd3b7 was detected to be localized mainly around oogonia and spermatogonia during the differentiated gonads with ISH. These findings first introduce the expression characteristics of Hsd3b7 and the effect of Sox9a on its expression, which contribute to our understanding of the function of Hsd3b7 in fish gonads.

Protective effects of MNQ against Lipopolysaccharide-induced inflammatory damage in bovine ovarian follicular granulosa cells in Vitro

Inflammation of the reproductive tract in dairy cows lead to functional disorders of follicular granulosa cells (GCs) in mammalian ovaries resulting in infertility and serious losses to the livestock industry. Lipopolysaccharide (LPS) can induce an inflammatory response in follicular granulosa cells in vitro. The aim of this study was to investigate the cellular regulatory mechanism of MNQ (2-methoxy-1,4-naphthoquinone) on eliminating the inflammatory response and restoring normal functions for bovine ovarian follicular GCs cultured in vitro exposed to LPS. The cytotoxicity of MNQ and LPS on GCs were detected by MTT method to determine the safe concentration. The relative expression of inflammatory factors and steroid synthesis-related genes were detected by qRT-PCR. The concentration of steroid hormones in the culture broth were detected by ELISA. Differential gene expressions were analyzed by RNA-seq. There were no toxic effects on GCs at MNQ and LPS concentrations of less than 3 µM and 10 µg/mL, respectively and treated in 12 h. The relative expressions of IL-6, IL-1β and TNF-α were significantly higher in the LPS group compared with the CK group when GCs cultured in vitro were treated with the above concentrations and times (P < 0.05), but significantly lower in the MNQ+LPS group compared with the LPS group (P < 0.05). The levels of E₂ and P₄ in the culture solution were significantly reduced in the LPS group compared to the CK group (P < 0.05), and restored in the MNQ+LPS group. The relative expressions of CYP19A1, CYP11A1, 3β-HSD, and STAR were significantly decreased in the LPS group compared with the CK group (P < 0.05), while the MNQ+LPS group also recovered to some extent. There were 407 differential genes shared by LPS vs CK and MNQ+LPS vs LPS by RNA-seq analysis, which were mainly enriched in steroid biosynthesis and TNF signaling pathway. We screened 10 genes for analysis and found consistent results for RNA-seq and qRT-PCR. In this study, we confirmed the protective effect of MNQ, an extract from Impatiens balsamina L, on LPS-induced inflammatory responses in bovine follicular granulosa cells in vitro as well as functional damage, and acted through steroid biosynthesis and TNF signaling pathways.

Role of functional fatty acids in modulation of reproductive potential in livestock

Fatty acids are not only widely known as energy sources, but also play important roles in many metabolic pathways. The significance of fatty acids in modulating the reproductive potential of livestock has received greater recognition in recent years. Functional fatty acids and their metabolites improve follicular development, oocyte maturation and embryo development, as well as endometrial receptivity and placental vascular development, through enhancing energy supply and precursors for the synthesis of their productive hormones, such as steroid hormones and prostaglandins. However, many studies are focused on the impacts of individual functional fatty acids in the reproductive cycle, lacking studies involved in deeper mechanisms and optimal fatty acid requirements for specific physiological stages. Therefore, an overall consideration of the combination and synergy of functional fatty acids and the establishment of optimal fatty acid requirement for specific stages is needed to improve reproductive potential in livestock.

Effects of polyunsaturated fatty acid supplementation on plasma and follicular fluid resolvin D1 concentration and mRNA abundance in granulosa cells in ewes

The aim of this experiment was to evaluate the effect of increasing dietary omega-3 (n-3) polyunsaturated fatty acid (PUFA) supplementation on plasma and follicular fluid resolvin D1 (RvD1) concentration and the mRNA expression of genes related to RvD1 production, inflammatory response, oxidative stress, hormone receptors and production, and free fatty acid receptors in the granulosa cells of ewes. Dorset × Hampshire ewes (n = 24) aged 2 to 4 yr and with an initial body weight (BW) of 84.08 ± 13.18 kg were blocked by body condition score (BCS) and BW, and randomly assigned to 12 pens. Each pen within each block was randomly assigned to one of three treatments: 1) diet without fatty acid supplementation (control), 2) diet with 0.5% n-3 PUFA supplementation (PUFA0.5), and 3) diet with 1% n-3 PUFA supplementation (PUFA1). BW, BCS, and blood samples were obtained on day 1 and every 21 d for 3 mo. Ewes were then synchronized, superstimulated, and ovariectomized. Antral follicles were aspirated to evaluate RvD1 concentration in follicular fluid, and granulosa cells were used to determine mRNA abundance. Data were analyzed as a randomized complete block design using a mixed model (MIXED or GLIMMIX with log as a link function when data presented a nonnormal distribution). A polynomial effect of treatments was used to analyze RvD1 concentration and mRNA expression when there was no interaction. In addition, the correlation between plasma and follicular fluid RvD1 concentration was evaluated. We found no differences in BW (P = 0.28) and BCS (P = 0.29) between treatments. The concentration of RvD1 in plasma and follicular fluid linearly increased (P = 0.03) and tended to increase (P = 0.06) concomitantly to increasing PUFA supplementation. Plasma and follicular fluid RvD1 concentrations were positively correlated (r = 0.61; P < 0.01). The abundance of GPX1 and GPR32 mRNA tended to increase linearly with increasing PUFA supplementation (P = 0.06). In addition, PUFA supplementation linearly decreased and tended to decrease IL-1β and COX-2 mRNA abundance (P = 0.01 and P = 0.06, respectively). In conclusion, the correlation between plasma and follicular fluid RvD1 concentration indicates a relationship between both compartments. Also, the decrease of IL-1β and the increase of GPX1 mRNA abundance after PUFA supplementation could have beneficial effects on follicle development.

Docosahexaenoic Acid Counteracts the Hypoxic-Induced Inflammatory and Metabolic Alterations in 3T3-L1 Adipocytes

Background: Hypoxia is caused by the excessive expansion of the white adipose tissue (AT) and is associated with obesity-related conditions such as insulin resistance, inflammation, and oxidative stress. Docosahexaenoic acid (DHA) is an omega-3 fatty acid reported to have beneficial health effects. However, the effects of DHA in AT against hypoxia-induced immune-metabolic perturbations in adipocytes exposed to low O₂ tension are not well known. Consequently, this study aimed to evaluate the impact of DHA on markers of inflammation, metabolism, apoptosis, and oxidative stress in 3T3-L1 cell adipocytes exposed to low O₂ tension (1% O₂) induced hypoxia. Methods: The apoptosis and reactive oxygen species (ROS) rates were evaluated. Metabolic parameters such as lactate, FFA, glycerol release, glucose uptake, and ATP content were assessed by a fluorometer. The expression of HIF-1, GLUT1 and the secretion of adipocytokines such as leptin, adiponectin, and pro-inflammatory markers was evaluated. Results: DHA-treated hypoxic cells showed significantly decreased basal free fatty acid release, lactate production, and enhanced glucose consumption. In addition, DHA-treatment of hypoxic cells caused a significant reduction in the apoptosis rate and ROS production with decreased lipid peroxidation. Moreover, DHA-treatment of hypoxic cells caused a decreased secretion of pro-inflammatory markers (IL-6, MCP-1) and leptin and increased adiponectin secretion compared with hypoxic cells. Furthermore, DHA-treatment of hypoxic cells caused significant reductions in the expression of genes related to hypoxia (HIF-1, HIF-2), anaerobic metabolism (GLUT1 and Ldha), ATP production (ANT2), and fat metabolism (FASN and PPARY). Conclusion: This study suggests that DHA can exert potential anti-obesity effects by reducing the secretion of inflammatory adipokines, oxidative stress, lipolysis, and apoptosis.

Association between polyunsaturated fatty acid intake and infertility among American women aged 20-44 years

Background

Infertility is a nationwide public health priority in the U.S. However, few studies have investigated the effects of dietary intake of polyunsaturated fatty acids (PUFAs) on female infertility. This study explored the association between PUFA intake and risk of infertility.

Methods

A total of 1,785 women aged 20-44 years from three National Health and Nutrition Examination Survey cycles (2013-2018) were included in this cross-sectional study. The intake of PUFAs was obtained from a 24-h dietary interview on two separate days with a 3-10-day interval, and nutrient residue models were used. Fertility status was assessed by positive response to two relative questions via a questionnaire. Logistic regression models were used and some covariates were adjusted.

Results

Among all the participants, 340 (19.05%) women suffered from infertility. The intake of docosahexaenoic acid (DHA) (OR = 0.998, 95% CI 0.998, 0.009) was slightly related to the risk of infertility. In contrast, women with higher α-linolenic acid (ALA) (OR = 1.416, 95% CI 1.138, 1.763) and linoleic acid (LA) intake (OR = 1.020, 95% CI 1.002, 1.038) presented with a relatively higher risk of primary infertility. Furthermore, in 20-34-year-old women, higher omega-6/omega-3 was significant associated with the risk of infertility (OR = 1.002, 95%CI 1.000, 1.005).

Conclusions

Our results suggest that PUFA intake is only slightly associated with infertility. The higher the DHA intake, the lower the risk of infertility regardless of age. In women with primary infertility, ALA and LA has negative effect.

GC-MS metabolomics reveals dysregulated lipid metabolic pathways and metabolites in diabetic testicular toxicity: Therapeutic potentials of raffia palm (Raphia hookeri G. Mann & H. Wendl) wine

ETHNOPHARMACOLOGICAL RELEVANCE

Raffia palm (Raphia hookeri G. Mann & H. Wendl) wine (RPW) is a natural beverage obtained from the R. hookeri consumed for refreshment and medicinal purposes. For medicinal purposes, it is used singly or as macerating agent for other medicinal plants for the treatment of several diseases.

AIM

This study investigates the effect of Raffia palm wine on dysregulated lipid metabolic pathways in testicular tissues of type 2 diabetic (T2D) rats.

METHODS

Raffia palm wine (150 and 300 mg/kg bodyweight) was administered to two T2D groups respectively, another T2D group was not administered treatment and served as negative control, while metformin served as the standard drug. After 6 weeks of treatment, the rats were sacrificed, and the testes collected. After weighing, the organs were homogenized in 20% methanol/ethanol and centrifuged at 20,000 g to extract the lipid metabolites.

RESULTS

GC-MS analysis of the supernatants revealed an alteration of the metabolites on induction of T2D, with concomitant generation of 10 metabolites. Raffia palm wine inhibited the T2D-generated metabolites while replenishing cholesterol and squalene levels, with concomitant generation of 7 and 8 metabolites for low and high dose treatment respectively. Pathway enrichment analysis of the metabolites revealed a decreased level of steroid biosynthesis and increased level of fatty acid biosynthesis. Raffia palm wine inactivated glycerolipid, fatty acid, and arachidonic acid metabolisms, fatty acid biosynthesis and fatty acid elongation in mitochondria pathways, and activated pathways for plasmalogen synthesis, mitochondrial beta-oxidation of long chain saturated fatty acids.

CONCLUSION

The replenishment and generation of these metabolites and additional ones as well as activation of pathways involved in energy generation, phospholipids, antioxidant activity, steroidogenesis and spermatogenesis suggest a therapeutic effect of Raffia palm wine against hyperglycemic-induced testicular dysfunction.

Effect of docosahexaenoic acid plus insulin on atherosclerotic human endothelial cells

Background

Atherosclerosis is touted as one of the most critical consequences of diabetes mellitus indicated by local inflammation of endothelial cells. The Effect of Omega 3 fatty acids, mainly docosahexaenoic acid (DHA), has been investigated in cells after exposure to high doses of lipids. The current experiment aimed to address the modulatory effects of docosahexaenoic acid and insulin in palmitic-treated human endothelial cells.

Methods

Human umbilical vein endothelial cells were treated with 1 mM palmitic acid, 50 μM insulin, 50 μM docosahexaenoic acid, and their combination for 48 h. Cell survival rate and apoptosis were measured using MTT and flow cytometry assays. The Griess assay detected NO levels. Protein levels of TNF-α, IL-6, and NF-κB were studied using ELISA and immunofluorescence imaging. The expression of genes participating in atherosclerosis was monitored using PCR array analysis.

Results

Oil Red O staining showed the inhibitory effect of DHA and insulin to reduce the intracellular accumulation of palmitic acid. Both DHA and Insulin blunted palmitic acid detrimental effects on HUVECs indicated by an increased survival rate (p < 0.05). The percent of apoptotic cells was decreased in palmitic-treated cells received insulin and DHA compared to palmitic-treated group (p < 0.05). Based on our data, DHA and Insulin diminished the production of all inflammatory cytokines, TNF-α, IL-6, and NF-κB, in palmitic-treated cells (p < 0.05). Similar to these data, NO production was also decreased in all groups treated with insulin and DHA compared to the palmitic-treated cells (p < 0.05). PCR array analysis revealed the modulatory effect of DHA and insulin on the expression of atherosclerosis-related genes pre-treated with palmitic acid compared to the control group (p < 0.05).

Conclusion

DHA and Insulin could alter the dynamic growth and dysfunctional activity of human endothelial cells after treatment with palmitic acid. Taken together, Omega 3 fatty acids, along with insulin, could dictate specific cell behavior in endothelial cells in vitro.

Stimulation of follicle growth and development during estrus in Ettawa Grade does fed a flushing supplement of different polyunsaturated fatty acids

Background and Aim

Flushing with the manipulation of fatty acids, particularly polyunsaturated fatty acids, like linoleic and α-linolenic acids in the ration, is a strategy to raise the nutritional status of the female mammals to improve ovarian function and follicle development. This study was designed to investigate the effectiveness of flushing supplementation with different types of polyunsaturated and saturated fatty acids in stimulating follicle growth and development during estrus in Ettawa Grade does with a low initial body condition score (BCS ≤2).

Materials and Methods

Eighteen Ettawa Grade does in the second parity, with an average body weight of 32.11±2.19 kg, were divided into three groups according to the fatty acid supplemented to their ration: (i) About 2.8% lauric acid flushing (group); (ii) 2.8% linoleic acid flushing (LA group); and (iii) 2.8% α-linolenic acid flushing (ALA group). The ration was formulated to be isocaloric (total digestible nutrient = 77%) and isonitrogenous (crude protein = 15%). The experiment was conducted for 35 days; that is, 14 days for acclimatization and synchronization of the estrous cycle and 21 days for fatty acid flushing until the appearance of the next estrus. A completely randomized design was applied.

Results

According to the results, none of the different fatty acids in the ration affected the nutrient intakes, BCSs, average daily gains, and plasma glucose, cholesterol, and progesterone concentrations of the three groups of does. However, the BCSs (by 0.8-0.9) and the plasma cholesterol concentrations were higher after fatty acid flushing for 21 days than before the flushing period. The ALA group had the highest number of large-sized preovulatory follicles, whereas the LAURIC group had the highest plasma estradiol concentration during estrus. All three groups had similar plasma progesterone concentrations during estrus after fatty acid flushing.

Conclusion

Flushing supplementation with 2.8% ALA from flaxseed oil gave the best results in terms of stimulating the highest number of large-sized preovulatory follicles in Ettawa Grade does.

Effects of maternal dietary omega-3 polyunsaturated fatty acids and methionine during late gestation on fetal growth, DNA methylation, and mRNA relative expression of genes associated with the inflammatory response, lipid metabolism and DNA methylation in placenta and offspring's liver in sheep

BACKGROUND

Omega-3 PUFA or methionine (Met) supply during gestation alters offspring physiology. However, the effect of both nutrients on fetal development has not been explored. Our objective was to determine the effects of supplementation of these two nutrients during late gestation on fetal growth, DNA methylation, and mRNA expression of genes associated with the inflammatory response, and DNA methylation. Ewes (n = 5/treatment) were fed from day 100 to 145 of gestation one of the following treatments: 1) basal diet (NS) without fatty acids (FS) or methionine (MS) supplementation; 2) FS (10 g/kg Ca salts, source omega-3 PUFA); 3) MS (1 g/kg rumen protected methionine); and 4) FS and MS (FS-MS). On day 145, ewes were euthanized, and data from dams and fetus was recorded. Placenta (cotyledon), fetal liver, and blood samples were collected.

RESULTS

A treatments interaction on fetal liver weight, ewe body weight and body condition score (BCS) was observed; FS-MS were heavier (P <  0.01) than FS and MS, and FS-MS ewes had a better (P = 0.02) BCS than NS. Methionine increased (P = 0.03) ewe plasma glucose concentration. Fetal liver global DNA methylation increased (P <  0.01) in FS and MS. Dietary treatments modify the mRNA relative expression on some of the genes evaluated. In the fetal liver, FS increased (P = 0.04) the mRNA relative expression of arachidonate-5-lipoxygenase-activating-protein and tended to decrease (P = 0.06) methionine-adenosyltransferase-1A. Moreover, MS decreased (P = 0.04) DNA-methyltransferase-1 and tended to decrease (P = 0.08) free-fatty-acid-receptor-1 mRNA relative expression. Furthermore, FS-MS decreased mRNA relative expression of tumor-necrosis-factor-alpha (P = 0.05), peroxisome-proliferator-activated-receptor-delta (P = 0.03) and gamma (P = 0.04), tended to decrease (P ≤ 0.09) interleukin-6, fatty-acid-transport-protein-1, and delta-5-desaturase, and increased adenosylhomocysteinase (P = 0.04) mRNA relative expression. In cotyledon, FS tended to decrease fatty acid binding protein 4 (P = 0.09) mRNA relative expression.

CONCLUSION

Omega-3 PUFA and Met supplementation improves dam's performance in late gestation, which was positively correlated with an increase in offspring's liver development. Moreover, FS-MS decreased mRNA relative expression of proinflammatory cytokines, and lipogenic genes, and increased the expression on an enzyme that has an important role in methylation.

Advances in fatty acids nutrition in dairy cows: from gut to cells and effects on performance

High producing dairy cows generally receive in the diet up to 5-6% of fat. This is a relatively low amount of fat in the diet compared to diets in monogastrics; however, dietary fat is important for dairy cows as demonstrated by the benefits of supplementing cows with various fatty acids (FA). Several FA are highly bioactive, especially by affecting the transcriptome; thus, they have nutrigenomic effects. In the present review, we provide an up-to-date understanding of the utilization of FA by dairy cows including the main processes affecting FA in the rumen, molecular aspects of the absorption of FA by the gut, synthesis, secretion, and utilization of chylomicrons; uptake and metabolism of FA by peripheral tissues, with a main emphasis on the liver, and main transcription factors regulated by FA. Most of the advances in FA utilization by rumen microorganisms and intestinal absorption of FA in dairy cows were made before the end of the last century with little information generated afterwards. However, large advances on the molecular aspects of intestinal absorption and cellular uptake of FA were made on monogastric species in the last 20 years. We provide a model of FA utilization in dairy cows by using information generated in monogastrics and enriching it with data produced in dairy cows. We also reviewed the latest studies on the effects of dietary FA on milk yield, milk fatty acid composition, reproduction, and health in dairy cows. The reviewed data revealed a complex picture with the FA being active in each step of the way, starting from influencing rumen microbiota, regulating intestinal absorption, and affecting cellular uptake and utilization by peripheral tissues, making prediction on in vivo nutrigenomic effects of FA challenging.

Effects of dietary supplementation with algae, sunflower oil or soybean oil on folliculogenesis in the rabbit ovary during sexual maturation

This study aimed to examine the effects of algae (rich in omega-3 fatty acids), sunflower oil (rich in omega-6 fatty acids) and soybean oil (rich in omega-6 fatty acids) on the entire folliculogenesis in juvenile and sexually mature rabbits. After weaning, rabbits were randomly divided into four experimental groups of 14 animals each. Control animals received non-supplemented pellets, while in the other groups, the pellets contained 1% marine algae, 3% sunflower oil or 3% soybean oil. Animals from each group were slaughtered at 12 weeks of age (n = 7 per group) or at 18 weeks of age (n = 7 per group). The ovaries were harvested and fixed for hematoxylin-eosin staining, immunohistochemical localization of PCNA and TUNEL assay. Algae-enriched diet markedly decreased the number of primordial and primary follicles, while addition of sunflower oil reduced the number of primary follicles in 12-week-old rabbits. The number of antral follicles was higher following algae supplementation, but lower after addition of soybean oil in that age group. Proliferating index was decreased following supplementation with algae and soybean oil in juvenile rabbits, whereas it was increased after addition of algae and decreased following vegetable oils in mature ones. Dietary PUFAs did not impact apoptosis in the rabbit ovary of both age groups. The obtained results suggest that PUFA-enriched diet regulate either early folliculogenesis or antral follicle development in rabbits that might influence reproductive performance as a consequence. It appears that observed effects are attributed to sexual maturity.

Eicosapentaenoic and docosahexaenoic acid supplementation during early gestation modified relative abundance on placenta and fetal liver tissue mRNA and concentration pattern of fatty acids in fetal liver and fetal central nervous system of sheep

In sheep, polyunsaturated fatty acid (PUFA) supplementations in late gestation increases the growth of offspring; however, there is a lack of evidence on the effect of PUFA supplementation during early gestation. Thus, the objective of this study was to evaluate the effect of dietary supplementation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in early gestation pregnant ewes on fatty acid concentration of fetal liver (FL) and fetal central nervous system (FCNS), and relative abundance of the mRNA for genes associated with transport and metabolism of fatty acids in FL and placenta. A total of 12 ewes, block for stage of gestation were fed a diet containing 1.6% (dry matter basis) monounsaturated fatty acids (MUFA) or EPA+DHA during the first 45 days of gestation. A cesarean section was conducted on day 45 of gestation to collect placenta (caruncle and cotyledon), FL, and FCNS. Relative abundance of mRNA in FL and FCNS and fatty acid concentration were analyzed using a 2x2 factorial arrangement of treatments considering fatty acid supplementation and tissue as the main factors. Concentrations of C18:1 isomers increase (P < 0.05) in FL and FCNS with MUFA supplementation; the FL and FCNS had a greater concentration of C20:3(n-6), C20:3(n-3), C22:1, C22:5 and C22:6 (P < 0.05) with EPA+DHA supplementation. In FL, the relative abundance of LPL mRNA was greater (P = 0.02) as a result of MUFA supplementation. In placenta, there was a FA x tissue interaction for relative abundance of DNMT3b and FFAR-4 mRNA (P < 0.05). Fetus from MUFA-supplemented dams had a greater relative abundance of FABP-4 mRNA (P < 0.05). Results indicate supplementation with EPA+DHA during early gestation increases the total EPA and DHA in FL. For the placenta, EPA+DHA supplementation led to an increase in the relative abundance of lipid mRNA for transport genes.

Bisphenol S Impaired Human Granulosa Cell Steroidogenesis in Vitro

Bisphenol S (BPS) is a structural analog of the endocrine disruptor bisphenol A (BPA); it is the main BPA replacement in the plastics industry. Previous studies have shown that BPA and BPS exhibit similar effects on reproduction in fish and rodent species. BPS reportedly alters steroidogenesis in bovine granulosa cells. Luteinised granulosa cells collected from 59 women who were undergoing an in vitro fertilization procedure were cultured for 48 h in the presence or absence of BPS (10 nM, 100 nM, 1 µM, 10 µM or 50 µM). BPS exposure was investigated by assessing follicular fluids from these 59 women for their BPS content. Culture medium, cells, total messenger RNA (mRNA) and total protein extracted from the luteinised granulosa cells were examined for oestradiol and progesterone secretion, cellular proliferation, viability, gene expression, steroidogenic enzyme expression and cell signaling. BPS was measured in follicular fluids using mass spectrometry. Exposure of granulosa cells to 10 or 50 µM BPS for 48 h induced a 16% (p = 0.0059) and 64% (p < 0.0001) decrease, respectively, in progesterone secretion; 50 µM BPS decreased oestradiol secretion by 46% (p < 0.0001). Ten µM BPS also tended to reduce CYP11A1 protein expression by 37% (p = 0.0947) without affecting HSD3B1 and CYP19A1 expression. Fifty µM BPS increased ERRγ expression. Environmental levels of BPS (nanomolar range) did not induce changes in steroidogenesis in human granulosa cells. The effects of BPS were observed after only 48 h of BPS exposure. These acute effects might be similar to chronic effects of physiological BPS levels.

Bisphenol S Impaired In Vitro Ovine Early Developmental Oocyte Competence

INTRODUCTION

Bisphenol A (BPA) is a widespread compound in the plastic industry that is especially used to produce baby bottles, food packaging and metal cans. BPA, an endocrine disruptor, leads to alterations in reproductive function and therefore has been banned from the food industry. Unregulated BPA analogues, particularly Bisphenol S (BPS), have emerged and are now used in the plastic industry. Thus, this study aimed to examine the acute effects of low and environmental doses of BPS on ewe oocyte quality and developmental competence, and its mechanism of action, during in vitro maturation.

METHODS

Ewe cumulus-oocyte complexes underwent in vitro maturation in the presence or absence of BPS (1 nM, 10 nM, 100 nM, 1 µM or 10 µM). Oocytes were then subjected to in vitro fertilisation and development.

RESULTS

1 µM BPS induced a 12.7% decrease in the cleavage rate (p = 0.004) and a 42.6% decrease in the blastocyst rate (p = 0.017) compared to control. The blastocyst rate reduction was also observed with 10 nM BPS. Furthermore, 10 µM BPS reduced the oocyte maturation rate, and 1 µM BPS decreased cumulus cell progesterone secretion. PR and AMH gene expression were reduced in cumulus cells. BPS induced a 5-fold increase in MAPK 3/1 activation (p = 0.04).

CONCLUSIONS

BPS impaired ewe oocyte developmental competence. The data suggest that BPS might not be a safe BPA analogue. Further studies are required to elucidate its detailed mechanism of action.

Mammalian ovarian lipid distributions by desorption electrospray ionization-mass spectrometry (DESI-MS) imaging

Merging optical images of tissue sections with the spatial distributions of molecules seen by imaging mass spectrometry is a powerful approach to better understand the metabolic roles of the mapped molecules. Here, we use histologically friendly desorption electrospray ionization-mass spectrometry (DESI-MS) to map the lipid distribution in tissue sections of ovaries from cows (N = 8), sows (N = 3), and mice (N = 12). Morphologically friendly DESI-MS imaging allows the same sections to be examined for morphological information. Independent of the species, ovarian follicles, corpora lutea, and stroma could be differentiated by principal component analysis, showing that lipid profiles are well conserved among species. As examples of specific findings, arachidonic acid and the phosphatidylinositol PI(38:4), were both found concentrated in the follicles and corpora lutea, structures that promoted ovulation and implantation, respectively. Adrenic acid was spatially located in the corpora lutea, suggesting the importance of this fatty acid in the ovary luteal phase. In summary, lipid information captured by DESI-MS imaging could be related to ovarian structures and data were all conserved among cows, sows, and mice. Further application of DESI-MS imaging to either physiological or pathophysiological models of reproductive conditions will likely expand knowledge of the roles of specific lipids and pathways in ovarian activity and mammalian fertility. Graphical abstract Desorption electrospray ionization-mass spectrometry (DESI-MS) is performed directly from frozen ovarian tissue sections placed onto glass slides. Because the desorption and ionization process of small molecules is so gentle, the tissue architecture is preserved. The sample can then be stained and tissue morphology information can be overlaid with the chemical information obtained by DESI-MS.

Colocalization of GPR120 and anterior pituitary hormone-producing cells in female Japanese Black cattle

Negative energy balance in domestic animals suppresses their reproductive function. These animals commonly use long-chain fatty acids (LCFAs) from adipocytes as an energy source under states of malnutrition. The G-protein coupled receptor, GPR120, is a specific receptor for LCFAs, but its role in reproductive function remains unknown in domestic animals. The purpose of this study was to examine whether GPR120 is involved in the reproductive system of cattle. GPR120 mRNA expression was evaluated in brain, pituitary, and ovarian tissue samples by RT-PCR. GPR120 gene expression was detected with high intensity only in the anterior pituitary sample, and GPR120-immunoreactive cells were found in the anterior pituitary gland. Double immunohistochemistry of GPR120 in the anterior pituitary hormone-producing cells, such as gonadotropes, thyrotropes, lactotropes, somatotropes, and corticotropes, was performed to clarify the distribution of GPR120 in the anterior pituitary gland of ovariectomized heifers. Luteinizing hormone β subunit (LHβ)- and follicle-stimulating hormone β subunit (FSHβ)-immunoreactive cells demonstrated GPR120 immunoreactivity at 80.7% and 85.9%, respectively. Thyrotropes, lactotropes, somatotropes, and corticotropes coexpressed GPR120 at 21.1%, 5.4%, 13.6%, and 14.5%, respectively. In conclusion, the present study suggests that GPR120 in the anterior pituitary gland might mediate LCFA signaling to regulate gonadotrope functions, such as hormone secretion or production, in cattle.

Maternal supplementation with fish oil modulates inflammation-related MicroRNAs and genes in suckling lambs

Dietary n-3 long-chain fatty acids (n-3 LCFA) have been shown to modify lipid metabolism and immune function. The objective of this study was to evaluate the effect of periparturient fish oil (FO) supplementation on the inflammation and metabolic health of ewes and their lambs at a molecular level. Prepartum ewes were fed control diet (CON, n = 12) or CON supplemented with 2% DM of calcium soap of FO (n = 12) from 28 days before until 21 days after parturition. The ewes were evaluated for plasma metabolites and milk composition. The experiment was followed by analyzing the relative transcript abundance of circulating microRNAs (miRNAs) in plasma and targeted miRNA/mRNA expression in peripheral blood mononuclear cells (PBMCs) in both ewes and lambs. FO treatment decreased prepartum feed intake (1812 ± 35 vs 1674 ± 33 g/day, P < 0.01), whereas the influence on plasma metabolites was negligible. Dietary FO supplementation decreased milk fat percentage (8.82 ± 0.49 vs 7.03 ± 0.45, P = 0.02) and reduced milk n-6/n-3 (P < 0.05). Also, it altered the expression of plasma-circulating miRNAs in both ewe and lamb (P < 0.05). Furthermore, maternal nutrition of FO downregulated the relative expression of miR-33a and miR-146b and transcript abundance of genes IL-1β (0.41-fold) and NF-κB (0.25-fold) in lambs' PBMC. In conclusion, results showed that FO supplementation starting antepartum affects milk composition and circulating miRNA in dams and the inflammatory markers in lambs delivered by the supplemented ewes. These may provide a strategy to maintain immune balance during gestation and develop the immune system in lambs.

Functional expression of the free fatty acids receptor-1 and -4 (FFA1/GPR40 and FFA4/GPR120) in bovine endometrial cells

Endometrial epithelial cells play a key defensive role as part of the innate immune response of cow uterus. An association between risk of acquiring infectious diseases and increased levels of free fatty acids postpartum has been suggested, and the use of omega-3 fatty acids such as docosahexaenoic acid (DHA) has been proposed as a beneficial strategy to improve immunity and fertility. The goal of our study was to demonstrate the presence of free fatty acid (FFA)-1 and 4 receptors in endometrial cells and to investigate their role on DHA interference in lipopolysaccharide (LPS)-induced inflammatory endometrial activation. We demonstrated that the bovine endometrial (BEND) cells line and bovine endometrium express both FFA1 and FFA4 receptors. FFA1 and FFA4 receptors were localized in the epithelium lining the endometrial cavity and in endometrial glands whereas in BEND cells a characteristic cell membrane localization of both receptors was observed. DHA, a FFA4 natural agonist, increased intracellular calcium mobilization in BEND cells, but the FFA1 agonists oleic and linoleic acids did not increase this response. DHA-induced intracellular calcium mobilization was inhibited by the FFA4 and FFA1 antagonists AH7614 and GW1100, respectively. DHA significantly reduced LPS-induced prostaglandin E2 (PGE2) production, but none of the antagonists reduced the effect produced by DHA. On the contrary, linoleic acid increased LPS-induced PGE2 production. In conclusion, endometrial cells express FFA4 and FFA1 receptors, and DHA induces intracellular calcium release via FFA4 and FFA1 receptors. DHA reduces PGE2, but this response was not mediated by FFA4 or FFA1 receptors.