Tongue Leptin Decreases Oro-Sensory Perception of Dietary Fatty Acids

Leptin, an anorectic hormone, regulates food intake, energy expenditure and body weight. We assessed the implication of tongue leptin in the modulation of oro-sensory detection of dietary fatty acids in mice. The RT-PCR analysis showed that mRNA encoding leptin and leptin receptor (Ob-Rb) was expressed in mice taste bud cells (TBC). Confocal microscopic studies showed that the lipid sensor CD36 was co-expressed with leptin in mice TBC. Silencing of leptin or Ob-Rb mRNA in tongue papillae upregulated preference for a long-chain fatty acid (LCFA), i.e., linoleic acid (LA), in a two-bottle paradigm in mice. Furthermore, tongue leptin application decreased the preference for the LCFA. These results suggest that tongue leptin exerts an inhibitory action on fatty acid preference. In isolated mice TBC, leptin decreased LCFA-induced increases in free intracellular calcium concentrations, [Ca2+]i. Leptin and LCFA induced the phosphorylation of ERK1/2 and STAT-3 and there were no additive or opposite effects of the two agents on the degree of phosphorylation. However, leptin, but not the LCFA, induced phosphoinositide-3-kinase (PI-3-K)-dependent Akt phosphorylation in TBC. Furthermore, leptin induced hyperpolarization, whereas LCFA induced depolarization in TBC. Our study demonstrates that tongue leptin exerts an inhibitory action on oro-sensory detection of a dietary fatty acid by interfering with Ca2+ signaling and membrane potential in mice TBC.

Impact of oral lipid and glucose tolerance tests on the postprandial concentrations of angiopoietin-like proteins (Angptl) 3 and 4

Background The postprandial regulation of angiopoietin-like proteins (Angptls) and their expression in adipocytes is poorly characterized. Objective Circulating Angptl3 and 4 were analyzed in healthy individuals undergoing either an oral lipid tolerance test (OLTT; n = 98) or an oral glucose tolerance test (OGTT; n = 99). Venous blood was drawn after 0, 2, 4, and 6 h during OLTT and after 0, 1, and 2 h during OGTT. Anthropometric and laboratory parameters were assessed and concentrations of Angptls were quantified by enzyme-linked immunosorbent assay. Angptl gene expression in 3T3-L1 adipocytes and in murine adipose tissues and cellular fractions was analyzed by quantitative real-time PCR. Results Angptl3 concentrations significantly decreased while Angptl4 levels continuously increased during OLTT. Both proteins remained unaffected during OGTT. Angptl3 and Angptl4 were expressed in murine subcutaneous and visceral AT with higher mRNA levels in mature adipocytes when compared to the stroma-vascular cell fraction. Both proteins were strongly induced during 3T3-L1 adipocyte differentiation and they were unresponsive to glucose in mature fat cells. Adipocyte Angptl3 (but not Angptl4) mRNA expression was inhibited by the polyunsaturated fatty acids arachidonic acid and docosahexaenoic acid, whereas nine types of dietary fatty acids remained without any effect. Conclusions There is evidence of short-time regulation of Angptl3/4 levels upon metabolic stress. Angptl4 expression is high and Angptl3 expression is low in AT and restricted mainly to mature adipocytes without any differences concerning fat compartments. Whereas dietary fatty acids and glucose are without any effect, omega-3/-6-polyunsaturated fatty acids inhibited Anptl3 expression in adipocytes.

Association of different types of dietary fatty acids with breast cancer, a case-control study

Purpose The purpose of this study is to explore the association between intake of different types of dietary fats with breast cancer (BC) risk in Iranian women. Design/methodology/approach A total of 540 women (180 women with BC and 360 healthy women) were recruited from Shohadaye Tajrish hospital, Tehran, Iran. Data on anthropometric measurements, physical activity, smoking and alcohol consumption were collected. The food frequency questionnaire was used to assess the intake of fatty acids including saturated fatty acids, mono unsaturated fatty acids, poly unsaturated fatty acids, macronutrients, total fat, cholesterol, and calorie. Findings The cases had significantly higher BMI (29.19 ± 3.2 vs 27.27 kg/m2 ± 2.8) and higher intake of calorie (2737 ± 925 vs 2315 ± 1066 kcal/d, P = 0.01), carbohydrate (402 ± 125 vs 312 ± 170 kcal/d, P = 0.01) and ω−6 fatty acids (5.45 ± 6.9 vs 3.39 ± 0.59 g/d, P = 0.001) compared to the control group . Higher consumption of ω−6 fatty acids was related with higher risk of BC (OR = 5.429, CI95%:2.5–11.79, P = 0.001) The association between BC and intake of omega-6 fatty acids remained significant after adjustments for age, BMI, for using alcohol drinks, smoking, physical activity, calorie intake, protein intake and carbohydrate intake. Originality/value There are insufficient studies to investigate the association of different types of fatty acids with BC. This study found that higher omega-6 fatty acids intake was associated with increased risk of BC in women.

Dietary Fatty Acids, Macronutrient Substitutions, Food Sources and Incidence of Coronary Heart Disease: Findings From the EPIC‐CVD Case‐Cohort Study Across Nine European Countries

Background There is controversy about associations between total dietary fatty acids, their classes (saturated fatty acids [SFAs], monounsaturated fatty acids, and polyunsaturated fatty acids), and risk of coronary heart disease (CHD). Specifically, the relevance of food sources of SFAs to CHD associations is uncertain. Methods and Results We conducted a case‐cohort study involving 10 529 incident CHD cases and a random subcohort of 16 730 adults selected from a cohort of 385 747 participants in 9 countries of the EPIC (European Prospective Investigation into Cancer and Nutrition) study. We estimated multivariable adjusted country‐specific hazard ratios (HRs) and 95% CIs per 5% of energy intake from dietary fatty acids, with and without isocaloric macronutrient substitutions, using Prentice‐weighted Cox regression models and pooled results using random‐effects meta‐analysis. We found no evidence for associations of the consumption of total or fatty acid classes with CHD, regardless of macronutrient substitutions. In analyses considering food sources, CHD incidence was lower per 1% higher energy intake of SFAs from yogurt (HR, 0.93 [95% CI, 0.88–0.99]), cheese (HR, 0.98 [95% CI, 0.96–1.00]), and fish (HR, 0.87 [95% CI, 0.75–1.00]), but higher for SFAs from red meat (HR, 1.07 [95% CI, 1.02–1.12]) and butter (HR, 1.02 [95% CI, 1.00–1.04]). Conclusions This observational study found no strong associations of total fatty acids, SFAs, monounsaturated fatty acids, and polyunsaturated fatty acids, with incident CHD. By contrast, we found associations of SFAs with CHD in opposite directions dependent on the food source. These findings should be further confirmed, but support public health recommendations to consider food sources alongside the macronutrients they contain, and suggest the importance of the overall food matrix.

Effects of Dietary Fatty Acids on Gene Expression and Biological Processes in Different Tissues of Pigs: A Review

Studies on the influence of dietary components and their effects are fundamental for nutrigenomics, or the study of how nutrients can be cellular sensors, how they affect biological processes and gene expression in different tissues. Lipids are an important source of fatty acids (FA) and energy and are fundamental to biological processes and influence the regulation of transcription. Pigs are excellent model to study nutrigenomics, particularly lipid metabolism because the deposition and composition of FA in their tissues reflect the composition of FA in their diet. Recent studies show that FA supplementation is important in production systems, such as growing and finishing pigs, as it can improve the energy value of the feed, help reduce costs, improve animal welfare, and influence the nutritional value of the meat. Studies show that oleic (OA), linoleic (LA), docosahexaenoic (DHA), and eicosapentaenoic (EPA) acids are associated with the regulation of transcription in tissues such as muscle, liver, adipose tissue, and brain. Other studies indicate that EPA and DHA are associated with changes in specific signaling pathways, altering gene expression and biophysical properties of membranes. This review, therefore, focuses on the current knowledge of the effects of dietary FA on production traits and gene expression.

The role of the gut microbiota in the effects of early-life stress and dietary fatty acids on later-life central and metabolic outcomes in mice

Early-life stress (ELS) leads to increased vulnerability for mental and metabolic disorders. We have previously shown that dietary low ω-6/ω-3 polyunsaturated fatty acid (PUFA) ratio is able to protect against ELS-induced cognitive impairments. Due to the importance of the gut microbiota as determinants of long-term health, we here study the impact of ELS and dietary PUFA’s on the gut microbiota, and how this relates to the previously described cognitive, metabolic and fatty acid profiles. Male mice were exposed to ELS via the limited bedding and nesting paradigm (postnatal day (P)2 – P9) and to an early diet (P2 – P42) with either high (15) or low (1) ω-6 linoleic acid to ω-3 alpha-linolenic acid ratio. 16S ribosomal RNA was sequenced and analyzed from fecal samples at P21, P42 and P180. ELS increased β-diversity which persisted into adulthood. The low ω-6/ω-3 diet prevented the ELS-induced increase in β-diversity, at P42. At the level of taxa abundance, for example, the abundance of the phyla Bacteroidetes increased while Actinobacteria and Verrucomicrobia decreased with age; ELS reduced the relative abundance of the genera RC9 gut group and Rikenella into adulthood and the low ω-6/ω-3 diet reduced the abundance of the Firmicutes Erysipelotrichia. At P42, species abundance correlated with body fat mass and circulating leptin (e.g. Bacteroidetes and Proteobacteria taxa) and fatty acid profiles (e.g. Firmicutes taxa). This study gives novel insights into the impact of age, ELS and dietary PUFAs on microbiota composition, providing potential targets for non-invasive (nutritional) modulation of the ELS-induced deficits.

Growth and Lipidomic Analyses of Penaeus monodon Larvae Supplemented With Aurantiochytrium limacinum BCC52274

Long-chain polyunsaturated fatty acids (LC-PUFAs) are essential for growth and health of larval marine animals. Marine animals have a limited capability for LC-PUFA synthesis, and the larvae must obtain LC-PUFAs from diet. The protist Aurantiochytrium limacinum (AL) is abundant in 22:6 n-3 (docosahexaenoic acid, DHA), 22:5 n-3 (docosapentaenoic acid, DPA) and 16:0 fatty acids, which qualifies it as an LC-PUFA source for feed application. Therefore, in this study, a common feed containing lower amounts of total LC-PUFAs, Thalasiosira weissflogii, was replaced with AL at graded proportions and supplied to Penaeus monodon larvae from mysis (M) 1 to post-larval (PL) 2 stages to supplement LC-PUFAs in the diet. After that, all shrimp from PL2 to PL12 were continuously reared and subjected to the same diet regime, which was a combination of Artemia and commercial dried feed. The AL-supplemented PL2 shrimp demonstrated marked accumulation of the key fatty acids present in AL—16:0, DPA and DHA. The supplemented larvae showed no difference in growth during the supplementation period from M1 to PL2; however, average body weight and biomass were increased in PL12 shrimp that were fed earlier with AL. Lipidomic analysis revealed that profiles of fatty acids but not lipid classes/subclasses in PL shrimp reflected the supplied diet. The main saturated fatty acid (SFA, 16:0) predominantly accumulated in acylglycerols, which are energy-reserve lipids, in PL2 shrimp. Both LC-PUFAs (DHA and DPA) were preferentially deposited in phospholipids or structural lipids. Furthermore, while the amounts of both LC-PUFAs increased along with the amount of supplied AL, that of the SFA did not. This suggests that LC-PUFAs were prioritized to be stored over SFA when both types of fatty acids were present in high amounts. This analysis substantiates the importance of LC-PUFAs and provides an insight into how different types of the dietary fatty acids were differentially accumulated in lipid classes and subclasses for their biological functions.

In Utero Exposure to trans-10, cis-12 Conjugated Linoleic Acid Modifies Postnatal Development of the Mammary Gland and its Hormone Responsiveness

We previously showed that dietary trans-10, cis-12 conjugated linoleic acid (10,12 CLA) stimulates estrogen-independent mammary growth in young ovariectomized mice. Here we investigated the effects of in utero or postnatal exposure to cis-9, trans-11 (9,11 CLA) and 10,12 CLA on postnatal development of the mammary gland and its responsiveness to ovarian steroids. In the first experiment we fed dams different CLA prior to and during gestation, then cross fostered female pups onto control fed dams prior to assessing the histomorphology of their mammary glands. Pregnant dams in the second experiment were similarly exposed to CLA, after which their female pups were ovariectomized then treated with 17β-estradiol (E), progesterone (P) or E + P for 5 days. In a third experiment, mature female mice were fed different CLA for 28 days prior to ovariectomy, then treated with E, P or E + P. Our data indicate that 10,12 CLA modifies the responsiveness of the mammary glands to E or E + P when exposure occurs either in utero, or postnatally. These findings underline the sensitivity of the mammary glands to dietary fatty acids and reinforce the potential for maternal nutrition to impact postnatal development of the mammary glands and their risk for developing cancer.