Adipose Tissue Composition Research Articles

MicroRNA-126b-5p Exacerbates Development of Adipose Tissue and Diet-Induced Obesity.

Obesity has become a worldwide epidemic, caused by many factors such as genetic regulatory elements, unhealthy diet, and lack of exercise. MicroRNAs (miRNAs) are non-coding single-stranded RNA classes, which are about 22 nucleotides in length and highly conserved among species. In the last decade, a series of miRNAs were identified as therapeutic targets for obesity. In the present study, we found that miR-126b-5p was associated with adipogenesis. miR-126b-5p overexpression promoted the proliferation of 3T3-L1 preadipocytes by upregulating the expression of proliferation-related genes and downregulating the expression of apoptosis-related genes; the inhibition of miR-126b-5p gave rise to opposite results. Similarly, miR-126b-5p overexpression could promote the differentiation of 3T3-L1 preadipocytes by increasing the expression of lipid deposition genes and triglyceride (TG) and total cholesterol (TC) levels. Moreover, luciferase reporter assay demonstrated that adiponectin receptor 2 (Adipor2) and acyl-CoA dehydrogenase, long chain (ACADL) were the direct target genes of miR-126b-5p. Moreover, overexpression of miR-126b-5p could exacerbate the clinical symptoms of obesity when mice were induced by a high-fat diet, including increased adipose tissue weight, adipocyte volume, and insulin resistance. Interestingly, overexpression of miR-126b-5p in preadipocytes and mice could significantly increase total fatty acid content and change the fatty acid composition of adipose tissue. Taken together, the present study showed that miR-126b-5p promotes lipid deposition in vivo and in vitro, indicating that miR-126b-5p is a potential target for treating obesity.

Tissue cholesterol metabolism and prostate cancer aggressiveness: Ethno-geographic variations.

Prostate cancer (PCa) is more frequent and more aggressive in populations of African descent than in Caucasians. Since the fatty acid composition of peri-prostatic adipose tissue (PPAT) has been shown to differ according to the ethno-geographic origin and is involved in PCa aggressiveness, we aimed to analyze the cholesterol content of PPAT from Caucasian and African-Caribbean patients, in correlation with markers of disease aggressiveness and cholesterol metabolism in cancer tissues. The quantification of cholesterol in PPAT was analyzed in 52 Caucasian and 52 African-Caribbean PCa patients, with in each group 26 indolent tumors (ISUP Group1 and pT2) and 26 potentially aggressive tumors (ISUP Group 3-5 and/or pT3). The expression of proteins involved in cholesterol metabolism was analyzed by immunohistochemistry on cancer tissue samples included in tissue microarrays. The amount of cholesterol esters was lower in PPAT from African-Caribbean patients compared with Caucasians, without any correlation with markers of disease aggressiveness. In cancer tissues from African-Caribbean patients, the expression of ABCA1 (involved in cholesterol efflux) was decreased, and that of SREBP-2 (involved in cholesterol uptake) was increased. In both groups of patients, SREBP-2 expression was strongly associated with that of Zeb1, a key player in the epithelial-to-mesenchymal transition (EMT) process. These results suggest that cholesterol metabolism differs according to the ethno-geographic origin, in both PPAT and cancer tissues. In African-Caribbeans, the orientation towards accumulation of cholesterol in cancer cells is associated with a more frequent state of EMT, which may promote PCa aggressiveness in this population.

Liver Fat, Adipose Tissue, and Body Composition Changes After Switching from a Protease Inhibitor or Efavirenz to Raltegravir.

Integrase inhibitors appear to increase body weight, but paradoxically some data indicate that raltegravir (RAL) may decrease liver fat. Our objective was to study the effects of switching from a protease inhibitor (PI) or efavirenz (EFV) to RAL on liver fat, body composition, and metabolic parameters among people living with HIV (PLWH) with high risk for nonalcoholic fatty liver disease (NAFLD). We randomized overweight PLWH with signs of metabolic syndrome to switch a PI or EFV to RAL (n = 19) or to continue unchanged antiretroviral therapy (control, n = 24) for 24 weeks. Liver fat was measured by magnetic resonance spectroscopy (MRS), body composition by magnetic resonance imaging, and bioimpedance analysis; subcutaneous fat biopsies were obtained. Median (interquartile range) liver fat content was normal in RAL 2.3% (1.1-6.0) and control 3.1% (1.6-7.3) group at baseline. Liver fat and visceral adipose tissue remained unchanged during the study. Body weight [from 85.9 kg (76.1-97.7) to 89.3 (78.7-98.7), p = 0.019], body fat mass [from 20.3 kg (14.6-29.7) to 22.7 (17.0-29.7), p = 0.015], and subcutaneous adipose tissue (SAT) volume [from 3979 mL (2068-6468) to 4043 (2206-6433), p = 0.048] increased, yet, adipocyte size [from 564 pL (437-733) to 478 (423-587), p = 0.019] decreased in RAL but remained unchanged in control group. Circulating lipids and inflammatory markers improved in RAL compared to control group. The median liver fat measured by MRS was unexpectedly within normal range in this relatively small study population with presumably high risk for NAFLD contradicting high prevalence of NAFLD reported with other methods. Despite weight gain, increase in SAT together with decreased adipocyte size and reduced inflammation may reflect improved adipose tissue function. Clinical Trial Registration number: NCT03374358.

Long-term cardiac risk in individuals with low calcium score on coronary computed tomography angiography can be stratified by the pericoronary fat radiomic profile (FRP)

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): UKRI, British Heart Foundation Background Inflammation in the coronaries induces macroscopic changes in perivascular adipose tissue composition, detectable by the pericoronary Fat Radiomic Profile (FRP) on coronary computed tomography angiography (CCTA). Purpose To assess the ability of FRP to stratify cardiac risk in patients with Coronary Artery Calcium (CAC) score below 100 following routine CCTA. Methods 1,575 participants from the CCTA arm of the SCOT-HEART trial (NCT01149590) eligible for image analysis were included. Pericoronary FRP mapping was performed in perivascular adipose tissue segmentations around the proximal sites of the right and left coronary arteries, as previously validated. We first tested the prognostic value of FRP in the sub-cohort of patients with CAC < 100. We further analysed a sub-group based on the absence of high risk plaque (HRP) features and obstructive coronary artery disease (CAD). The association with future incidence of major adverse cardiac events (MACE: cardiac mortality or non-fatal myocardial infarction) or a composite endpoint of MACE ± late revascularization (MACE-ReVasc) was assessed using adjusted Cox regression models [adjusted for age, sex, systolic blood pressure (SBP), diabetes mellitus (DM), body mass index (BMI), smoking, CAD (≥50% stenosis), total cholesterol, high-density lipoprotein (HDL), and HRP features]. Results In total, 1,032 patients (53.9% female sex) were found with low CAC score (CAC < 100), with a median age of 55 years. Over a mean follow-up of 4.87 ± 1.06 years, 12 MACE and 47 MACE-ReVasc were recorded. High FRP was associated with a 14.4-fold (95% CI: 3.80-54.78, p < 0.001) higher adjusted risk of MACE and a 2.8-fold (95% CI: 1.49-5.36, p = 0.001) higher adjusted risk of MACE-ReVasc (A). Addition of high FRP to a baseline model consisting of traditional risk factors (age, sex, systolic blood pressure, diabetes mellitus, BMI, smoking, CAD (≥50% stenosis), total cholesterol, HDL, HRP) significantly enhanced (deltaAUC at 5 years:0.15, p = 0.03) the model’s performance and reclassified individuals (NRI = 0.59, p = 0.02, B). Interestingly, after more rigorous filtering of the population by absence of HRP features and obstructive CAD, high FRP remained an independent predictor of MACE (n = 756, Adj.HR = 28.1, p = 0.003). Conclusion In individuals with low CAC scores the Fat Radiomic Profile biormarker significantly improves risk prediction for adverse clinical events beyond the current state-of-the-art. Non-invasive profiling of pericoronary adipose tissue using CCTA-derived FRP captures irreversible changes in perivascular adipose tissue composition associated with chronic vascular inflammation and atherosclerotic disease, and can supplement the traditional anatomical assessment of the coronary vasculature with a functional marker of disease activity.

Atorvastatin Attenuates Vascular Remodeling in Mice with Metabolic Syndrome.

ResumoFundamento A síndrome metabólica é caracterizada por um conjunto de comorbidades. Durante a síndrome, observam-se alterações estruturais no sistema cardiovascular, especialmente o remodelamento vascular. Uma das causas predisponentes para essas alterações é a inflamação crônica oriunda de mudanças na estrutura e composição do tecido adiposo perivascular. Atorvastatina é eficaz no tratamento das dislipidemias. No entanto, seus efeitos pleiotrópicos não são totalmente compreendidos. Supõe-se que, durante a síndrome metabólica, ocorre remodelamento vascular e que o tratamento com atorvastatina pode ser capaz de atenuar tal condição.Objetivos Avaliar os efeitos do tratamento com atorvastatina sobre o remodelamento vascular em modelo experimental de síndrome metabólica.Métodos Camundongos Swiss receberam dieta controle ou dieta hiperglicídica por 18 semanas. Após 14 semanas de dieta, os camundongos foram tratados com veículo ou atorvastatina (20mg/kg) durante 4 semanas. Foram avaliados o perfil nutricional e metabólico por testes bioquímicos; análise estrutural da artéria aorta por histologia e dosagem de citocinas por ensaio imunoenzimático. O nível de significância aceitável para os resultados foi p <0,05.Resultados A dieta hiperglicídica promoveu o desenvolvimento de síndrome metabólica. Tal fato culminou no remodelamento hipertrófico do músculo liso vascular e tecido adiposo perivascular. Além disso, houve aumentos das citocinas TNF-α e IL-6 circulantes e no tecido adiposo perivascular. O tratamento com atorvastatina reduziu significativamente os danos metabólicos, o remodelamento vascular e os níveis de citocinas.Conclusão Atorvastatina ameniza danos metabólicos associados à síndrome metabólica induzida por dieta hiperglicídica, além de atenuar o remodelamento vascular, sendo esses efeitos associados à redução de citocinas pró-inflamatórias.

Filling the Gap: Entirely Beige/Brite Adipose Tissues in One of the Smallest Mammals, Suncus etruscus

Mammalian brown adipose tissue provides a means of non-shivering thermogenesis to defend normothermia in the cold by uncoupling protein 1 (UCP1) mediated uncoupling of mitochondrial respiration from ATP production. Apart from brown adipose tissue, thermogenic beige/brite adipocytes reside interspersed within white adipose tissue depots. In rodents, the number of beige/brite adipocytes is highly variable and adapts to thermogenic requirements. We here studied adipose tissue composition of the Etruscan shrew S. etruscus, an insectivore and one of the smallest known mammals with a consequently extreme thermogenic demand in its temperate habitat with cold winters. By dissection, phase contrast computer tomography, histology and mitochondrial enzyme activity assays, we mapped the distribution of adipose tissue depots in shrews from a research colony kept at room temperature. In similar anatomical locations as typically found in rodents, an especially large amount of brown adipose tissue concentrated to the interscapular and subscapular region, while white adipose tissue with a very high content of multilocular cells formed the inguinal and gluteal depots. Uniquely, shrews featured a large, interrenal adipose tissue that by visual inspection, mitochondrial density, fat content, UCP1 transcript abundance, histological analysis and mitochondrial enzyme activity appeared to be an intermediate between classical brown and very beige/brite adipose tissue. This unusual, centrally located depot expansively sheathed both the Vena cava inferior and the Aorta abdominalis, the two largest blood vessels, and must be assumed to provide considerable thermogenic capacity. In conclusion, we identified a novel adipose tissue depot with unique properties placing it in between very beige/brite and brown adipose tissue. Importantly, this finding fills in a conceptual gap within our understanding of adipose tissue plasticity previously thought to include a range from white to beige/brite on the one end, and brown on the other. Etruscan shrew fat depots, however, demonstrate the existence of a gapless continuum of white-to-brown characteristics. Functionally, the transitional, interrenal depot appears strategically placed to deliver heat into circulation via the penetrating, large blood vessels in an animal with extreme thermogenic demand.

Leptin, Acting at Central Level, Increases FGF21 Expression in White Adipose Tissue via PPARβ/δ.

The altered function of adipose tissue can result in obesity, insulin resistance, and its metabolic complications. Leptin, acting on the central nervous system, modifies the composition and function of adipose tissue. To date, the molecular changes that occur in epididymal white adipose tissue (eWAT) during chronic leptin treatment are not fully understood. Herein we aimed to address whether PPARβ/δ could mediate the metabolic actions induced by leptin in eWAT. To this end, male 3-month-old Wistar rats, infused intracerebroventricularly (icv) with leptin (0.2 μg/day) for 7 days, were daily co-treated intraperitoneally (ip) without or with the specific PPARβ/δ receptor antagonist GSK0660 (1 mg/kg/day). In parallel, we also administered GSK0660 to control rats fed ad libitum without leptin infusion. Leptin, acting at central level, prevented the starvation-induced increase in circulating levels of FGF21, while induced markedly the endogenous expression of FGF21 and browning markers of eWAT. Interestingly, GSK0660 abolished the anorectic effects induced by icv leptin leading to increased visceral fat mass and reduced browning capacity. In addition, the pharmacological inhibition of PPARβ/δ alters the immunomodulatory actions of central leptin on eWAT. In summary, our results demonstrate that PPARβ/δ is involved in the up-regulation of FGF21 expression induced by leptin in visceral adipose tissue.

Segmentation and Linear Measurement for Body Composition Analysis using Slice-O-Matic and Horos.

Body composition is associated with risk of disease progression and treatment complications in a variety of conditions. Therefore, quantification of skeletal muscle mass and adipose tissues on Computed Tomography (CT) and/or Magnetic Resonance Imaging (MRI) may inform surgery risk evaluation and disease prognosis. This article describes two quantification methods originally described by Mourtzakis et al. and Avrutin et al.: tissue segmentation and linear measurement of skeletal muscle. Patients' cross-sectional image at the midpoint of the third lumbar vertebra was obtained for both measurements. For segmentation, the images were imported into Slice-O-Matic and colored for skeletal muscle, intramuscular adipose tissue, visceral adipose tissue, and subcutaneous adipose tissue. Then, surface areas of each tissue type were calculated using the tag surface area function. For linear measurements, the height and width of bilateral psoas and paraspinal muscles at the level of the third lumbar vertebra are measured and the calculation using these four values yield the estimated skeletal muscle mass. Segmentation analysis provides quantitative, comprehensive information about the patients' body composition, which can then be correlated with disease progression. However, the process is more time-consuming and requires specialized training. Linear measurements are an efficient and clinic-friendly tool for quick preoperative evaluation. However, linear measurements do not provide information on adipose tissue composition. Nonetheless, these methods have wide applications in a variety of diseases to predict surgical outcomes, risk of disease progression and inform treatment options for patients.

Normalized glandular dose coefficients for digital breast tomosynthesis systems with a homogeneous breast model

This work aims at calculating and releasing tabulated values of dose conversion coefficients, DgNDBT, for mean glandular dose (MGD) estimates in digital breast tomosynthesis (DBT). The DgNDBT coefficients are proposed as unique conversion coefficients for MGD estimates, in place of dose conversion coefficients in mammography (DgNDM or c, g, s triad as proposed in worldwide quality assurance protocols) used together with the T correction factor. DgNDBT is the MGD per unit incident air kerma measured at the breast surface for a 0° projection and the entire tube load used for the scan. The dataset of polyenergetic DgNDBT coefficients was derived via a Monte Carlo software based on the Geant4 toolkit. Dose coefficients were calculated for a grid of values of breast characteristics (breast thickness in the range 20–90 mm and glandular fraction by mass of 1%, 25%, 50%, 75%, 100%) and the simulated geometries, scan protocols, irradiation geometries and typical spectral qualities replicated those of six commercial DBT systems (GE SenoClaire, Hologic Selenia Dimensions, GE Senographe Pristina, Fujifilm Amulet Innovality, Siemens Mammomat Inspiration and IMS Giotto Class). For given breast characteristics, target/filter combination, tube voltage and half value layer (HVL), two spectra with two HVL values have been simulated in order to permit MGD estimates from experimental HVL values via mathematical interpolation from tabulated values. The adopted breast model assumes homogenous composition of glandular and adipose tissues; it includes a 1.45 mm thick skin envelope in place of the 4–5 mm envelope commonly adopted in dosimetry protocols. The simulation code was validated versus AAPM Task group 195 Monte Carlo reference data sets (absolute differences not higher than 1.1%) and by comparison to relative dosimetry measurements with radiochromic film in a PMMA test object (differences within the maximum experimental uncertainty of 11%). The calculated coefficients show maximum relative deviations of −17.6% and +6.1% from those provided by the DBT dose coefficients adopted in the EUREF protocol and of 1.5%, on average, from data in the AAPM TG223 report. A spreadsheet is provided for interpolating the tabulated DgNDBT coefficients for arbitrary values of HVL, compressed breast thickness and glandular fraction, in the corresponding investigated ranges, for each DBT unit modeled in this work.

Subcutaneous adipose tissue composition and function are unaffected by liraglutide-induced weight loss in adults with type 1 diabetes.

Adipose tissue is the primary energy reservoir of the human body, which also possesses endocrine functions. The glucagon‐like peptide agonist liraglutide produces weight loss, although the specific effects on adipose tissue are unknown. We aimed to characterize the white adipose tissue composition and pericellular fibrosis of subcutaneous adipose tissue in response to liraglutide treatment. Furthermore, we explored the level of circulating free fatty acids, cluster of differentiation 163 (CD163) macrophage marker, leptin and adiponectin. Thirty‐nine adults with type 1 diabetes and polyneuropathy were randomly assigned to 26 weeks of liraglutide or placebo treatment. Biopsies of subcutaneous tissue were formalin‐fixed stained with picrosirius red to visualize collagen or immunohistochemically stained for CD163. Serum concentrations of free fatty acids, CD163, leptin and adiponectin were assessed with immunoassays or multiplex panels. In comparison with placebo, liraglutide induced weight loss (3.38 kg, 95% CI −5.29; −1.48, P < 0.001), but did not cause any differences in cell size, distribution of CD163‐positive cells, pericellular fibrosis and serum levels of free fatty acids, CD163, leptin or adiponectin (all P < 0.1). Additionally, no associations between weight loss, cell size and serum markers were found (all P > 0.08). In conclusion, despite liraglutide's effect on weight loss, sustained alterations in subcutaneous adipose tissue did not seem to appear.

30432 Novel insights from single-cell RNAseq analysis of the stromavascular fraction of human adipose tissue

ABSTRACT IMPACT: Characterizing the cellular composition of human adipose tissue may contribute to the prevention and/or treatment of obesity-associated metabolic diseases. OBJECTIVES/GOALS: Our aims in this study were to use single-cell techniques 1. to characterize cell types within the stromavascular fraction of human adipose tissue, 2. to identify subsets of cells within each type (sub-clustering), 3. to identify gene sets and pathways that may provide information on the function and significance of each cell cluster. METHODS/STUDY POPULATION: Abdominal subcutaneous adipose tissue samples from n=6 healthy volunteers (1M, 5F, age 28-38 y, BMI 24.5-63.0 kg/m2) were collected by aspiration or during surgery. In 3 subjects, all females, paired femoral samples were also collected. After collagenase digestion approximately n=10,000 cells/sample were used for single-cell RNA sequencing using the 10X Genomics platform. After QC and downstream analysis, data were analyzed in Seurat v.3.1.5. We identified first different cell types and then subclusters in an unbiased fashion. Gene Set Enrichment Analysis (GSEA) was used for pathway analysis. RESULTS/ANTICIPATED RESULTS: Progenitor markers are related to extracellular matrix, eg DCN (logFC progenitors vs other cells types=3.17, expressed in 99.7% (pct.1) of progenitors, 26.1% (pct.2) of others). Endothelial and pericytes shared markers like RBP7 (logFC=1.67, pct.1 0.88, pct.2 0.39); pericytes also showed unique markers, eg RGS5 (logFC=2.29, pct.1 0.89, pct.2 0.17). Progenitors are further divided into 11 sub-clusters, one of which showed enrichment of CD36 (high proliferation potential), FABP4 (differentiation), and of the novel marker PALMD (logFC=7.13, pct.1 0.94, pct.2 0.48). All p&lt;10E-5. GSEA analysis suggests that inflammatory pathways are downregulated in both adipose progenitors and endothelial/pericyte cells in the femoral compared to the abdominal depot. DISCUSSION/SIGNIFICANCE OF FINDINGS: Single cell RNA sequencing provides unique insights into the molecular profile of cell types and the identification of novel subsets of cells within the human adipose tissue. Such cellular heterogeneity may explain differences in adipose function between individuals and eventually in the risk of obesity-associated metabolic diseases.

Circulating Non-Esterified Fatty Acids as Biomarkers for Fat Content and Composition in Pigs.

Simple SummaryCirculating non-esterified fatty acids (NEFA) may be valuable as biomarkers for intramuscular fat content and fatty acid composition, as well as for other meat quality traits, in finishing heavy Duroc pigs. However, circulating NEFA composition may be affected by other factors such as age, fasting duration, and genetic variants related with adipogenesis and fatty acid metabolism pathways (e.g., SCD and LEPR). This study revealed that the circulating NEFA composition, especially the oleic acid content, reflects the metabolic status of an animal at a given time but has limited value as biomarker of intramuscular fat content and fatty acid composition.Circulating non-esterified fatty acids (NEFA) can reflect the composition of dietary fat or adipose tissues depending on the fasting conditions. Therefore, circulating NEFA may be valuable as biomarkers for meat quality traits, such as intramuscular fat content and fatty acid composition in finishing pigs. Genetic variants that regulate lipid metabolism can also modulate the circulating NEFA. We conducted an experiment with 150 heavy Duroc pigs to evaluate fluctuations in the circulating NEFA composition due to age, fasting duration and two genetic polymorphisms, one in the leptin receptor (LEPR; rs709596309) and one in the stearoyl-CoA desaturase (SCD; rs80912566) gene. Circulating NEFA were more saturated and less monounsaturated than the subcutaneous and intramuscular adipose tissues. Absolute circulating NEFA content was more influenced by fasting duration than age. The SCD polymorphism did not impact NEFA content or composition. The LEPR polymorphism affected the content but not the fatty acid composition. Circulating oleic acid NEFA content after a short fasting was positively correlated with intramuscular fat content and, after a long fasting, with intramuscular oleic acid content. We conclude that circulating NEFA reflect environmental and genetic metabolic changes but are of limited value as biomarkers for intramuscular fat content and fatty acid composition.

Evaluation of Supplemental Fat Sources and Pre-Farrow Essential Fatty Acid Intake on Lactating Sow Performance and Essential Fatty Acid Composition of Colostrum, Milk, and Adipose Tissue

Evaluation of Supplemental Fat Sources and Pre-Farrow Essential Fatty Acid Intake on Lactating Sow Performance and Essential Fatty Acid Composition of Colostrum, Milk, and Adipose Tissue

A Non-Synonymous Single Nucleotide Polymorphism in FASN Gene Alters FASN Enzyme Activity in Subcutaneous and Intramuscular Adipose Tissue in Holstein Friesian Steers

Abstract The FASN enzyme plays a key role in fatty acids synthesis as the main long-chain fatty acid synthesizer. A non-synonymous SNP (single nucleotide polymorphism) (g.17925A&gt;G) located in the thioesterase domain of this enzyme and an effect in fat deposition has been observed, but has not been evaluated in this breed and, moreover, the reason whereby this occurs remains unclear. The objective of this study was to evaluate the effect of this SNP on the activity of FASN enzyme in subcutaneous and intramuscular adipose tissue from Holstein Friesian steers. To achieve this, 196 animals were sampled in a local abattoir, genotyped for the FASN g.17924A&gt;G SNP and characterized for fatty acid profile. Then a sub-sample of 20 animals per genotype were selected to extract the total protein from subcutaneous and intramuscular adipose tissue to estimate the FASN enzyme activity. The FASN activity for each genotyped animal was assessed indirectly by measuring the decrease in the absorbance of NADPH at 340 nm by spectrophotometry in a 24 well plate in the presence of Acetyl-CoA, Malonyl-CoA, and NADPH. To assess the impact of SNP induced amino acid changes in FASN protein structure, in-silico simulations were performed. Our results indicated that FASN g.17924A&gt;G SNP induces a change in the enzyme activity in subcutaneous adipose tissue, which is higher when the AA genotype is present and lower in the presence of the AG genotype. The in-silico analysis of the amino acid substitution shows that there was a structural change in the dimeric form of the protein between genotypes. Moreover, the global energy between subunits is lower and more favorable when the AA genotype is present and higher and less favorable for the AG genotype. It was also found that the fatty acid profile of subcutaneous adipose tissue was affected when the AG genotype was present, decreasing the C16:0 fatty acid levels and increasing the C18:0 fatty acid levels. The FASN g.17924A&gt;G SNP alters the FASN enzyme structure and activity, leading to a variation in the fatty acid composition of subcutaneous adipose tissue in Holstein Friesian steers. Implications: This SNP could be considered as a tool to improve the fat deposition or marbling and the fatty acid profile in cattle.

Body composition, mineral metabolism, and endocrine function of adipose tissue: influence of a nutritional supplement of propolis

Introduction: propolis and its components influence lipid metabolism; however, its effect on body composition and mineral metabolism remains unknown. Objectives: to determine the effect of natural propolis supplementation on body composition, mineral metabolism, and the endocrine function of adipose tissue. Material and methods: twenty albino male Wistar rats (8 weeks old) were divided into two groups of 10 animals each. The rats were fed two different types of diet for 90 days: a standard diet for the control group (group C) and the same standard diet + 2 % propolis (group P). Thyroid hormones, ghrelin, leptin, adiponectin and insulin, non-esterified fatty acids (NEFA) in plasma, body composition (lean mass, fat mass and body water), and mineral deposition in target organs (spleen, brain, heart, lungs, testicles, kidneys and femur) were assessed. Results: thyroid stimulating hormone (TSH), triiodothyronine (T3) and thyroxine (T4) did not show any differences after supplementation with propolis, while ghrelin and adiponectin decreased (p < 0.01 and p < 0.05, respectively) and insulin (p < 0.01), leptin (p < 0.05) and NEFA (p < 0.05) increased when 2 % propolis was supplied, while weight and body fat were reduced (p < 0.05) and lean mass increased. Lastly, the propolis supplement improves calcium deposition in the spleen, lungs, testes, and femur (p < 0.05). Conclusion: propolis supplementation of the diet (2 %) causes a decrease in the secretion of ghrelin and adiponectin, increasing the release of non-esterified fatty acids and the rate of insulin secretion. In addition, propolis supplementation induces an improvement in calcium deposition in target organs without affecting the rest of minerals, which improves body composition by inducing a reduction in weight and visceral adipose tissue, and improvement in lean mass.

The effect of immunocastration on adipose tissue deposition and composition in pigs

Immunocastrated pigs (IC) exhibit intensive fat deposition after immunisation, but the underlying mechanisms of intensified fat metabolism and deposition are not yet fully understood. Moreover, there is also a lack of comparative studies performed on IC, entire males (EM) and surgical castrates (SC). The main objective of our research was, therefore, to characterise the adipose tissue from the quantitative, histo-morphological and biochemical perspectives in IC 5 weeks after their immunisation in comparison to EM and SC. Immunocastrated pigs had an intermediate position in carcass fatness traits between EM (the leanest) and SC (the fattest). The histo-morphological traits of the subcutaneous adipose tissue of IC were similar to those of SC and differed from those of EM; i.e., they exhibited larger adipocytes in the outer backfat and a larger lobulus surface area in both backfat layers than EM. Intensive fat tissue development in IC was corroborated with higher activities of lipogenic enzymes (i.e., fatty acid synthase, malic enzyme, glucose 6-phosphate dehydrogenase, citrate cleavage enzyme), which was especially pronounced in the subcutaneous adipose tissue of IC (1.5- to 2.7-fold higher activity than in EM or SC). The fatty acid composition of the backfat in IC was similar to that in EM pigs. Both IC and EM exhibited less saturated and more polyunsaturated fatty acids than SC. In contrast, the fatty acid composition of the intramuscular fat of longissimus dorsi muscle in IC pigs was more similar to SC than to EM (higher monounsaturated and lower polyunsaturated fatty acid content in IC and SC than EM). In this study, it was demonstrated that immunocastration notably influenced lipid metabolism. This was shown by increased quantity of lipid depots and with changes in adipose tissue cellularity compared to EM, with changes in the fatty acid composition of the intramuscular fat and enhanced lipogenic activity compared to both EM and SC. These results provide new insights into the specificity of adipose tissue development and deposition in IC compared to EM and SC.

The application of in utero magnetic resonance imaging in the study of the metabolic and cardiovascular consequences of the developmental origins of health and disease.

Observing fetal development in utero is vital to further the understanding of later-life diseases. Magnetic resonance imaging (MRI) offers a tool for obtaining a wealth of information about fetal growth, development, and programming not previously available using other methods. This review provides an overview of MRI techniques used to investigate the metabolic and cardiovascular consequences of the developmental origins of health and disease (DOHaD) hypothesis. These methods add to the understanding of the developing fetus by examining fetal growth and organ development, adipose tissue and body composition, fetal oximetry, placental microstructure, diffusion, perfusion, flow, and metabolism. MRI assessment of fetal growth, organ development, metabolism, and the amount of fetal adipose tissue could give early indicators of abnormal fetal development. Noninvasive fetal oximetry can accurately measure placental and fetal oxygenation, which improves current knowledge on placental function. Additionally, measuring deficiencies in the placenta’s transport of nutrients and oxygen is critical for optimizing treatment. Overall, the detailed structural and functional information provided by MRI is valuable in guiding future investigations of DOHaD.

Fatty acid concentration of plasma, muscle, adipose and liver from beef heifers fed an encapsulated n-3 polyunsaturated fatty acid supplement

Increasing the content of polyunsaturated fat in the human diet is a priority for reducing cardiovascular disease and cancer risks. Beef has the potential to contribute to the polyunsaturated fat content in the human diet; however, ruminants cannot synthesise many long-chain fatty acids de novo; they require dietary supplementation. The objectives of the current study were to evaluate (i) the effect of a partially rumen protected n-3 long-chain polyunsaturated fatty acid (LC-PUFA) dietary supplement on the fatty acid composition of muscle (Longissimus dorsi), adipose and liver tissues of beef heifers and (ii) the usefulness of blood plasma as a predictor of tissue concentrations of specific fatty acids. Charolais crossbred heifers (n = 20) were assigned to one of two isolipid dietary treatments namely palmitic acid (control) or an n-3 LC-PUFA supplement for a 91-day period. Blood plasma and adipose tissue samples were taken to determine the temporal effect of these diets on fatty acid composition (days 0, 10, 35 and 91), while liver and muscle samples were taken following slaughter. Dietary lipid source did not influence animal growth rate or body condition score. At day 91, the percentage differences between control and n-3 LC-PUFA heifers in concentrations of eicosapentaenoic acid were +61, +176 and +133 % in liver, muscle and adipose, respectively. For docosahexaenoic acid, at the same time point, the percentage differences were +57, +73 and +138 % for liver, muscle and adipose, respectively. Medium-to-strong positive correlation coefficients were evident for liver and plasma fatty acids, in particular, there were positive relationships with concentrations of total saturated fatty acid (SFA), total n-6 PUFA and total n-3 PUFA. This trend also extended to both the ratio of PUFA to SFA (slope (β1) = 0.56 ± 0.167, intercept (β0) = 0.56, R2 = 0.61, P < 0.05) and the ratio of n-6 to n-3 PUFA (β1 = 0.15 ± 0.054, β0 = 0.24, R2 = 0.52, P < 0.05). A strong correlation was also detected in the ratio of n-6 to n-3 in plasma and muscle tissue of heifers fed the n-3 LC-PUFA diet (β1 = 0.53 ± 0.089, β0 = −0.31, R2 = 0.83, P < 0.001). The results of this study show that the n-3 LC-PUFA can be readily increased through targeted supplementation and that plasma concentrations of n-3 LC-PUFA are useful predictors of their concentrations in a number of economically important tissues.

Tissue-specific fatty acid composition, cellularity, and gene expression in diverse cattle breeds

The nutritional quality of beef relates to the fatty acid (FA) composition of bovine adipose tissue. Those molecular mechanisms that induce the differing amounts and composition of fat in cattle breeds according to age at maturity and purpose of production remain unclear. Therefore, this study investigated the composition of total FAs, adipocyte size, and expression of some key genes involved in several adipogenesis and lipogenesis pathways measured in distinct adipose tissue depots from bulls of the genetically diverse cattle breeds Aberdeen Angus (n = 9), Gascon (n = 10), Holstein (n = 9), and Fleckvieh (n = 10). The animals were finished under identical housing and feeding conditions until slaughter at a similar age of 17 months. After slaughter, cod adipose tissue (CAT), subcutaneous adipose tissue (SAT), and M. longissimus lumborum (MLL) samples were collected. The saturated FA proportions were higher (P < .01) in CAT than in SAT across all breeds, whereas monounsaturated FA proportions were consistently higher (P < .001) in SAT compared to CAT and MLL. Aberdeen Angus bulls were distinguished from the other breeds in the proportions of mostly de novo synthesized C14:0, C16:0, C14:1n-5, C16:1n-7, and conjugated linoleic acid (P < .05). Adipocyte size decreased in the order CAT > SAT > MLL, and the largest adipocytes were observed in CAT of Holstein bulls (P < .05). Gene expression differences were more pronounced between adipose tissue depots than between breeds. The expression levels of ACACA, FASN, and SCD1 genes were related to tissue-specific, and to a lesser extent also breed-specific, differences in FA composition.

Effect of production system on fatty acid composition in subcutaneous adipose tissue of Ile de France lambs

Effect of production system on fatty acid composition in subcutaneous adipose tissue of Ile de France lambs