Short-term fatty acid intervention elicits differential gene expression responses in adipose tissue from lean and overweight men

Differences in fatty acid profiles and desaturation indices of abdominal subcutaneous adipose tissue between pregnant women with and without PCOS

The objective was to determine the differences in fatty acid (FA) profiles in subcutaneous adipose tissue (AT) between pregnant women with polycystic ovary syndrome (PCOS) and those without PCOS. FA profiles of AT samples from 13 PCOS and 32 non-PCOS, all of whom underwent caesarean section were compared using gas chromatography. Age and BMI in the two groups were similar. Twenty-one FAs were detected and the total saturated FA percentage of experimental groups was similar. While the total monounsaturated FA (MUFA) (p < 0.0004) and desaturase index (18:1 cis-9/18:0; p < 0.03) were higher in PCOS women than non-PCOS women, total polyunsaturated FA (PUFA) was lower in PCOS than non-PCOS women (p < 0.004). Docosahexaenoic acid level of the two groups was similar while α-linolenic acid and eicosapentaenoic acid levels were significantly (p < 0.05) lower in PCOS. Total trans-FA, C18:1 t9 and C18:2t were lower in PCOS women (p < 0.05). These results indicate differences in desaturase index, MUFA and PUFA, especially n-3 FA in AT between age and BMI-matched pregnant PCOS and non-PCOS pregnant subjects. Further studies are warranted to replicate these findings and to investigate potential changes in these profiles in non-pregnant PCOS women.

Effect of 8-week of dietary micronutrient supplementation on gene expression in elite handball athletes

Purpose

A study was made of the changes in gene expression in elite handball athletes, comparing gene modulation before, after and in the absence of an 8-week nutritional intervention with multivitamin/mineral supplements.

Methods

Thirteen elite handball athletes (aged 22.9 ± 2.7 years) and 13 sedentary controls (aged 20.9 ± 2.8 years) were included. Three timepoints were established: T0 (baseline conditions); T8 (after 8 weeks of supplementation with a multivitamin/mineral complex); and T16 (after 8 weeks in the absence of supplementation). The expressions of a total 112 of genes were evaluated by RT-qPCR analysis with the QuantStudioTM 12K Flex Real-Time PCR System.

Results

The analysis revealed different gene regulation profiles of genes implicated in cell communication, cell energy metabolism, inflammation and the immune system, oxidative stress and muscle function in athletes compared to sedentary controls under resting conditions (upregulated genes: effect size = large, ƞ2 = 1.011 to 1.398, p < 0.05; downregulated genes: effect size = large, ƞ2 = 0.846 and 1.070, p < 0.05, respectively). The nutritional intervention encouraged gene upregulation in elite athletes (p < 0.05). In a follow-up investigation, the IRAK1, CD81, ITGB1, ACADS PDHA2 and GPX1 genes were downregulated in athletes, with a moderate main effect for time-by-group interaction (ηP2 = 0.099 to 0.133; p < 0.05). Additionally, nutritional genes such as MTHFR and THTPA revealed a moderate effect over all the timepoints and group interaction in the study (ηP2 = 0.070 to 0.092; p < 0.05).

Conclusions

Elite handball athletes showed a different expression profile in reference to key genes implicated in several sports performance-related functions compared to the sedentary controls, in addition to modulation of gene expression after multivitamin/mineral supplementation.

White adipose tissue reference network: a knowledge resource for exploring health-relevant relations

Optimal health is maintained by interaction of multiple intrinsic and environmental factors at different levels of complexity—from molecular, to physiological, to social. Understanding and quantification of these interactions will aid design of successful health interventions. We introduce the reference network concept as a platform for multi-level exploration of biological relations relevant for metabolic health, by integration and mining of biological interactions derived from public resources and context-specific experimental data. A White Adipose Tissue Health Reference Network (WATRefNet) was constructed as a resource for discovery and prioritization of mechanism-based biomarkers for white adipose tissue (WAT) health status and the effect of food and drug compounds on WAT health status. The WATRefNet (6,797 nodes and 32,171 edges) is based on (1) experimental data obtained from 10 studies addressing different adiposity states, (2) seven public knowledge bases of molecular interactions, (3) expert’s definitions of five physiologically relevant processes key to WAT health, namely WAT expandability, Oxidative capacity, Metabolic state, Oxidative stress and Tissue inflammation, and (4) a collection of relevant biomarkers of these processes identified by BIOCLAIMS (http://bioclaims.uib.es). The WATRefNet comprehends multiple layers of biological complexity as it contains various types of nodes and edges that represent different biological levels and interactions. We have validated the reference network by showing overrepresentation with anti-obesity drug targets, pathology-associated genes and differentially expressed genes from an external disease model dataset. The resulting network has been used to extract subnetworks specific to the above-mentioned expert-defined physiological processes. Each of these process-specific signatures represents a mechanistically supported composite biomarker for assessing and quantifying the effect of interventions on a physiological aspect that determines WAT health status. Following this principle, five anti-diabetic drug interventions and one diet intervention were scored for the match of their expression signature to the five biomarker signatures derived from the WATRefNet. This confirmed previous observations of successful intervention by dietary lifestyle and revealed WAT-specific effects of drug interventions. The WATRefNet represents a sustainable knowledge resource for extraction of relevant relationships such as mechanisms of action, nutrient intervention targets and biomarkers and for assessment of health effects for support of health claims made on food products.

Dietary energy source largely affects tissue fatty acid composition but has minor influence on gene transcription in Iberian pigs

A trial was performed to compare the effects of different dietary sources of MUFA on the fatty acid (FA) composition, lipid metabolism, and gene transcription in different tissues of Iberian pigs. Twenty-seven Iberian male pigs of 28 kg live weight (LW) were divided in 2 groups and fed with 1 of 2 isocaloric diets: a standard diet with carbohydrates as energy source (CH) and a diet enriched with high-oleic sunflower oil (HO). Ham adipose tissue was sampled by biopsy at 44 and 70 kg LW. At 110 kg LW pigs were slaughtered and backfat, loin, and liver tissues were sampled. Animals of the HO group showed higher MUFA content and lower SFA in all the analyzed tissues (P < 0.001). These main effects were established early during the treatment and increased only slightly along time. Small diet effects were also detected on PUFA, which showed differences according to sampling time, tissue, and lipid fraction. Effects of diet on gene expression were explored with a combined approach analyzing adipose tissue transcriptome and quantifying the expression of a panel of key genes implicated in lipogenesis and lipid metabolism processes in backfat, muscle, and liver. Backfat transcriptome showed small effects of diet on gene expression, in number and magnitude. According to the posterior probabilities (PP) of the probe-specific expression differences between dietary groups (PP < 0.01), 37 genes were considered differentially expressed (DE). Gene ontology allowed relating them with several biological functions including lipid metabolic processes. Quantitative PCR confirmed several DE genes in adipose tissue (RXRG, LEP, and ME1; P < 0.0001, P < 0.05, and P < 0.0001, respectively), but no DE gene was found in loin or liver tissues. Joint results agree with a metabolic adjustment of adipose tissue FA levels by the subtle effect of the diet on the regulation of several lipid metabolism pathways, mainly FA oxidation and prostanoid synthesis, with LEP, RXRG, and PTGS2 genes playing mayor roles.

Coordinated and interactive expression of genes of lipid metabolism and inflammation in adipose tissue and liver during metabolic overload

Background

Chronic metabolic overload results in lipid accumulation and subsequent inflammation in white adipose tissue (WAT), often accompanied by non-alcoholic fatty liver disease (NAFLD). In response to metabolic overload, the expression of genes involved in lipid metabolism and inflammatory processes is adapted. However, it still remains unknown how these adaptations in gene expression in expanding WAT and liver are orchestrated and whether they are interrelated.

Methodology/Principal Findings

ApoE*3Leiden mice were fed HFD or chow for different periods up to 12 weeks. Gene expression in WAT and liver over time was evaluated by micro-array analysis. WAT hypertrophy and inflammation were analyzed histologically. Bayesian hierarchical cluster analysis of dynamic WAT gene expression identified groups of genes (‘clusters’) with comparable expression patterns over time. HFD evoked an immediate response of five clusters of ‘lipid metabolism’ genes in WAT, which did not further change thereafter. At a later time point (>6 weeks), inflammatory clusters were induced. Promoter analysis of clustered genes resulted in specific key regulators which may orchestrate the metabolic and inflammatory responses in WAT. Some master regulators played a dual role in control of metabolism and inflammation. When WAT inflammation developed (>6 weeks), genes of lipid metabolism and inflammation were also affected in corresponding livers. These hepatic gene expression changes and the underlying transcriptional responses in particular, were remarkably similar to those detected in WAT.

Conclusion

In WAT, metabolic overload induced an immediate, stable response on clusters of lipid metabolism genes and induced inflammatory genes later in time. Both processes may be controlled and interlinked by specific transcriptional regulators. When WAT inflammation began, the hepatic response to HFD resembled that in WAT. In all, WAT and liver respond to metabolic overload by adaptations in expression of gene clusters that control lipid metabolism and inflammatory processes in an orchestrated and interrelated manner.

Nutrigenomics approach elucidates health-promoting effects of high vegetable intake in lean and obese men

We aimed to explore whether vegetable consumption according to guidelines has beneficial health effects determined with classical biomarkers and nutrigenomics technologies. Fifteen lean (age 36 ± 7 years; BMI 23.4 ± 1.7 kg m⁻²) and 17 obese (age 40 ± 6 years; BMI 30.3 ± 2.4 kg m⁻²) men consumed 50- or 200-g vegetables for 4 weeks in a randomized, crossover trial. Afterward, all subjects underwent 4 weeks of energy restriction (60 % of normal energy intake). Despite the limited weight loss of 1.7 ± 2.4 kg for the lean and 2.1 ± 1.9 kg for the obese due to energy restriction, beneficial health effects were found, including lower total cholesterol, LDL cholesterol and HbA1c concentrations. The high vegetable intake resulted in increased levels of plasma amino acid metabolites, decreased levels of 9-HODE and prostaglandin D3 and decreased levels of ASAT and ALP compared to low vegetable intake. Adipose tissue gene expression changes in response to vegetable intake were identified, and sets of selected genes were submitted to network analysis. The network of inflammation genes illustrated a central role for NFkB in (adipose tissue) modulation of inflammation by increased vegetable intake, in lean as well as obese subjects. In obese subjects, high vegetable intake also resulted in changes related to energy metabolism, adhesion and inflammation. By inclusion of sensitive omics technologies and comparing the changes induced by high vegetable intake with changes induced by energy restriction, it has been shown that part of vegetables’ health benefits are mediated by changes in energy metabolism, inflammatory processes and oxidative stress.

Postprandial blood cell transcriptomics in response to the ingestion of dairy products by healthy individuals

The aim of this intervention study was to measure genome-wide postprandial gene expression in human blood cells after the ingestion of a single serving of milk, to identify the downstream physiological processes regulated by the differentially expressed genes, and to use this gene expression signature as a reference to compare it with the response following the ingestion of a transformed dairy product, namely, yogurt. We conducted a randomized, controlled, single-blinded, crossover study on six healthy male individuals. After an overnight fast, 540 g of milk or yogurt was ingested by the subjects. Blood samples were collected before (0 h) and after (2 h/4 h/6 h) ingestion, and the blood cell transcriptome was analyzed using a linear kinetic analysis that increases the statistical power of the study. The differentially expressed transcripts identified after the ingestion of milk (575 transcripts) and yogurt (625 transcripts) modulated similar biological processes. In particular, genes involved in protein biosynthesis and mitochondrial activities followed biphasic kinetics being down-regulated at 2 h and more pronouncedly up-regulated at 6 h. The opposite kinetics were observed for inflammatory and apoptotic processes during the same time frame. The human blood cell transcriptome appeared to be specifically modulated by specific nutrients present in bovine milk, a property that was further modified when milk was fermented to yogurt. The coordinated changes in postprandial expression of genes involved in basic biological processes suggest that postprandial blood cell transcriptomics may allow insight into the nutritional effects of selected foods in the prevention or development of chronic metabolic and inflammatory disorders.

Soy food supplementation, dietary fat reduction and peripheral blood gene expression in postmenopausal women--a randomized, controlled trial

SCOPE

The effect of soy food supplementation or dietary fat reduction on gene expression is not well studied.

METHODS AND RESULTS

We evaluated the potential of gene expression profiling in peripheral blood mononuclear cells (PBMCs) collected at baseline and at the completion of an 8-wk controlled dietary intervention. Healthy postmenopausal women were randomized to a very-low-fat diet (VLFD; 11% of energy as fat) (n=21), a Step 1 diet (25% energy as fat) supplemented with soy food (SFD; 50 mg isoflavones per day) (n=20), or a control Step 1 diet (CD; 27% energy as fat) with no SFD (n=18). All diets were prepared at the General Clinical Research Center of the University of Southern California. We did not observe any gene that showed variable response across the three dietary interventions. However, there were notable changes in gene expression associated with the intervention in the VLFD and SFD groups. Our findings suggest that the expression of nicotinamide phosphoribosyltransferase (NAMPT) and genes related to Fc γ R-mediated phagocytosis and cytokine interactions may be significantly altered in association with dietary fat reduction and soy supplementation. Gene expression changes in NAMPT were somewhat dampened with adjustment for weight but changes related to Fc γ R-mediated phagocytosis and cytokine interactions remained largely unchanged.

CONCLUSION

PBMCs can reveal novel gene expression changes in association with controlled dietary intervention.

An antiinflammatory dietary mix modulates inflammation and oxidative and metabolic stress in overweight men: a nutrigenomics approach

BACKGROUND

Low-grade chronic inflammation in overweight subjects is thought to play an important role in disease development.

OBJECTIVE

It was hypothesized that specific dietary components are able to reduce low-grade inflammation as well as metabolic and oxidative stress.

DESIGN

Dietary products [resveratrol, green tea extract, alpha-tocopherol, vitamin C, n-3 (omega-3) polyunsaturated fatty acids, and tomato extract] selected for their evidence-based antiinflammatory properties were combined and given as supplements to 36 healthy overweight men with mildly elevated plasma C-reactive protein concentrations in a double-blind, placebo-controlled, crossover study with treatment periods of 5 wk. Inflammatory and oxidative stress defense markers were quantified in plasma and urine. Furthermore, 120 plasma proteins, 274 plasma metabolites (lipids, free fatty acids, and polar compounds), and the transcriptomes of peripheral blood mononuclear cells and adipose tissue were quantified.

RESULTS

Plasma adiponectin concentrations increased by 7%, whereas C-reactive protein (principal inflammation marker) was unchanged. However, a multitude of subtle changes were detected by an integrated analysis of the "omics" data, which indicated modulated inflammation of adipose tissue, improved endothelial function, affected oxidative stress, and increased liver fatty acid oxidation.

CONCLUSION

An intervention with selected dietary products affected inflammatory processes, oxidative stress, and metabolism in humans, as shown by large-scale profiling of genes, proteins, and metabolites in plasma, urine, and adipose tissue. This trial was registered at clinical trials.gov as NCT00655798.

Conjugated linoleic acids as functional food: an insight into their health benefits

This review evaluates the health benefits of the functional food, conjugated linoleic acids (CLA) - a heterogeneous group of positional and geometric isomers of linoleic acid predominantly found in milk, milk products, meat and meat products of ruminants. During the past couple of decades, hundreds of reports - principally based on in vitro, microbial, animal, and of late clinical trials on humans - have been accumulating with varying biological activities of CLA isomers. These studies highlight that CLA, apart form the classical nuclear transcription factors-mediated mechanism of action, appear to exhibit a number of inter-dependent molecular signalling pathways accounting for their reported health benefits. Such benefits relate to anti-obesitic, anti-carcinogenic, anti-atherogenic, anti-diabetagenic, immunomodulatory, apoptotic and osteosynthetic effects. On the other hand, negative effects of CLA have been reported such as fatty liver and spleen, induction of colon carcinogenesis and hyperproinsulinaemia. As far as human consumption is concerned, a definite conclusion for CLA safety has not been reached yet. Parameters such as administration of the type of CLA isomer and/or their combination with other polyunsaturated fatty acids, mode of administration (eg., as free fatty acid or its triglyceride form, liquid or solid), daily dose and duration of consumption, gender, age, or ethnic and geographical backgrounds remain to be determined. Yet, it appears from trials so far conducted that CLA are functional food having prevailing beneficial health effects for humans.