Differential Expression of Oxidative Stress and Inflammation Related Genes in Peripheral Blood Mononuclear Cells in Response to a Low-Calorie Diet: A Nutrigenomics Study

Molecular nutrition research: the modern way of performing nutritional science

In spite of amazing progress in food supply and nutritional science, and a striking increase in life expectancy of approximately 2.5 months per year in many countries during the previous 150 years, modern nutritional research has a great potential of still contributing to improved health for future generations, granted that the revolutions in molecular and systems technologies are applied to nutritional questions. Descriptive and mechanistic studies using state of the art epidemiology, food intake registration, genomics with single nucleotide polymorphisms (SNPs) and epigenomics, transcriptomics, proteomics, metabolomics, advanced biostatistics, imaging, calorimetry, cell biology, challenge tests (meals, exercise, etc.), and integration of all data by systems biology, will provide insight on a much higher level than today in a field we may name molecular nutrition research. To take advantage of all the new technologies scientists should develop international collaboration and gather data in large open access databases like the suggested Nutritional Phenotype database (dbNP). This collaboration will promote standardization of procedures (SOP), and provide a possibility to use collected data in future research projects. The ultimate goals of future nutritional research are to understand the detailed mechanisms of action for how nutrients/foods interact with the body and thereby enhance health and treat diet-related diseases.

VNN1 gene expression levels and the G-137T polymorphism are associated with HDL-C levels in Mexican prepubertal children

BACKGROUND

VNN1 gene expression levels and the G-137T polymorphism have been associated with high density lipoprotein cholesterol (HDL-C) levels in Mexican American adults. We aim to evaluate the contribution of VNN1 gene expression and the G-137T variant to HDL-C levels and other metabolic traits in Mexican prepubertal children.

METHODOLOGY/PRINCIPAL FINDINGS

VNN1 mRNA expression levels were quantified in peripheral blood leukocytes from 224 unrelated Mexican-Mestizo children aged 6-8 years (107 boys and 117 girls) and were genotyped for the G-137T variant (rs4897612). To account for population stratification, a panel of 10 ancestry informative markers was analyzed. After adjustment for admixture, the TT genotype was significantly associated with lower VNN1 mRNA expression levels (P = 2.9 × 10(-5)), decreased HDL-C levels (β = -6.19, P = 0.028) and with higher body mass index (BMI) z-score (β = 0.48, P = 0.024) in the total sample. In addition, VNN1 expression showed a positive correlation with HDL-C levels (r = 0.220; P = 0.017) and a negative correlation with BMI z-score (r = -0.225; P = 0.015) only in girls.

CONCLUSION/SIGNIFICANCE

Our data suggest that VNN1 gene expression and the G-137T variant are associated with HDL-C levels in Mexican children, particularly in prepubertal girls.

Effects of yeast cell wall-derived mannan-oligosaccharides on jejunal gene expression in young broiler chickens

The use of mannan-oligosaccharides (MOS) as alternatives to antibiotic growth promoters (AGP) has gained in popularity in recent years due to regulatory restrictions of using AGP in food animal production. Benefits of MOS usage include improvement on animal performance, feed efficiency, and gastrointestinal health. The molecular mechanisms of these functions however are not clear. The goal of the current study was to use a transcriptomics approach to investigate the effects of MOS on the intestinal gene expression profile of young broilers and characterize biological gene pathways responsible for the actions of MOS. One hundred and twenty 1-d-old Cobb 500 broiler chicks were randomly divided into 2 groups and were fed either a standard wheat-soybean meal-based (control) diet or the same diet supplemented with 2.2 g/kg of MOS (Bio-Mos, Alltech, Nicholasville, KY) for 3 wk, followed by jejunal gene expression profiling analysis using chicken-specific Affymetrix microarrays. Results indicated that a total of 672 genes were differentially expressed (P < 0.01 and fold change >1.2) in the jejunum by MOS supplementation. Association analysis indicated that differentially expressed genes are involved in diverse biological functions including energy production, cell death, and protein translation. Expression of 77 protein synthesis-related genes was differentially regulated by MOS in the jejunum. Further pathway analysis indicated that 15 genes related to oxidative phosphorylation were upregulated in the jejunum, and expression of genes important in cellular stress response, such as peroxiredoxin 1, superoxide dismutase 1, and thioredoxin, were also increased by MOS. Differential expression of genes associated with cellular immune processes, including lysozyme, lumican, β 2-microglobin, apolipoprotein A-1, and fibronectin 1, were also observed in MOS-fed broilers. In summary, this study systematically identified biological functions and gene pathways that are important in mediating the biological effects of MOS in broilers.

Gene expression of peripheral blood mononuclear cells as a tool in dietary intervention studies: What do we know so far?

Peripheral blood mononuclear cells (PBMCs) generally refer to monocytes and lymphocytes, representing cells of the innate and adaptive immune systems. PBMCs are a promising target tissue in the field of nutrigenomics because they seem to reflect the effects of dietary modifications at the level of gene expression. In this review, we describe and discuss the scientific literature concerning the use of gene expression at the mRNA level measured from PBMCs in dietary interventions studies conducted in humans. A search of literature was undertaken using PubMed (last assessed November 24, 2011) and 20 articles were selected for discussion. Currently, results from these studies showed that PBMCs seem to reflect liver environment and complement adipose tissue findings in transcriptomics. PBMC gene expression after dietary intervention studies can be used for studying the response of certain genes related to fatty acid and cholesterol metabolism, and to explore the response of dietary interventions in relation to inflammation. However, PBMC transcriptomics from dietary intervention studies have not resulted yet in clear confirmation of candidate genes related to disease risk. Use of microarray technology in larger well-designed dietary intervention studies is still needed for exploring PBMC potential in the field of nutrigenomics.

Relationship between advanced oxidation protein products, advanced glycation end products, and S-nitrosylated proteins with biological risk and MDR-1 polymorphisms in patients affected by B-chronic lymphocytic leukemia

The aim of our study was to analyze the serum levels of advanced oxidation protein products (AOPPs) and advanced glycation end products (AGEs), and protein nitrosylation in patients with B-chronic lymphocytic leukemia (B-CLL). AOPPs, AGEs, and S-nitrosylated were increased in B-CLL patients. The mutation of IgVH gene, CD 38, and Zap 70 expression were not associated with increased oxidative stress. The mutant 2677GT genotype was found to be associated with higher AGEs levels with respect to wild-type genotype, while as far the C3435T MDR1 polymorphism is concerned, subjects presenting wild-type genotype showed higher values of AOPPs with respect to heterozygous genotype. Our results suggest that B-CLL is associated with oxidative stress.

Nutrigenomics and personalized diets: What will they mean for food?

The modern food system feeds six billion people with remarkable diversity, safety, and nutrition. Yet, the current rise in diet-related diseases is compromising health and devaluing many aspects of modern agriculture. Steps to increase the nutritional quality of individual foods will assist in personalizing health and in guiding individuals to achieve superior health. Nutrigenomics is the scientific field of the genetic basis for varying susceptibilities to disease and the diverse responses to foods. Although some of these genetic determinants will be simple and amenable to personal genotyping as the means to predict health, in practice most will not. As a result, genotyping will not be the secret to personalizing diet and health. Human assessment technologies from imaging to proteomics and metabolomics are providing tools to both understand and accurately assess the nutritional phenotype of individuals. The business models are also emerging to bring these assessment capabilities to industrial practice, in which consumers will know more about their personal health and seek personal solutions.

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.

Caloric restriction and chronic inflammatory diseases

A reduction in calorie intake [caloric restriction (CR)] appears to consistently decrease the biological rate of aging in a variety of organisms as well as protect against age-associated diseases including chronic inflammatory disorders such as cardiovascular disease and diabetes. Although the mechanisms behind this observation are not fully understood, identification of the main metabolic pathways affected by CR has generated interest in finding molecular targets that could be modulated by CR mimetics. This review describes the general concepts of CR and CR mimetics as well as discusses evidence related to their effects on inflammation and chronic inflammatory disorders. Additionally, emerging evidence related to the effects of CR on periodontal disease in non-human primates is presented. While the implementation of this type of dietary intervention appears to be challenging in our modern society where obesity is a major public health problem, CR mimetics could offer a promising alternative to control and perhaps prevent several chronic inflammatory disorders including periodontal disease.

Balanced caloric macronutrient composition downregulates immunological gene expression in human blood cells-adipose tissue diverges

Cardiovascular disease, obesity, and type 2 diabetes are conditions characterized by low-grade systemic inflammation, strongly influenced by lifestyle, but the mechanisms that link these characteristics are poorly understood. Our first objective was to investigate if a normocaloric diet with a calorically balanced macronutrient composition influenced immunological gene expression. Findings regarding the suitability of blood as biological material in nutrigenomics and gene expression profiling have been inconclusive. Our second objective was to compare blood and adipose tissue sample quality in terms of adequacy for DNA-microarray analyses, and to determine tissue-specific gene expression patterns. Blood and adipose tissue samples were collected for gene expression profiling from three obese men before, during, and after a 28-day normocaloric diet intervention where each meal contained an approximately equal caloric load of macronutrients. Time series analyses of blood gene expression revealed a cluster of downregulated genes involved in immunological processes. Blood RNA quality and yield were satisfactory, and DNA-microarray analysis reproducibility was similar in blood and adipose tissue. Gene expression correlation between blood and adipose tissue varied according to gene function, and was especially low for genes involved in immunological and metabolic processes. This suggests that diet composition is of importance in inflammatory processes in blood cells. The findings also suggest that a systems biology approach, in which tissues are studied in parallel, should be employed to fully understand the impact of dietary challenges on the human body.

A comparative transcriptomic study of vitamin E and an algae-based antioxidant as antioxidative agents: investigation of replacing vitamin E with the algae-based antioxidant in broiler diets

Previous study indicated that inclusion of an algae-based antioxidant as an antioxidative agent [EconomasE, Alltech, Nicholasville, KY; EcoE] significantly reduced the amount of vitamin E (VE) required in broiler diets without compromising performance and meat quality. To assess the mechanisms related to the VE-saving activity of EcoE, as well as other potential functions related to EcoE and VE supplementation, we analyzed gene expression profiles of breast muscle from broilers fed a control diet, the control diet + 50 IU of VE/kg, the control diet + 100 IU of VE/kg, or the control diet + 200 g of EcoE/ton. Evaluation of the serum antioxidant capacity indicated that dietary supplementation of either a high level of VE (50 or 100 IU of VE/kg) or EcoE significantly improved bird antioxidant status. Analysis of gene expression profiles indicated that expression of 542 genes of the breast muscle were altered (P < 0.05, fold change >1.2) by dietary treatments, of which a significant part were commonly regulated by EcoE and VE (especially the control diet + 50 IU of VE/kg). In addition to the process of cellular oxidation, gene ontology analysis indicated the involvement of EcoE and VE on cell morphology, skeletal and muscular system development and function, immune response, and multiple metabolic processes, including lipid, carbohydrate, and drug metabolism. Results of this experiment indicate that the biological roles of high VE, including its activity as an antioxidant, can be greatly mimicked at the transcriptional level by EcoE, and they suggest a relationship of functional redundancy between VE and EcoE in the broiler diets.

A dual epigenomic approach for the search of obesity biomarkers: DNA methylation in relation to diet-induced weight loss

Epigenetics could help to explain individual differences in weight loss after an energy-restriction intervention. Here, we identify novel potential epigenetic biomarkers of weight loss, comparing DNA methylation patterns of high and low responders to a hypocaloric diet. Twenty-five overweight or obese men participated in an 8-wk caloric restriction intervention. DNA was isolated from peripheral blood mononuclear cells and treated with bisulfite. The basal and endpoint epigenetic differences between high and low responders were analyzed by methylation microarray, which was also useful in comparing epigenetic changes due to the nutrition intervention. Subsequently, MALDI-TOF mass spectrometry was used to validate several relevant CpGs and the surrounding regions. DNA methylation levels in several CpGs located in the ATP10A and CD44 genes showed statistical baseline differences depending on the weight-loss outcome. At the treatment endpoint, DNA methylation levels of several CpGs on the WT1 promoter were statistically more methylated in the high than in the low responders. Finally, different CpG sites from WT1 and ATP10A were significantly modified as a result of the intervention. In summary, hypocaloric-diet-induced weight loss in humans could alter DNA methylation status of specific genes. Moreover, baseline DNA methylation patterns may be used as epigenetic markers that could help to predict weight loss.

Validation of the use of peripheral blood mononuclear cells as surrogate model for skeletal muscle tissue in nutrigenomic studies

Peripheral blood mononuclear cells (PBMCs) offer a significant promise for gene expression analyses as a substitute for tissues that are not easily accessible. The objective of this study was to validate the use of PBMCs for gene expression analysis as a marker of nutritional intervention as an alternative to skeletal muscle tissue (SMT) biopsies. We performed a transcriptome comparison of PBMCs versus SMT after an 8-week supplementation with n-3 polyunsaturated fatty acid (PUFA) in 16 obese and insulin-resistant subjects. Expression levels of 48,803 transcripts were assessed by the Human-6 v3 Expression BeadChips (Illumina, San Diego, CA). In SMT, 36,738 (75%) transcripts were detected, whereas 34,182 (70%) transcripts were detected in PBMCs. Further, 88% (32,341) of these transcripts were coexpressed in both tissues. Importantly, a strong correlation (r = 0.84, p < 0.0001) was observed between transcript expression levels of PBMCs and SMT after n-3 PUFA supplementation. In conclusion, PBMCs express the majority of transcripts expressed in SMT subsequent to n-3 PUFA supplementation and their expression levels are comparable. In the interest of practicalities and cost, these results support the use of PBMCs as a surrogate model for SMT gene expression in nutrigenomic studies. Further research on PBMC and SMT gene expression in response to other nutritional exposures is warranted.

Peripheral expression of inflammatory markers in overweight female adolescents and eutrophic female adolescents with a high percentage of body fat

The objective of this study was to evaluate the peripheral expression of inflammatory markers in adolescents with different nutritional status and its correlation with parameters of the metabolic syndrome. Seventy-two female postpubescent adolescents were divided into 3 groups: eutrophic (Co), eutrophic with a high body fat percentage (HBF), and overweight (OW). Data related to the parameters of the metabolic syndrome and the peripheral expression of tumour necrosis factor (TNF)-&alpha;, interleukin (IL)-6, and IL-10 were evaluated. Higher values of glycemia and insulin resistance were found in the HBF group than in the Co group. No differences related to the peripheral expression of the cytokines were found among the groups. In the HBF group, a positive correlation was observed between TNF-&alpha; and IL-6, IL-10 and the proinflammatory cytokines, and IL-6 and glycemia. In the OW group, a positive correlation was found between IL-6 and triglycerides. Adolescents with normal weight but body fat excess present a metabolic profile and body composition similar to those of overweight adolescents. This suggests that these adolescents have a risk of developing cardiovascular diseases similar to that of overweight adolescents. The positive correlation between IL-10 and TNF-&alpha; and IL-6 suggests an attempt to inhibit the production of these cytokines by IL-10.

Genetic variants in the metabolism of omega-6 and omega-3 fatty acids: their role in the determination of nutritional requirements and chronic disease risk

The tissue composition of polyunsaturated fatty acids is important to health and depends on both dietary intake and metabolism controlled by genetic polymorphisms that should be taken into consideration in the determination of nutritional requirements. Therefore at the same dietary intake of linoleic acid (LA) and alpha-linolenic acid (ALA), their respective health effects may differ due to genetic differences in metabolism. Delta-5 and delta-6 desaturases, FADS1 and FADS2, respectively, influence the serum, plasma and membrane phospholipid levels of LA, ALA and long-chain polyunsaturated fatty acids during pregnancy, lactation, and may influence an infant's IQ, atopy and coronary heart disease (CHD) risk. At low intakes of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), polymorphisms at the 5-lipoxygenase (5-LO) level increase the risk for CHD whereas polymorphisms at cyclooxgenase-2 increase the risk for prostate cancer. At high intakes of LA the risk for breast cancer increases. EPA and DHA influence gene expression. In future, intervention studies on the biological effects of LA, ALA and LC-PUFAs, and the effects of genetic variants in FADS1 and FADS2, 5-LO and cyclooxygenase-2 should be taken into consideration both in the determination of nutritional requirements and chronic disease risk. Furthermore, genome-wide association studies need to include environmental exposures and include diet in the interaction between genetic variation and disease association.

Peripheral blood mononuclear cells as a model to study the response of energy homeostasis-related genes to acute changes in feeding conditions

Peripheral blood mononuclear cells (PBMCs) are readily accessible biological material and a potential tissue source to discover novel biomarkers of response to environmental exposures including nutrition. We analyzed whether PBMCs could reflect molecular changes that take place in response to different feeding conditions in key organs/tissues involved in energy homeostasis. We studied energy balance-related genes whose expression was altered in normoweight (control) rats and in diet-induced (cafeteria) obese rats in response to ad libitum feeding, 14-h fasting, and 6-h refeeding after fasting, using whole-genome microarray analysis. In PBMCs, the expression of the genes central to energy metabolism was altered by the feeding conditions. The number of affected genes was 75 in the control rats, but only 23 in the cafeteria obese rats. Most of these genes play a role in metabolic pathways regulated by nutritional changes, such as lipid metabolism (the metabolic pathway mainly reflected in blood cells), carbohydrate metabolism, central energy metabolism, respiratory chain/mitochondrial ATPase system, and food intake regulation. Importantly, our results showed a similar behavior to that of the mesenteric white adipose tissue. In conclusion, metabolic adaptations to acute changes in feeding conditions are reflected in the expression of genes central to energy homeostasis in PBMCs of normoweight rats, while response is impaired in cafeteria obese animals. The lower number of genes affected in obese animals indicates impaired nutritional regulation. PBMCs appear as a suitable potential model to characterize metabolic adaptations to food intake and body weight maintenance in experimental animals. These findings may also inform the development of future peripheral tissue models in the emerging field of clinical nutrigenomics.

A legume-based hypocaloric diet reduces proinflammatory status and improves metabolic features in overweight/obese subjects

BACKGROUND

The nutritional composition of the dietary intake could produce specific effects on metabolic variables and inflammatory marker concentrations. This study assessed the effects of two hypocaloric diets (legume-restricted- vs. legume-based diet) on metabolic and inflammatory changes, accompanying weight loss.

METHODS

Thirty obese subjects (17 M/13F; BMI: 32.5 ± 4.5 kg/m(2); 36 ± 8 years) were randomly assigned to one of the following hypocaloric treatments (8 weeks): Calorie-restricted legume-free diet (Control: C-diet) or calorie-restricted legume-based diet (L-diet), prescribing 4 weekly different cooked-servings (160-235 g) of lentils, chickpeas, peas or beans. Body composition, blood pressure (BP), blood biochemical and inflammatory marker concentrations as well as dietary intake were measured at baseline and after the nutritional intervention.

RESULTS

The L-diet achieved a greater body weight loss, when compared to the C-diet (-7.8 ± 2.9% vs. -5.3 ± 2.7%; p = 0.024). Total and LDL cholesterol levels and systolic BP were improved only when consuming the L-diet (p < 0.05). L-diet also resulted in a significant higher reduction in C-reactive protein (CRP) and complement C3 (C3) concentrations (p < 0.05), compared to baseline and C-diet values. Interestingly, the reduction in the concentrations of CRP and C3 remained significantly higher to L-diet group, after adjusting by weight loss (p < 0.05). In addition, the reduction (%) in CRP concentrations was positively associated with decreases (%) in systolic BP and total cholesterol concentration specifically in the L-diet group, independent from weight loss (p < 0.05).

CONCLUSION

The consumption of legumes (4 servings/week) within a hypocaloric diet resulted in a specific reduction in proinflammatory markers, such as CRP and C3 and a clinically significant improvement of some metabolic features (lipid profile and BP) in overweight/ obese subjects, which were in some cases independent from weight loss.

Genetics and beyond--the transcriptome of human monocytes and disease susceptibility

Background

Variability of gene expression in human may link gene sequence variability and phenotypes; however, non-genetic variations, alone or in combination with genetics, may also influence expression traits and have a critical role in physiological and disease processes.

Methodology/Principal Findings

To get better insight into the overall variability of gene expression, we assessed the transcriptome of circulating monocytes, a key cell involved in immunity-related diseases and atherosclerosis, in 1,490 unrelated individuals and investigated its association with >675,000 SNPs and 10 common cardiovascular risk factors. Out of 12,808 expressed genes, 2,745 expression quantitative trait loci were detected (P<5.78×10⁻¹²), most of them (90%) being cis-modulated. Extensive analyses showed that associations identified by genome-wide association studies of lipids, body mass index or blood pressure were rarely compatible with a mediation by monocyte expression level at the locus. At a study-wide level (P<3.9×10⁻⁷), 1,662 expression traits (13.0%) were significantly associated with at least one risk factor. Genome-wide interaction analyses suggested that genetic variability and risk factors mostly acted additively on gene expression. Because of the structure of correlation among expression traits, the variability of risk factors could be characterized by a limited set of independent gene expressions which may have biological and clinical relevance. For example expression traits associated with cigarette smoking were more strongly associated with carotid atherosclerosis than smoking itself.

Conclusions/Significance

This study demonstrates that the monocyte transcriptome is a potent integrator of genetic and non-genetic influences of relevance for disease pathophysiology and risk assessment.

Fruit and vegetable consumption and proinflammatory gene expression from peripheral blood mononuclear cells in young adults: a translational study

BACKGROUND

Fruits and vegetables are important sources of fiber and nutrients with a recognized antioxidant capacity, which could have beneficial effects on the proinflammatory status as well as some metabolic syndrome and cardiovascular disease features. The current study assessed the potential relationships of fruit and vegetable consumption with the plasma concentrations and mRNA expression values of some proinflammatory markers in young adults.

METHODS

One-hundred and twenty healthy subjects (50 men/70 women; 20.8 +/- 2.6 y; 22.3 +/- 2.8 kg/m2) were enrolled. Experimental determinations included anthropometry, blood pressure and lifestyle features as well as blood biochemical and inflammatory measurements. The mRNA was isolated from peripheral blood mononuclear cells (PBMC) and the gene expression concerning selected inflammatory markers was assessed by quantitative real-time PCR. Nutritional intakes were estimated by a validated semi-quantitative food-frequency questionnaire.

RESULTS

The highest tertile of energy-adjusted fruit and vegetable consumption (>660 g/d) was associated with lower plasma concentrations of C-reactive protein (CRP) and homocysteine and with lower ICAM1, IL1R1, IL6, TNFalpha and NFkappaB1 gene expression in PBMC (P for trend < 0.05), independently of gender, age, energy intake, physical activity, smoking, body mass index, systolic blood pressure and circulating non-esterified fatty acids. In addition, plasma CRP, homocysteine and TNFalpha concentrations and ICAM1, TNFalpha and NFkappaB1 gene expression in PBMC showed a descending trend as increased fiber intake (>19.5 g/d) from fruits and vegetables (P for trend < 0.05). Furthermore, the participants within the higher tertile (>11.8 mmol/d) of dietary total antioxidant capacity showed lower plasma CRP and mRNA values of ICAM1, IL1R1, IL6, TNFalpha and NFkappaB1 genes (P for trend < 0.05). The inverse association between fruit and vegetable consumption and study proinflammatory markers followed the same trend and remained statistically significant, after the inclusion of other foods/nutrients in the linear regression models.

CONCLUSION

A higher fruit and vegetable consumption was independently associated not only with reduced CRP and homocysteine concentrations but also with a lower mRNA expression in PBMC of some relevant proinflammatory markers in healthy young adults.

Nutritional genomics era: opportunities toward a genome-tailored nutritional regimen

There is increasing evidence indicating that nutritional genomics represents a promise to improve public health. This goal will be reached by highlighting the mechanisms through which diet can reduce the risk of monogenic and common polygenic diseases. Indeed, nutrition is a very relevant environmental factor involved in the development and progression of metabolic disorders, as well as other kind of diseases. The revolutionary changes in the field of genomics have led to the development and implementation of new technologies and molecular tools. These technologies have a useful application in the nutritional sciences, since they allow a more precise and accurate analysis of biochemical alterations, in addition to filling fundamental gaps in the knowledge of nutrient-genome interactions in both health and disease. Overall, these advances will open undiscovered ways in genome-customized diets for disease prevention and therapy. This review summarizes the recent knowledge concerning this novel nutritional approach, paying attention to the human genome variations, such as single-nucleotide polymorphisms and copy number variations, gene expression and innovative molecular tools to reveal them.

Time-dependent regulation of muscle caveolin activation and insulin signalling in response to high-fat diet

We studied the effect of high-fat diet on the expression and activation of the three caveolins in rat skeletal muscle and their association with the insulin signalling cascade. Initial response was characterized by increased signalling through Cav-1 and Cav-3 phosphorylation, suggesting that both participate in an initial acute response to the calorie surplus. Afterwards, Cav-1 signalling was slightly reduced, whereas Cav-3 remained active. Late chronic phase signalling through both proteins was impaired inducing a prediabetic state. Summarizing, caveolins seem to mediate a time-dependent regulation of insulin cascade in response to high-fat diet in muscle.

Fish-oil supplementation induces antiinflammatory gene expression profiles in human blood mononuclear cells

BACKGROUND

Polyunsaturated fatty acids can have beneficial effects on human immune cells, such as peripheral blood mononuclear cells (PBMCs). However, the mechanisms of action of polyunsaturated fatty acids on immune cells are still largely unknown.

OBJECTIVE

The objective was to examine the effects of supplementation with the polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on whole-genome PBMC gene expression profiles, in healthy Dutch elderly subjects participating in a double-blind trial, by using whole-genome transcriptomics analysis.

DESIGN

The subjects were randomly allocated to 1 of 3 groups: 1) consumption of 1.8 g EPA+DHA/d (n = 36), 2) consumption of 0.4 g EPA+DHA/d (n = 37), or 3) consumption of 4.0 g high-oleic acid sunflower oil (HOSF)/d (n = 38). All supplements were given in capsules. Before and after 26 wk of intervention, blood samples were collected. Microarray analysis was performed on PBMC RNA from 23 subjects who received 1.8 g EPA+DHA/d and 25 subjects who received HOSF capsules. Quantitative real-time polymerase chain reaction was performed in all 111 subjects.

RESULTS

A high EPA+DHA intake changed the expression of 1040 genes, whereas HOSF intake changed the expression of only 298 genes. EPA+DHA intake resulted in a decreased expression of genes involved in inflammatory- and atherogenic-related pathways, such as nuclear transcription factor kappaB signaling, eicosanoid synthesis, scavenger receptor activity, adipogenesis, and hypoxia signaling.

CONCLUSION

These results are the first to show that intake of EPA+DHA for 26 wk can alter the gene expression profiles of PBMCs to a more antiinflammatory and antiatherogenic status. This trial was registered at clinicaltrials.gov as NCT00124852.

Candidate gene microarray analysis in peripheral blood cells for studying hypertension/obesity

AIMS

The gene expression of 182 cardiovascular candidate genes was measured in high quality groups of individuals (n = 20) by microarrays to determine whether a subset of genes would discriminate obese and hypertensive individuals, in spite of the existence of a close link between these two cardiovascular risk factors.

MATERIALS & METHODS

The results were validated on the 20 subjects used for microarray analysis and on 62 additional individuals by real-time PCR.

RESULTS

The first analysis, where patient groups were compared with healthy subjects, revealed 15 out of 182 genes that differed in hypertensive, obese or obesity-related hypertensive individuals. These genes were ALOX5, APOA2, SELL, RGS2, CD14, FPR1, CAMP, DEFA3, DEFA4, CBS, CHRM1, ICAM1, NR1H2, SCNN1B and TGFB1. A second analysis was carried out in which patient groups were compared with each other, demonstrating FPR1 and DEFA3 as being significant genes discriminating patient groups. Furthermore, an analysis stratified by sex revealed that, with the exception of DEFA3, there are no other common genes between men and women.

DISCUSSION

We were able to indentify a number of interesting genes that distinguish patient and healthy subject groups as well as patient groups between them.

CONCLUSION

In addition, it seems that gender plays an important role, at least for some of the genes we tested. These findings may have important implications in the screening and etiology of hypertension or obesity, and could further help to focus on these specific mRNAs as antisense therapy targets.