Temporal changes in postprandial blood transcriptomes reveal subject-specific pattern of expression of innate immunity genes after a high-fat meal.

White blood cells are among the first responders to dietary components and their metabolites absorbed from the gut. The objective of this study was to determine the whole blood transcriptome response to high-fat challenge meals. A total of 45 fasting and postprandial (3-h and 6-h) whole blood transcriptomes from 5 subjects in a crossover intervention trial of a high-fat meal supplemented with placebo, blueberry powder or docosahexaenoic acid (DHA) were analyzed using RNA sequencing. Select target genes were validated by quantitative reverse-transcription polymerase chain reaction in 180 samples from 20 subjects. The largest contributor to variance was the subject (13,856 genes differentially expressed), followed by the subject on a specific day (2276 genes), followed by the subject's postprandial response (651 genes). After determining the nonsignificance of individual dietary treatments (blueberry, DHA, placebo), treatments were used as replicates to examine postprandial responses to a high-fat meal. The universal postprandial response (95 genes) was associated with lipid utilization, fatty acid beta-oxidation and circadian rhythms. Subject-specific postprandial responses were enriched for genes involved in the innate immune response, particularly those of pattern recognition receptors and their downstream signaling components. Genes involved in innate immune responses are differentially expressed in a subject-specific and time-dependent manner in response to the high-fat meals. These genes can serve as biomarkers to assess individual responsiveness to a high-fat diet in inducing postprandial inflammation. Furthermore, the dynamic temporal change in gene expression in postprandial blood suggests that monitoring these genes at multiple time points is necessary to reveal responders to dietary intervention.

Green tea extract and catechol-O-methyltransferase genotype modify the post-prandial serum insulin response in a randomised trial of overweight and obese post-menopausal women.

BACKGROUND: Green tea extract (GTE) may be involved in a favourable post-prandial response to high-carbohydrate meals. The catechol-O-methyltransferase (COMT) genotype may modify these effects. We examined the acute effects of GTE supplementation on the post-prandial response to a high-carbohydrate meal by assessing appetite-associated hormones and glucose homeostasis marker concentrations in women who consumed 843 mg of (-)-epigallocatechin-3-gallate (EGCG) or placebo capsules for 11-12 months. METHODS: Sixty Caucasian post-menopausal women (body mass index ≥ 25.0 kg m-2 ) were included in a randomised, double-blind feeding study. GTE was consumed with a breakfast meal [2784.0 kJ (665.4 kcal); 67.2% carbohydrate]. Blood samples were drawn pre-meal, post-meal, and every 30 min for 4 h. Participants completed six satiety questionnaires. RESULTS: Plasma leptin, ghrelin and adiponectin did not differ between GTE and placebo at any time point; COMT genotype did not modify these results. Participants randomised to GTE with the high-activity form of COMT (GTE-high COMT) had higher insulin concentrations at time 0, 0.5 and 1.0 h post-meal compared to all COMT groups randomised to placebo. Insulin remained higher in the GTE-high COMT group at 1.5, 2.0 and 2.5 h compared to Placebo-low COMT (P < 0.02). GTE-high COMT had higher insulin concentrations at times 0, 0.5, 1.0, 1.5 and 2.0 h compared to the GTE-low COMT (P ≤ 0.04). Area under the curve measurements of satiety did not differ between GTE and placebo. CONCLUSIONS: GTE supplementation and COMT genotype did not alter acute post-prandial responses of leptin, ghrelin, adiponectin or satiety, although it may be involved in post-meal insulinaemic response of overweight and obese post-menopausal women.

Evidence that ghrelin may be associated with the food intake of gibel carp (Carassius auratus gibelio).

Ghrelin, a non-amidated peptide hormone, is a potent anorectic neuropeptide implicated in feeding regulation in mammals and non-mammalian vertebrates. However, the involvement of ghrelin in the feeding behavior of teleosts has not been well understood. To better understand the role of ghrelin in the regulation of appetite in fish, in this study, we cloned the cDNAs encoding ghrelin and investigated their mRNA distributions in gibel carp tissues. We also assessed the effects of different nutritional status on ghrelin mRNA abundance. Ghrelin mRNAs were ubiquitously expressed in ten tissues (intestine, liver, brain, mesonephron, head kidney, spleen, skin, heart, muscle, gill and pituitary gland), and relatively high expression levels were detected in the gut. Postprandial studies analysis revealed a significant postprandial decrease in ghrelin mRNA expression in the gut (1 and 3 h after the regular feeding time). In addition, ghrelin mRNA expression in the gut significantly increased at day 7 after fasting and declined sharply after refeeding, which suggested that ghrelin might be involved in the regulation of appetite in gibel carp. Overall, our result provides basis for further investigation into the regulation of feeding in gibel carp.

Postprandial kinetics of gene expression of proteins involved in the digestive process in rainbow trout (O. mykiss) and impact of diet composition.

The impact of increased incorporation of plant ingredients on diets for rainbow trout was evaluated in terms of gene expression of gastric (gastric lipase, pepsinogen) and intestinal (prolidase, maltase, phospholipase A2) digestive enzymes and nutrient transporters (peptide and glucose transporters), as well as of postprandial levels of plasma glucose, triglycerides and total free amino acids. For that purpose, trout alevins were fed from the start of exogenous feeding one of three different experimental diets: a diet rich in fish meal and fish oil (FM-FO), a plant-based diet (noFM-noFO) totally free from fish meal and fish oil, but containing plant ingredients and a Mixed diet (Mixed) intermediate between the FM-FO and noFM-noFO diets. After 16 months of rearing, all fish were left unfed for 72 h and then given a single meal to satiation. Blood, stomach and anterior intestine were sampled before the meal and at 2, 6 and 12 h after this meal. The postprandial kinetics of gene expression of gastric and intestinal digestive enzymes and nutrient transporters were then followed in trout fed the FM-FO diet. The postprandial profiles showed that the expression of almost all genes studied was stimulated by the presence of nutrients in the digestive tract of trout, but the timing (appearance of peaks) varied between genes. Based on these data, we have focused on the molecular response to dietary factors in the stomach and the intestine at 6 and 12 h after feeding, respectively. The reduction in FM and FO levels of dietary incorporation induced a significant decrease in the gene expression of gastric lipase, GLUT2 and PEPT1. The plasma glucose and triglycerides levels were also reduced in trout fed the noFM-noFO diet. Consequently, the present study suggests a decrease in digestive capacities in trout fed a diet rich in plant ingredients.

Molecular characterization of carnitine palmitoyltransferase IA in Megalobrama amblycephala and effects on its expression of feeding status and dietary lipid and berberine.

Carnitine palmitoyltransferase I (CPT I, EC 2.3.1.21) controls the main regulatory step of fatty acid oxidation, and hence studies of its molecular characterization are useful to understand lipid metabolism in cultured fish. Here, a full-length cDNA coding CPT I was cloned from liver of blunt snout bream Megalobrama amblycephala. This cDNA obtained covered 2499bp with an open reading frame of 2181bp encoding 726 amino acids. This CPT I mRNA predominantly expressed in heart and white muscle, while little in eye and spleen. The phylogenetic tree constructed on the basis of sequence alignments among several vertebrate species suggests that this blunt snout bream CPT I sequence belongs to the CPT IA family. In order to investigate the characterization of CPT IA mRNA expression, post-prandial experiment and feeding trial were conducted. The results showed that CPT IA mRNA expression was unchanged from 2 to 12h, and then significantly increased at 24h post-feeding in liver and heart. Berberine, an alkaloid, was identified as a promising lipid-lowering drug. In order to elucidate the effect of berberine on CPT I expression, fish were fed for 8 weeks with three diets (low-fat diet (LFD, 5% fat), high-fat diet (HFD, 15% fat), and berberine-supplemented diet (BSD, 15% fat). The results showed that HFD could decrease the expression of CPT IA and PPARα, while BSD increased those expressions.

Postprandial activation of p53-dependent DNA repair is modified by Mediterranean diet supplemented with coenzyme Q10 in elderly subjects.

BACKGROUND: Alterations in the expression levels of genes and proteins involved in oxidative stress and DNA damage response underlie the phenotypic changes associated with aging. We have investigated whether the quality of dietary fat alters postprandial gene expression and protein levels involved in p53-dependent DNA repair and whether the supplementation with Coenzyme Q10 improves this situation in an elderly population. METHODS: Twenty participants were randomized to receive three isocaloric diets each for 4 weeks: Mediterranean diet supplemented with Coenzyme Q10, Mediterranean diet, saturated fatty acid-rich diet. After a 12-hour fast, volunteers consumed a breakfast with a fat composition similar to that consumed in each of the diets. Gadd45a, Gadd45b, OGG1, APE-1/Ref-1, DNApolß, and XPC gene expression and nuclear Gadd45a, APE-1/Ref-1, and DNApolß protein levels were determined in peripheral blood mononuclear cells. RESULTS: Mediterranean diet and Mediterranean diet supplemented with Coenzyme Q10diets downregulated Gadd45a protein levels compared with the saturated fatty acid-rich diet. Moreover, Mediterranean diet supplemented with Coenzyme Q10diet evoked lower postprandial Gadd45a, Gadd45b, XPC, DNApolß and OGG1 gene expression and lower APE-1/Ref-1 and DNApolß protein levels than the saturated fatty acid-rich diet. CONCLUSIONS: Our results support a beneficial effect of Mediterranean diet and Mediterranean diet supplemented with Coenzyme Q10 on DNA damage as compared to the detrimental action of a saturated fatty acid-rich diet, which triggers the p53-dependent DNA repair machinery.

Mediterranean diet supplemented with coenzyme Q10 induces postprandial changes in p53 in response to oxidative DNA damage in elderly subjects.

Coenzyme Q10 (CoQ) is a powerful antioxidant that reduces oxidative stress. We explored whether the quality of dietary fat alters postprandial oxidative DNA damage and whether supplementation with CoQ improves antioxidant capacity by modifying the activation/stabilization of p53 in elderly subjects. In this crossover study, 20 subjects were randomly assigned to receive three isocaloric diets during 4 weeks each: (1) Mediterranean diet (Med diet), (2) Mediterranean diet supplemented with CoQ (Med+CoQ diet), and (3) saturated fatty acid-rich diet (SFA diet). Levels of mRNAs were determined for p53, p21, p53R2, and mdm2. Protein levels of p53, phosphorylated p53 (Ser20), and monoubiquitinated p53 were also measured, both in cytoplasm and nucleus. The extent of DNA damage was measured as plasma 8-OHdG. SFA diet displayed higher postprandial 8-OHdG concentrations, p53 mRNA and monoubiquitinated p53, and lower postprandial Mdm2 mRNA levels compared with Med and Med+CoQ diets (p < 0.05). Moreover, Med+CoQ diet induced a postprandial decrease of cytoplasmatic p53, nuclear p-p53 (Ser20), and nuclear and cytoplasmatic monoubiquitinated p53 protein (p < 0.05). In conclusion, Med+CoQ diet improves oxidative DNA damage in elderly subjects and reduces processes of cellular oxidation. Our results suggest a starting point for the prevention of oxidative processes associated with aging.

Effect of the fat composition of a single high-fat meal on inflammatory markers in healthy young women.

The aim of the present study was to examine the effect of a single high-fat meal with different fat quality on circulating inflammatory markers and gene expression in peripheral blood mononuclear cells (PBMC) to elucidate the role of fat quality on postprandial inflammation. A postprandial study with fourteen healthy females consuming three test meals with different fat quality was performed. Test days were separated by 2 weeks. Fasting and postprandial blood samples at 3 and 6 h after intake were analysed. The test meal consisted of three cakes enriched with coconut fat (43 % energy as saturated fat and 1 % energy as α-linolenic acid (ALA)), linseed oil (14 % energy as ALA and 30 % energy as saturated fat) and cod liver oil (5 % energy as EPA and DHA and 5 % energy as ALA in addition to 31 % energy as saturated fat). In addition, ex vivo PBMC experiments were performed in eight healthy subjects investigating the effects of EPA and ALA on release and gene expression of inflammatory markers. The IL-8 mRNA level was significantly increased after intake of the cod liver oil cake at 6 h compared with fasting level, which was significantly different from the effect observed after the intake of linseed cake. In contrast, no effect was seen on circulating level of IL-8. In addition, ALA and EPA were shown to elicit different effects on the release and mRNA expression levels of inflammatory markers in PBMC cultured ex vivo, with EPA having the most prominent pro-inflammatory potential.

Characterization of human gene expression changes after olive oil ingestion: an exploratory approach.

Olive oil consumption is protective against risk factors for cardiovascular and cancer diseases. A nutrigenomic approach was performed to assess whether changes in gene expression could occur in human peripheral blood mononuclear cells after oli ve oil ingestion at postprandial state. Six healthy male volunteers ingested, at fasting state, 50 ml of olive oil. Prior to intervention a 1-week washout period with a controlled diet and sunflower oil as the only source of fat was followed. During the 3 days before and on the intervention day, a very low-phenolic compound diet was followed. At baseline (0 h) and at post-ingestion (6 h), total RNA was isolated and gene expression (29,082 genes) was evaluated by microarray. From microarray data, nutrient-gene interactions were observed in genes related to metabolism, cellular processes, cancer, and atherosclerosis (e.g. USP48 by 2.16; OGT by 1.68-fold change) and associated processes such as inflammation (e.g. AKAP13 by 2.30; IL-10 by 1.66-fold change) and DNA damage (e.g. DCLRE1C by 1.47; POLK by 1.44- fold change). When results obtained by microarray were verified by qRT-PCR in nine genes, full concordance was achieved only in the case of up-regulated genes. Changes were observed at a real-life dose of olive oil, as it is daily consumed in some Mediterranean areas. Our results support the hypothesis that postprandial protective changes related to olive oil consumption could be mediated through gene expression changes.

Polyunsaturated fatty acids modulate the effect of TCF7L2 gene variants on postprandial lipemia.

The transcription factor 7-like 2 (TCF7L2) has been recently associated with diabetes risk, and it may exert its effect through metabolic syndrome (MetS)-related traits and be subjected to modification by environmental factors. We investigated the effect of single nucleotide polymorphisms (SNP), rs7903146 and rs12255372, within the TCF7L2 locus on postprandial lipemia and other MetS-related traits and their modulation by dietary fat. Data were collected from 1083 European Americans participating in the Genetics of Lipid Lowering Drugs and Diet Network Study. Carriers of the minor T allele at the C/T rs7903146 SNP had higher fasting plasma glucose (P = 0.012), lower homeostasis model assessment of beta cell function (P = 0.041), higher plasma VLDL (P = 0.035), and lower large LDL particle (P = 0.007) concentrations and higher risk of MetS (P = 0.011) than CC individuals. Moreover, we identified significant interactions between this SNP and PUFA intake modulating fasting VLDL particle concentrations (P = 0.016) and postprandial triglycerides (TG) (P = 0.028), chylomicrons (P = 0.025), total VLDL (P = 0.026), and large VLDL (P = 0.018) concentrations. Thus, only T allele carriers with a PUFA intake > or = 7.36% of energy had elevated fasting plasma VLDL concentrations and postprandial TG-rich lipoproteins. These variables did not differ in T allele carriers and noncarriers in the low-PUFA intake group. Moreover, these significant interactions were due exclusively to (n-6) PUFA intake. In summary, high (n-6) PUFA intakes (> or = 6.62% of energy intake) were associated with atherogenic dyslipidemia in carriers of the minor T allele at the TCF7L2 rs7903146 SNP and may predispose them to MetS, diabetes, and cardiovascular disease.