European Journal of Nutrition (v.48, #8)

The effect of fatty or lean fish intake on inflammatory gene expression in peripheral blood mononuclear cells of patients with coronary heart disease by Vanessa D. F. de Mello; Arja T. Erkkilä; Ursula S. Schwab; Leena Pulkkinen; Marjukka Kolehmainen; Mustafa Atalay; Hanna Mussalo; Maria Lankinen; Matej Orešič; Seppo Lehto; Matti Uusitupa (447-455).
Little is known about the effect of fish consumption on gene expression of inflammation-related genes in immune cells in coronary heart disease (CHD).We sought to evaluate the effect of a fatty fish (FF) or a lean fish (LF) diet on the modulation of inflammatory and endothelial function-related genes in peripheral blood mononuclear cells (PBMCs) of subjects with CHD, and its association with serum fatty acid (FA) profile and lipid metabolic compounds.Data from 27 patients randomized into an 8-week FF (n = 10; mean ± SD: 4.3 ± 0.4 portions of fish per week), LF (n = 11; 4.7 ± 1.1 portions of fish per week), or control diet (n = 6; 0.6 ± 0.4 portions of fish per week) were analyzed. The mRNA expression was measured using real-time PCR.The effect of the intervention on the mRNA expression of the genes studied did not differ among groups. In the FF group, however, the decrease in arachidonic acid to eicosapentaenoic acid (AA:EPA) ratio in cholesterol ester and phospholipid fractions strongly correlated with the change in IL1B mRNA levels (r s = 0.60, P = 0.06 and r s = 0.86, P = 0.002, respectively). In the LF group, the decrease in palmitic acid and total saturated FAs in cholesterol esters correlated with the change in intercellular cell adhesion molecule-1 (ICAM1) expression (r s = 0.64, P = 0.04 for both). Circulating levels of soluble ICAM-1 decreased only in the LF group (P < 0.05).The intake of FF or LF diet did not alter the expression of inflammatory and endothelial function-related genes in PBMCs of patients with CHD. However, the decrease in AA:EPA ratio in serum lipids in the FF group may induce an anti-inflammatory response at mRNA levels in PBMCs. A LF diet might benefit endothelial function, possibly mediated by the changes in serum FA composition.
Keywords: Fish; Fatty acids; Gene expression; Inflammation; Endothelial function; ICAM; IL-1β

Effects of galacto-oligosaccharide ingestion on the mucosa-associated mucins and sucrase activity in the small intestine of mice by Géraldine Leforestier; Anne Blais; François Blachier; Agnès Marsset-Baglieri; Anne-Marie Davila-Gay; Emmanuel Perrin; Daniel Tomé (457-464).
Galacto-oligosaccharides (GOS) are non-digestible oligosaccharides with short galactosyl chain units produced by lactose fermentation which are considered as prebiotics. Only few studies have investigated the effects of GOS medium-term ingestion on the small intestinal epithelium characteristics.In this study, we evaluated the consequences of GOS ingestion on small intestinal mucosal morphology, on brush-border membrane enzyme activities and on mucin content in BALB/c mice. Mice received the experimental diets for 4 weeks and then the small intestine was collected to measure sucrase, lactase and alkaline phosphatase activities, to study the villus heights in the jejunum mucosa and to determine mucosal mucin content as well as MUC-2 and MUC-4 mRNAs expression by qRT-PCR.Our results showed that GOS has no detectable effect on the intestine villus height but increased the total protein content by twofold. Sucrase activity was significantly increased in the intestinal mucosa recovered from animals fed the GOS diet without any detectable modification of lactase and phosphatase activities. Interestingly, GOS was also able to increase sucrase activity in cultured Caco-2 cells raising the view that they likely act directly on these cells. Furthermore, GOS was found to markedly increase O-linked glycoproteins associated with the intestinal mucosa without modifying MUC-2, MUC-4 mRNAs expression. Lastly, TNF-α mRNA expression was also not modified after GOS ingestion.These results suggest that, in BALB/c mice, 4-week GOS ingestion is able to increase the small intestinal mucosa-associated mucin content and enterocyte-associated sucrase activity without modifying villus height.
Keywords: Galacto-oligosaccharides; Intestinal mucosa; MUC genes; Mucins

Hepatic lipid metabolism response to dietary fatty acids is differently modulated by PPARα in male and female mice by Anne Morise; Charles Thomas; Jean-François Landrier; Philippe Besnard; Dominique Hermier (465-473).
In human beings, women are at lower risk of cardiovascular diseases, and respond differently from men to dietary fatty acids.The aim of the present study was to investigate (i) the influence of gender on the response of lipid metabolism to dietary n-3 PUFA, and (ii) the contribution of PPARα to this response.Male and female mice, wild-type (WT) and PPARα-null (KO), were fed on diets rich in either saturated FA (SFA) or 18:3 n-3 (ALA). Lipid composition, mRNA levels and certain activities of key enzymes and major transcription factors were determined in the liver. WT mice were slightly affected by dietary FA. However, in WT female mice, but not in males, mRNA levels of PPARα-dependent genes (L-FABP, ACO) were higher in the mice fed on the ALA-rich diet. When compared to WT mice, KO female mice exhibited a decreased lipogenesis capacity (40% lower FAS, ACC, and SREBP-1c mRNA level), whereas KO males showed a decrease in peroxisomal β-oxidation (activity and expression of ACO reduced by 20 and 40%, respectively). When compared to SFA-fed KO mice, steatosis was twice lower in KO mice fed on ALA, despite the absence of dietary effect on plasma TG, CPT1 and ACO activities, or ACC and FAS expression. Besides, in mice on the SFA diet, steatosis was alleviated in females, and CPT1 expression was up-regulated to a higher extent in females than in males (2.7- and 3.6-fold, respectively, as compared to the corresponding WT groups).Our data suggests estrogen to modulate the regulation of hepatic lipid metabolic pathway by dietary fatty acids. Besides, PPARα invalidation resulted in unexpected regulations by ALA of its known targets and was compensated partly in females, which was therefore less sensitive to the detrimental effects of a SFA-rich diet.
Keywords: Lipid metabolism; α-Linolenic acid; Gender; n-3 PUFA; PPARα; Mouse

Advanced glycation end products strongly activate platelets by Thomas Gawlowski; Bernd Stratmann; Ruth Ruetter; Christina E. Buenting; Barbara Menart; Jürgen Weiss; Helen Vlassara; Theodor Koschinsky; Diethelm Tschoepe (475-481).
Diabetes mellitus is characterized by hyperglycemia that plays an important role in the pathogenesis of diabetic complications including cardiovascular diseases. Moreover, hyperglycemia induces increased generation of advanced glycation end products (AGEs). The activation of platelets is associated with the development of cardiovascular diseases.The question whether AGEs acutely induce platelet activation as a response to exogenous stimulus is addressed.The effect of AGEs derived from food and human serum being purified by lysozyme affinity chromatography was examined by incubating in vitro freshly isolated blood platelets from fasted subjects at various concentrations and different time points. Platelet activation, determined as expression of surface markers CD62 and CD63, and the presence of the receptor for AGEs (RAGE) in platelet membranes was measured by flow cytometric analysis using specific antibodies.Incubation with food-derived as well as serum-derived AGEs stimulated significantly the expression of CD62 up to 7.1-fold and CD63 up to 2.2-fold at the platelet surface membrane as a function of concentration and time. Incubation with thrombin or AGEs significantly increased RAGE expression twofold at the platelet surface membrane.The increase in surface activation marker and RAGE expression in platelets, resulting from concentrations of AGEs that occur in vivo after a meal or a drink as a source of exogenous AGEs, points to signaling mechanisms for food AGEs that could favor the precipitation of acute postprandial ischemic events.
Keywords: Advanced glycation end products; Atherothrombosis; Diabetes mellitus; Flow cytometry; Platelet activation; RAGE

Modulation of detoxification enzymes by watercress: in vitro and in vivo investigations in human peripheral blood cells by Thomas Hofmann; A. Kuhnert; A. Schubert; C. Gill; I. R. Rowland; B. L. Pool-Zobel; M. Glei (483-491).
Epidemiological studies indicate that consumption of cruciferous vegetables (CV) can reduce the risk of cancer. Supposed mechanisms are partly the inhibition of phase I and the induction of phase II enzymes.The aim of this study was to investigate in vitro and in vivo effects of watercress (WC), a member of the CV family, on chemopreventive parameters using human peripheral blood mononuclear cells (PBMC) as surrogate cells. We investigated the hypothesis that WC reduces cancer risk by inducing detoxification enzymes in a genotype-dependent manner.In vitro gene expression and enzyme activity experiments used PBMC incubated with a crude extract from fresh watercress (WCE, 0.1–10 μL/mL with 8.2 g WC per 1 mL extract) or with one main key compound phenethyl isothiocyanate (PEITC, 1–10 μM). From an in vivo perspective, gene expression and glutathione S-transferase (GST) polymorphisms were determined in PBMC obtained from a human intervention study in which subjects consumed 85 g WC per day for 8 weeks. The influence of WC consumption on gene expression was determined for detoxification enzymes such as superoxide dismutase 2 (SOD2) and glutathione peroxidase 1 (GPX1), whilst the SOD and GPX activities in red blood cells were also analysed with respect to GST genotypes.In vitro exposure of PBMC to WCE or PEITC (24 h) increased gene expression for both detoxification enzymes GPX1 (5.5-fold, 1 μL/mL WCE, 3.7-fold 1 μM PEITC) and SOD2 (12.1-fold, 10 μL/mL WCE, 7.3-fold, 10 μM PEITC), and increased SOD2 activity (1.9-fold, 10 μL/mL WCE). The WC intervention had no significant effect on in vivo PBMC gene expression, as high individual variations were observed. However, a small but significant increase in GPX (p = 0.025) and SOD enzyme activity (p = 0.054) in red blood cells was observed in GSTM1*0, but not in GSTM1*1 individuals, whilst the GSTT1 genotype had no impact.The results indicate that WC is able to modulate the enzymes SOD and GPX in blood cells in vitro and in vivo, and suggest that the capacity of moderate intake of CV to induce detoxification is dependent in part on the GSTM1 genotype.
Keywords: Chemoprevention; Gene expression; Enzyme activity; Detoxification enzymes; Watercress

ADIPOQ gene polymorphism rs1501299 interacts with fibre intake to affect adiponectin concentration in children: the GENe–Diet Attica Investigation on childhood obesity by Ioanna Ntalla; George Dedoussis; Mary Yannakoulia; Melissa C. Smart; Eirini Louizou; Sophia D. Sakka; Constantina Papoutsakis; Philippa J. Talmud (493-497).
Adiponectin, an adipose-derived hormone with central and peripheral actions, is involved in the regulation of energy homeostasis. Interactions between genetic and environmental factors have been associated with decrease in circulating adiponectin leading to obesity.We investigated whether variants of the ADIPOQ gene encoding adiponectin interact with diet to predict serum adiponectin concentration.A cross-sectional study of healthy school-aged children of Greek origin (n = 991), aged 11.2 ± 0.6 years was conducted in 2005–2006. DNA was genotyped for two SNPs [rs1501299 (n = 741) and rs17300539 (n = 713)] located in the ADIPOQ gene. Detailed dietary, behavioural, lifestyle, anthropometric and biochemical data were recorded for all participants.Both SNPs were in HWE. The rs1501299 (GG vs GT + TT) × fibre interaction was significantly associated with adiponectin concentration (P = 0.028). When fibre intake was low, GG homozygotes exhibited significantly higher adiponectin concentrations compared to T allele carriers (mean ± SD = 5.1 ± 2.7 vs 4.2 ± 2.3; P = 0.020).In the present study, the rs1501299 × fibre interaction was significantly associated with adiponectin levels; in specific, GG homozygotes exhibited higher adiponectin levels compared to T carriers under conditions of lower fibre intake.
Keywords: ADIPOQ gene SNP; Adiponectin; Children; Fibre; Gene–diet interactions

Food derived carbonyl compounds affect basal and stimulated secretion of interleukin-6 and -8 in Caco-2 cells by Sabine Kuntz; Silvia Rudloff; Julia Ehl; Reinhard G. Bretzel; Clemens Kunz (499-503).
The carbonyl compounds methylglyoxal (MG) and glyoxal (G) are reactive intermediates generated in a variety of foods and beverages during processing and prolonged storage.We investigated direct effects of these compounds on intestinal cells determining the basal and stimulated secretion of IL-8 and IL-6 in vitro.MG or G induced a concentration dependent enhancement of IL-8 and IL-6 secretion compared to baseline levels. A co-incubation with pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) or lipopolysaccharides (LPS) and increasing MG concentrations further enhanced IL-8 and IL-6 secretion. For G, however, this additive effect was only observed in TNF-α and IL-1β treated cells, but not after co-incubation with LPS.These results suggest a pro-inflammatory effect of G and MG at high concentrations in human intestinal cells by stimulating IL-8 and IL-6 cytokine levels. Effects of G and MG in combination with other cytokines may negatively affect inflammatory processes.
Keywords: Caco-2 cells; Glyoxal; Methylglyoxal; Interleukin-8; Interleukin-6