Activation of nuclear factor-kappa B subunits c-Rel, p65 and p50 by plasma lipids and fatty acids across the menstrual cycle.

This study focused on a comprehensive analysis of the canonical activation pathway of the redox-sensitive transcription factor nuclear factor-kappa B (NF-κB) in peripheral blood mononuclear cells, addressing c-Rel, p65 and p50 activation in 28 women at early (T1) and late follicular (T2) and mid (T3) and late luteal (T4) phase of the menstrual cycle, and possible relations with fasting plasma lipids and fatty acids. For the first time, strong inverse relations of c-Rel with apolipoprotein B were observed across the cycle, while those with LDL cholesterol, triglycerides as well as saturated (SFA), particularly C14-C22 SFA, monounsaturated (MUFA), and polyunsaturated fatty acids (PUFA) clustered at T2. In contrast, p65 was positively related to LDL cholesterol and total n-6 PUFA, while p50 did not show any relations. C-Rel was not directly associated with estradiol and progesterone, but data suggested an indirect C22:5n-3-mediated effect of progesterone. Strong positive relations between estradiol and individual SFA, MUFA and n-3 PUFA at T1 were confined to C18 fatty acids; C18:3n-3 was differentially associated with estradiol (positively) and progesterone (inversely). Given specific roles of c-Rel activation in immune tolerance, inhibition of c-Rel activation by higher plasma apolipoprotein B and individual fatty acid concentrations could have clinical implications for female fertility.

Progesterone-associated arginine decline at luteal phase of menstrual cycle and associations with related amino acids and nuclear factor kB activation.

BACKGROUND/OBJECTIVES: Given their role in female reproduction, the effects of progesterone on arginine and related amino acids, polyamines and NF-κB p65 activation were studied across the menstrual cycle. METHODS: Arginine, ornithine and citrulline as well as putrescine, spermidine, spermine, and N-acetyl-putrescine were determined in plasma, NF-κB p65 activation in peripheral blood mononuclear cells and progesterone in serum of 28 women at early (T1) and late follicular (T2) and mid (T3) and late (T4) luteal phase. RESULTS: Arginine and related amino acids declined from T1 and T2 to T3 and T4, while progesterone increased. At T3, arginine, ornithine, and citrulline were inversely related with progesterone. Changes (ΔT3-T2) in arginine, ornithine, and citrulline were inversely related with changes (ΔT3-T2) in progesterone. Ornithine and citrulline were positively related with arginine, as were changes (ΔT3-T2) in ornithine and citrulline with changes (ΔT3-T2) in arginine. At T2, NF-κB p65 activation was positively related with arginine. Polyamines did not change and were not related to progesterone. All results described were significant at P < 0.001. CONCLUSIONS: This study for the first time provides data, at the plasma and PBMC level, supporting a proposed regulatory node of arginine and related amino acids, progesterone and NF-κB p65 at luteal phase of the menstrual cycle, aimed at successful preparation of pregnancy.

Circulating leptin and NF-κB activation in peripheral blood mononuclear cells across the menstrual cycle.

Using the menstrual cycle as a model, this study focused on longitudinal changes and associations within a physiological network known to play a role in female fertility, including, as biologically active nodes, NF-κB, leptin and adiponectin, ß-carotene, adipose tissue, and progesterone. In 28 women, leptin, adiponectin, ß-carotene, and progesterone concentrations, NF-κB p65 and p50 activation in peripheral blood mononuclear cells (known to possess estrogen, progesterone and leptin receptors), total body fat (TBF) and subcutaneous adipose tissue (SAT) mass were determined at early (T1) and late follicular (T2) and mid (T3) and late (T4) luteal phase. Leptin and adiponectin concentrations were higher, while NF-κB p65 activation was lower at T3 compared with T1. NF-κB p65 activation was inversely related to leptin concentrations at T1, T3, and T4. ß-Carotene was inversely related to leptin (T1,T2,T4) and SAT (T1,T3,T4). NF-κB p50 activation was inversely related to TBF (T4) and SAT (T3,T4), and leptin was positively related to TBF and SAT (T1-T4). Progesterone was inversely related to leptin (T2,T3), adiponectin (T3), TBF (T3,T4), and SAT (T2,T3,T4). By providing evidence of luteal phase-specific reduced NF-κB p65 activation in women under physiological conditions, this study bridges the gap between existing evidence of a Th1-Th2 immune response shift induced by reduced NF-κB p65 activation and a Th1-Th2 shift previously observed at luteal phase. For the first time, inverse regressions suggest inhibitory effects of leptin on NF-κB p65 activation at luteal phase, along with inhibitory effects of leptin as well as adiponectin on progesterone production in corpus luteum. © 2016 The Authors BioFactors published by Wiley Periodicals, Inc. on behalf of International Union of Biochemistry and Molecular Biology. 24(4):376-387, 2016.

Imidazopurinones are markers of physiological genomic damage linked to DNA instability and glyoxalase 1-associated tumour multidrug resistance.

Glyoxal and methylglyoxal are reactive dicarbonyl metabolites formed and metabolized in physiological systems. Increased exposure to these dicarbonyls is linked to mutagenesis and cytotoxicity and enhanced dicarbonyl metabolism by overexpression of glyoxalase 1 is linked to tumour multidrug resistance in cancer chemotherapy. We report herein that glycation of DNA by glyoxal and methylglyoxal produces a quantitatively important class of nucleotide adduct in physiological systems-imidazopurinones. The adduct derived from methylglyoxal-3-(2'-deoxyribosyl)-6,7-dihydro-6,7-dihydroxy-6/7-methylimidazo-[2,3-b]purine-9(8)one isomers-was the major quantitative adduct detected in mononuclear leukocytes in vivo and tumour cell lines in vitro. It was linked to frequency of DNA strand breaks and increased markedly during apoptosis induced by a cell permeable glyoxalase 1 inhibitor. Unexpectedly, the DNA content of methylglyoxal-derived imidazopurinone and oxidative marker 7,8-dihydro-8-oxo-2'-deoxyguanosine were increased moderately in glyoxalase 1-linked multidrug resistant tumour cell lines. Together these findings suggest that imidazopurinones are a major type of endogenous DNA damage and glyoxalase 1 overexpression in tumour cells strives to counter increased imidazopurinone formation in tumour cells likely linked to their high glycolytic activity.

Antioxidant status of patients on peritoneal dialysis: associations with inflammation and glycoxidative stress.

BACKGROUND: Patients on peritoneal dialysis (PD) frequently exhibit oxidant-antioxidant imbalance, advanced glycation end-product overload, and subclinical inflammation but the interrelations between these pathophysiological changes have not been fully elucidated. SUBJECTS AND METHODS: To study possible associations, a cross-sectional study of antioxidant status, glycoxidative stress, and inflammation, using HPLC and ELISA methods, was undertaken in 37 PD patients and age- and sex-matched healthy controls. RESULTS: Plasma ascorbate concentrations were low in patients not taking at least low-dose vitamin C supplements. In patients taking vitamin C supplements, there was a positive relation between ascorbate and pentosidine concentrations. Vitamin E and carotenoid concentrations were comparable between patients and controls, while lycopene and lutein/zeaxanthin concentrations were lower. Interleukin-6, C-reactive protein (CRP), and pentosidine concentrations were elevated in PD patients. beta-Cryptoxanthin, lycopene, and lutein/zeaxanthin concentrations were inversely related to interleukin-6 concentrations. beta-Cryptoxanthin concentrations were also inversely related to CRP concentrations. Pentosidine showed a low dialysate-to-plasma ratio, indicating low peritoneal clearance. Pentosidine concentrations increased with duration of PD therapy, while alpha- and beta-carotene concentrations decreased. Malondialdehyde concentrations were elevated compared to controls but remained within the normal range. Retinol concentrations decreased with PD therapy and were inversely related to interleukin-6 and CRP concentrations. CONCLUSIONS: Low-dose vitamin C supplements and a carotenoid-rich diet should be recommended for PD patients to maintain normal antioxidant status and efficiently counteract the chronic inflammatory response, rather than high doses of vitamin C, which could play a role as a precursor of pentosidine.

Circulating adipokines and the protective effects of hyperinsulinemia in inflammatory bowel disease.

OBJECTIVE: Adipokines are fat-derived hormones and cytokines with immune-modulating and metabolic properties. Most of them are associated with insulin resistance. The aim of the present investigation was to evaluate circulating levels of adipokines and glucose homeostasis in patients with inflammatory bowel disease (IBD) and to evaluate possible associations with the course and characteristics of the disease. METHODS: Serum leptin, resistin, visfatin, retinol-binding protein-4, adiponectin, glucose, insulin, and inflammatory parameters were analyzed in 93 patients with inactive IBD (49 with Crohn's disease [CD], 44 with ulcerative colitis [UC]), 35 patients with active IBD (18 with CD, 17 with UC), and 37 age- and body mass index-matched healthy controls. Ninety-two patients were followed for 6 mo. RESULTS: Leptin was similar in patients with IBD and controls, whereas resistin and visfatin were increased in patients with active disease but not in those in remission. In active and inactive disease, adiponectin was decreased (P < 0.001) and retinol-binding protein-4 was increased (P < 0.001) compared with controls. About 60% of patients with IBD showed increased levels of insulin, whereas serum glucose remained normal, resulting in increased homeostasis model assessment values in most patients. Hyperinsulinemia was associated with the decrease in adiponectin (r = -0.572, P < 0.001) and proved to be an independent protective factor for 6-mo maintenance of remission (P = 0.016). CONCLUSION: IBD led to largely similar alterations in circulating adipokines and hyperinsulinemia in patients with CD and those with UC. The unexpected protective effect of hyperinsulinemia on relapse rate denotes the role of the metabolic-inflammatory response as a modulator in IBD.

Altered status of antioxidant vitamins and fatty acids in patients with inactive inflammatory bowel disease.

BACKGROUND & AIMS: Data regarding the nutritional status, antioxidant compounds and plasma fatty acid (FA) composition in inactive IBD are conflicting. We compared plasma levels of antioxidants and FA of patients with inactive IBD with active IBD and controls. METHODS: Plasma levels of vitamin C, vitamin E, carotenoids, saturated, monounsaturated and polyunsaturated FA, inflammatory markers and nutritional status were determined after an overnight fast in 132 patients with quiescent IBD (40.6+/-13.2 years, 87F/45M), 35 patients with active disease (37.9+/-12.1 years, 25F/10M) and 45 age- and BMI-matched healthy controls (38.1+/-10.5 years, 39F/6M). Results are expressed as mean+/-SD or median [25th percentile;75th percentile]. RESULTS: Body mass index (BMI) was normal in inactive (23.9+/-4.7 kg/m(2)), active IBD (22.7+/-4.2 kg/m(2)) and controls (22.3+/-1.9 kg/m(2)). Compared with controls patients with quiescent IBD showed significantly decreased plasma levels of carotenoids (1.85 [1.37;2.56] vs 1.39 [0.88;1.87] micromol/L) and vitamin C (62.3 [48.7;75.0] vs 51.0 [36.4;77.6] micromol/L), increased levels of saturated FA (3879 [3380;4420] vs 3410 [3142;3989] micromol/L) and monounsaturated FA (2578 [2258;3089] vs 2044 [1836;2434] micromol/L) and similar levels of vitamin E and polyunsaturated FA. Results in active disease were similar to inactive disease. CONCLUSION: This study shows that antioxidant status and FA profile in a larger population of IBD patients are disturbed independently from disease activity and despite normal overall nutritional status.

Association of a polymorphism in the promoter of the cellular retinoic acid-binding protein II gene (CRABP2) with increased circulating low-density lipoprotein cholesterol.

BACKGROUND: The cellular retinoic acid-binding protein II (CRABP-II), together with nuclear receptors such as the retinoid X receptor (RXR) and retinoic acid receptor (RAR), is involved in the transcriptional regulation of genes that control lipid metabolism via the retinoid signaling pathway and, as such, may be associated with disorders of lipid metabolism. Interestingly, the gene for CRABP-II is located on chromosome 1q21-23, which is a region that has been linked with disorders such as familial combined hyperlipidemia (FCHL), type 2 diabetes mellitus, and partial lipodystrophy, all of which are characterized by dyslipidemia. METHODS: We investigated the hypothesis that the CRABP2 gene is involved in the regulation of lipid metabolism. Using the promoter -394T>C polymorphism of the CRABP2 gene, we performed association studies in three different cohorts: 299 healthy males, 182 HIV-infected patients and 151 patients with familial hypercholesterolemia (FH). All cholesterol measurements were performed in the absence of any lipid-lowering agents. ANOVA was performed on data adjusted for age, body mass index (BMI), gender, and use of protease inhibitors. RESULTS: The frequency of the C allele was 0.03 in the three groups. Among healthy males, carriers of the C allele had 9% higher total plasma cholesterol (p=0.027) and 13% higher low-density lipoprotein cholesterol (LDL-C) concentrations (p=0.020). In HIV-infected patients, multivariate analysis of four measures over a 1-year period showed that carriers of the C allele had significantly higher LDL-C of between 10% and 31% (p=0.001) compared with non-carriers of the allele. FH patients who were carriers of the C allele had 16% higher LDL-C (p=0.038). The C allele was significantly over-represented among hypercholesterolemic patients (p=0.001). CONCLUSIONS: Our results show that the CRABP2 gene, a member of the retinoid signaling pathway, is associated with increased plasma LDL-C concentrations.

Effects of LDL-immunoapheresis on plasma concentrations of vitamin E and carotenoids in patients with familial hypercholesterolemia.

Recently very potent extracorporeal cholesterol-lowering treatment options have become available for patients with hypercholesterolemia. LDL immunoapheresis treatment selectively removes LDL and lipoprotein(a) from the circulation. Since LDL is the major carrier of lipophilic antioxidants in plasma, the purpose of the present study was to assess the effects of a single LDL apheresis treatment on plasma concentrations of tocopherols (alpha- and gamma-tocopherol) and carotenoids (alpha- and beta-carotene, zeaxanthin, cryptoxanthin, canthaxanthin, lycopene, and retinol). Plasma antioxidant concentrations were determined by HPLC in 7 patients with familial hypercholesterolemia before and after LDL immunoapheresis treatment. Plasma concentrations of both alpha- and gamma-tocopherol and the different carotenoids were significantly reduced by LDL apheresis. However, when standardized for cholesterol to adjust for cholesterol removal, alpha- and gamma-tocopherol, retinol, and the more polar carotenoids lutein and zeaxanthin increased in response to apheresis treatment, while the more unpolar carotenoids such as beta-carotene and lycopene did not change. These data demonstrate that a single LDL immunoapheresis treatment affects tocopherols and individual carotenoids differently. This may be explained by differences in chemical structure and preferential association with different lipoproteins. These results further imply that tocopherols, lutein, zeaxanthin, and retinol, are associated in part with lipoproteins and other carriers such as retinol-binding protein that are not removed during apheresis treatment.

Effects of vitamin E and carotenoid status on oxidative stress in health and disease. Evidence obtained from human intervention studies.

Vitamin E and carotenoids are known to act as antioxidants both in vitro and in vivo. In this review we present a series of studies in healthy subjects and in patients who exhibit either acute or chronic oxidative stress. In the EU-Commission funded VITAGE project we investigated the status and effects of vitamin E and carotenoids on oxidative stress in 300 healthy volunteers. Depletion studies limiting dietary vitamin E or carotenoid intake to approximately 25% of the dietary reference intakes and subsequent repletion by supplementation with either large doses of vitamin E or intermediate doses of carotenoids showed significant changes in ex vivo LDL oxidizability, total plasma peroxide concentrations and urinary 8-oxo-7,8-dihydro-2(')-deoxyguanosine excretion. Patients on chronic hemodialysis present with oxidative stress in the presence of normal vitamin E but impaired vitamin C status and, due to anemia, need to be treated with parenteral iron. We studied the effects of a single oral dose of vitamin E taken 6 h prior to intravenous infusion of 100 mg iron, which exceeded the iron-binding capacity of transferrin. Vitamin E significantly reduced and in combination with a single dose of vitamin C completely abrogated acute oxidative stress induced by the iron load. Patients with cystic fibrosis are exposed to chronic oxidative stress due to an overproduction of reactive oxygen species as a result of neutrophil-dominated lung inflammation and impaired antioxidant status. Biochemical vitamin E and carotenoid deficiencies could be fully corrected even in the presence of fat malabsorption using intermediate doses of either RRR alpha-tocopherol or all-rac alpha-tocopheryl acetate and water-miscible all-trans beta-carotene. Long-term supplementation reduced ex vivo LDL oxidizability, in vivo lipid peroxidation and lung inflammation.

Vitamin E attenuates oxidative stress induced by intravenous iron in patients on hemodialysis.

Intravenous iron application to anemic patients on hemodialysis leads to an "oversaturation" of transferrin. As a result, non-transferrin-bound, redox-active iron might induce lipid peroxidation. To test the hypothesis that vitamin E attenuates lipid peroxidation in patients receiving 100 mg of iron(III) hydroxide sucrose complex intravenously during a hemodialysis session, 22 patients were investigated in a randomized cross-over design, either with or without a single oral dose of 1200 IU of all-rac-alpha-tocopheryl acetate taken 6 h before the hemodialysis session. Blood was drawn before and 30, 60, 90, 135, and 180 min after the start of the iron infusion, and areas under the curve (AUC0-180 min) of ratios of plasma malondialdehyde (MDA) to cholesterol and plasma total peroxides to cholesterol (two markers of lipid peroxidation) were determined as the outcome variables. At baseline of the session without vitamin E supplementation, plasma alpha-tocopherol concentrations (27.6 +/- 1.8 micromol/L) and ratios of alpha-tocopherol to cholesterol (5.88 +/- 1.09 mmol/mol) were normal, plasma MDA concentrations were above normal (1.20 +/- 0.28 micromol/ L), and bleomycin-detectable iron (BDI), indicating the presence of redox-active iron, was not detectable. Upon iron infusion, BDI and MDA concentrations increased significantly (P < 0.001). BDI concentrations explained the increase over baseline in MDA concentrations (MDA = 1.29 +/- 0.075 x BDI). Vitamin E supplementation, leading to a 68% increase in plasma alpha-tocopherol concentrations, significantly reduced the AUC0-180 min of MDA to cholesterol (P = 0.004) and peroxides to cholesterol (P = 0.002). These data demonstrate that a single oral dose of vitamin E attenuates lipid peroxidation in patients on hemodialysis receiving intravenous iron. Given that intravenous iron is applied repeatedly to patients on hemodialysis, this therapeutic approach may protect against oxidative stress-related degenerative disease in the long term.