The feasibility of a multidimensional intervention in lymphoma survivors with chronic fatigue.

PURPOSE: Chronic fatigue (CF) affects 25-30% of lymphoma survivors, but interventions designed to reduce fatigue are lacking. The main aim of this study was to test the feasibility of a multidimensional intervention study in lymphoma survivors with CF. Secondary aims were to describe individual changes in fatigue, quality of life (QoL) and physical performance from pre (T0) to post (T1) intervention. METHODS: This feasibility study was as a one-armed intervention study performed in 2021. Hodgkin or aggressive non-Hodgkin lymphoma survivors received mailed study information and Chalder Fatigue Questionnaire and were asked to respond if they suffered from fatigue. The 12-week intervention included patient education, physical exercise, a cognitive behavioural therapy (CBT)-based group program and nutritional counselling. Feasibility data included patient recruitment, completion of assessments, adherence to the intervention and patient-reported experience measures. Participants responded to questionnaires and underwent physical tests at T0 and T1. RESULTS: Seven lymphoma survivors with CF were included. Of all assessments, 91% and 83% were completed at T0 and T1, respectively. Adherence to the interventional components varied from 69% to 91%. At T1, all participants rated exercise as useful, of whom five rated the CBT-based program and five rated individual nutritional counselling as useful. Five participants reported improved fatigue, QoL and physical performance. CONCLUSION: Lymphoma survivors with CF participating in a multidimensional intervention designed to reduce the level of fatigue showed high assessment completion rate and intervention adherence rate. Most of the participants evaluated the program as useful and improved their level of fatigue, QoL and physical performance after the intervention. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT04931407. Registered 16. April 2021-Retrospectively registered. https://www. CLINICALTRIALS: gov/ct2/show/NCT04931407.

Antioxidant-rich foods and response to altitude training: A randomized controlled trial in elite endurance athletes.

High doses of isolated antioxidant supplements such as vitamin C and E have demonstrated the potential to blunt cellular adaptations to training. It is, however, unknown whether intake of high doses of antioxidants from foods has similar effects. Hence, the aim of the study was to investigate whether intake of antioxidant-rich foods affects adaptations to altitude training in elite athletes. In a randomized controlled trial, 31 national team endurance athletes (23 ± 5 years) ingested antioxidant-rich foods (n = 16) or eucaloric control foods (n = 15) daily during a 3-week altitude training camp (2320 m). Changes from baseline to post-altitude in hemoglobin mass (Hbmass ; optimized CO rebreathing), maximal oxygen uptake (VO2max ; n = 16) or 100 m swimming performance (n = 10), and blood parameters were compared between the groups. The antioxidant group significantly increased total intake of antioxidant-rich foods (~118%) compared to the control group during the intervention. The total study population improved VO2max by 2.5% (1.7 mL/kg/min, P = .006) and Hbmass by 4.7% (48 g, P < .001), but not 100 m swimming performance. No difference was found between the groups regarding changes in Hbmass , VO2max or swimming performance. However, hemoglobin concentration increased more in the antioxidant group (effect size = 0.7; P = .045) with a concomitantly larger decrease in plasma and blood volumes compared to control group. Changes in ferritin and erythropoietin from pre- to post-altitude did not differ between the groups. Doubling the intake of antioxidant-rich foods was well tolerated and did not negatively influence the adaptive response to altitude training in elite endurance athletes.

A combination of low serum concentrations of vitamins K1 and D is associated with increased risk of hip fractures in elderly Norwegians: a NOREPOS study.

UNLABELLED: The present study investigated the risk of incident hip fractures according to serum concentrations of vitamin K1 and 25-hydroxyvitamin D in elderly Norwegians during long-term follow-up. The results showed that the combination of low concentrations of both vitamin D and K1 provides a significant risk factor for hip fractures. INTRODUCTION: This case-cohort study aims to investigate the associations between serum vitamin K1 and hip fracture and the possible effect of 25-hydroxyvitamin D (25(OH)D) on this association. METHODS: The source cohort was 21,774 men and women aged 65 to 79 years who attended Norwegian community-based health studies during 1994-2001. Hip fractures were identified through hospital registers during median follow-up of 8.2 years. Vitamins were determined in serum obtained at baseline in all hip fracture cases (n = 1090) and in a randomly selected subcohort (n = 1318). Cox proportional hazards regression with quartiles of serum vitamin K1 as explanatory variable was performed. Analyses were further performed with the following four groups as explanatory variable: I: vitamin K1 ≥ 0.76 and 25(OH)D ≥ 50 nmol/l, II: vitamin K1 ≥ 0.76 and 25(OH)D < 50 nmol/l, III: vitamin K1 < 0.76 and 25(OH)D ≥ 50 nmol/l, and IV: vitamin K1 < 0.76 and 25(OH)D < 50 nmol/l. RESULTS: Age- and sex-adjusted analyses revealed an inverse association between quartiles of vitamin K1 and the risk of hip fracture. Further, a 50 % higher risk of hip fracture was observed in subjects with both low vitamin K1 and 25(OH)D compared with subjects with high vitamin K1 and 25(OH)D (HR 1.50, 95 % CI 1.18-1.90). The association remained statistically significant after adjusting for body mass index, smoking, triglycerides, and serum α-tocopherol. No increased risk was observed in the groups low in one vitamin only. CONCLUSION: Combination of low concentrations of vitamin K1 and 25(OH)D is associated with increased risk of hip fractures.

Vitamin C and E supplementation blunts increases in total lean body mass in elderly men after strength training.

The aim of this study was to investigate the effects of vitamin C and E supplementation on changes in muscle mass (lean mass and muscle thickness) and strength during 12 weeks of strength training in elderly men. Thirty-four elderly males (60-81 years) were randomized to either an antioxidant group (500 mg of vitamin C and 117.5 mg vitamin E before and after training) or a placebo group following the same strength training program (three sessions per week). Body composition was assessed with dual-energy X-ray absorptiometry and muscle thickness by ultrasound imaging. Muscle strength was measured as one-repetition maximum (1RM). Total lean mass increased by 3.9% (95% confidence intervals: 3.0, 5.2) and 1.4% (0, 5.4) in the placebo and antioxidant groups, respectively, revealing larger gains in the placebo group (P = 0.04). Similarly, the thickness of m. rectus femoris increased more in the placebo group [16.2% (12.8, 24.1)] than in the antioxidant group [10.9% (9.8, 13.5); P = 0.01]. Increases of lean mass in trunk and arms, and muscle thickness of elbow flexors, did not differ significantly between groups. With no group differences, 1RM improved in the range of 15-21% (P < 0.001). In conclusion, high-dosage vitamin C and E supplementation blunted certain muscular adaptations to strength training in elderly men.

Low serum concentrations of alpha-tocopherol are associated with increased risk of hip fracture. A NOREPOS study.

UNLABELLED: We investigated the risk of hip fracture according to circulating alpha-tocopherol, a plant-derived substance with antioxidant properties, in community-dwelling older Norwegians. We found a linear increasing risk of hip fracture with lower serum alpha-tocopherol concentrations, with a 51% higher risk in the lowest compared to the highest quartile. INTRODUCTION: Oxidative stress is a suggested contributing cause of osteoporosis and fractures. Vitamin E (α-tocopherol) has potent antioxidant properties in humans. The relationship between circulating α-tocopherol and fracture risk is not established. The aim of this study was to investigate the association between serum α-tocopherol concentrations and risk of hip fracture during up to 11 years of follow-up. METHODS: We performed a case-cohort analysis among 21,774 men and women aged 65-79 years who participated in four community-based health studies in Norway 1994-2001. Serum α-tocopherol concentrations at baseline were determined in 1,168 men and women who subsequently suffered hip fractures (median follow-up 8.2 years) and in a random sample (n = 1,434) from the same cohort. Cox proportional hazard regression adapted for gender-stratified case-cohort data was performed. RESULTS: Median (25, 75 percentile) serum α-tocopherol was 30.0 (22.6, 38.3) µmol/L, and it showed a linear inverse association with hip fracture: hazard ratio (HR) 1.11 (95% confidence interval (CI) 1.04-1.20) per 10-µmol/L decrease in serum α-tocopherol, adjusted for gender and study center. The lowest compared to the highest quartile conferred an HR of 1.51 (95% CI 1.17-1.95), adjusted for gender and study center. Adjustment for smoking, month of blood sample, BMI, education, physical inactivity, self-rated health, and serum 25-hydroxyvitamin D (25(OH)D) yielded similar results. Taking serum total cholesterol concentration into account attenuated the association somewhat: HR of hip fracture was 1.37 (95% CI 1.05-1.77) in first versus fourth quartile of serum α-tocopherol/total cholesterol ratio. CONCLUSIONS: Low serum concentrations of α-tocopherol were associated with increased risk of hip fracture in older Norwegians.

Apo-10'-lycopenoic acid impacts adipose tissue biology via the retinoic acid receptors.

Apo-10'-lycopenoic acid (apo-10-lycac), a metabolite of lycopene, has been shown to possess potent biological activities, notably via the retinoic acid receptors (RAR). In the current study, its impact on adipose tissue and adipocytes was studied. In microarray experiments, the set of genes regulated by apo-10-lycac treatments was compared to the set of genes regulated by all-trans retinoic acid (ATRA), the natural ligand of RAR, in adipocytes. Approximately 27.5% of the genes regulated by apo-10-lycac treatments were also regulated by ATRA, suggesting a common ability in terms of gene expression modulation, possibly via RAR transactivation. The physiological impact of apo-10-lycac on adipose tissue biology was evaluated. If it had no effect on adipogenesis in the 3T3-L1 cell model, this metabolite may have a preventative effect against inflammation, by preventing the increase in the inflammatory markers, interleukin 6 and interleukin 1ß in various dedicated models. The ability of apo-10-lycac to transactivate the RAR and to modulate the transcription of RAR target gene was brought in vivo in adipose tissue. While apo-10-lycac was not detected in adipose tissue, a metabolite with a molecular weight with 2Da larger mass was detected, suggesting that a dihydro-apo-10'-lycopenoic acid, may be present in adipose tissue and that this compound could active or may lead to further active RAR-activating apo-10-lycac metabolites. Since apo-10-lycac treatments induce anti-inflammatory effects in adipose tissue but do not inhibit adipogenesis, we propose that apo-10-lycac treatments and its potential active metabolites in WAT may be considered for prevention strategies relevant for obesity-associated pathologies.

Plasma antioxidant responses and oxidative stress following a soccer game in elite female players.

We aimed to investigate markers of oxidative stress and levels of endogenous and dietary antioxidants in 16 elite female soccer players in response to a 90-min game (average intensity 82+/-3% HRpeak). Blood samples were taken before, immediately and 21 h after the game. Plasma-oxidized glutathione, the ratio of reduced to oxidized glutathione (GSH:GSSG) and lipid peroxidation measured by d-ROMs were used as markers of oxidative stress. Plasma endogenous [uric acid, total glutathione (TGSH)] and dietary antioxidants (alpha-tocopherol, ascorbic acid, total carotenoids and polyphenols) were analyzed using liquid chromatography and the Folin-Ciocalteu method. Exercise induced an acute increase (P<0.05) in GSSG, uric acid, TGSH, alpha-tocopherol, and ascorbic acid. In parallel, the GSH:GSSG ratio and polyphenols decreased (P<0.05). GSSG, GSH:GSSG ratio, uric acid, TGSH, and ascorbic acid returned to baseline at 21 h, while polyphenols and alpha-tocopherol remained altered. Total carotenoids increased above baseline only at 21 h (P<0.05). Lipid peroxidation, measured by d-ROMs, remained unchanged throughout the study. Thus, intermittent exercise in well-trained female athletes induces a transient increase in GSSG and a decrease in the GSH:GSSG ratio, which is effectively balanced by the recruitment of both endogenous and dietary antioxidants, resulting in the absence of lipid peroxidation measured by d-ROMs.

Differences in the inflammatory plasma cytokine response following two elite female soccer games separated by a 72-h recovery.

We investigated changes in a large battery of pro- and anti-inflammatory cytokines in elite female soccer players following two 90-min games separated by a 72-h active or passive recovery. Blood samples were taken from 10 players before, within 15-20 min, 21, 45 and 69 h after the first game and within 15-20 min after the second game. The leukocyte count was analyzed, together with several plasma pro- and anti-inflammatory cytokines, using a multiplex bead array system. After the first and second game, the total leukocytes and neutrophils increased significantly. Likewise, increases (P<0.05) in pro-inflammatory cytokines [interleukin (IL)-12, tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ), IL-17], chemokines [monocyte chemotactic protein-1 (MCP-1), IL-8 and monokine induced by gamma interferon (MIG)], anti-inflammatory cytokines (IL-2R, IL-4, IL-5, IL-7, IL-10, IL-13, INF-α) and the mixed cytokine IL-6 were observed. Leukocyte and cytokine levels were normalized within 21 h. Active recovery (low-intensity exercises) did not affect the cytokine responses. A dampened cytokine response was observed after the second game as only IL-12, IL-6, MCP-1, IL-8 and MIG increased (P<0.05). In conclusion, a robust pro- and anti-inflammatory cytokine response occurs after the first but not the second soccer game. The implications of the dampened cytokine response in female players after the second game are unknown.

Transport and storage of vitamin A.

The requirement of vitamin A (retinoids) for vision has been recognized for decades. In addition, vitamin A is involved in fetal development and in the regulation of proliferation and differentiation of cells throughout life. This fat-soluble organic compound cannot be synthesized endogenously by humans and thus is an essential nutrient; a well-regulated transport and storage system provides tissues with the correct amounts of retinoids in spite of normal fluctuations in daily vitamin A intake. An overview is presented here of current knowledge and hypotheses about the absorption, transport, storage, and metabolism of vitamin A. Some information is also presented about a group of ligand-dependent transcription factors, the retinoic acid receptors, that apparently mediate many of the extravisual effects of retinoids.

Extracts of dietary plants are efficient modulators of nuclear factor kappa B.

Convincing evidence suggest that a plant-based diet is associated with a reduced risk of several chronic diseases, but the mechanisms for this association is not fully elucidated. The transcription factor nuclear factor kappa B (NF-kappa B) plays a critical role in cellular stress-, immune- and inflammatory responses. Also, NF-kappa B is identified as a promising therapeutic target both in cancer and chronic inflammation. We used monocytes stably transfected with a NF-kappa B-luciferase reporter construct in a screening of plant extracts for NF-kappa B modulators. Our aim was to identify dietary components which could induce basal NF-kappa B activity to produce a preconditioning effect, or inhibit induction of disease related NF-kappa B activity. When screening 34 dietary plants for their ability to induce basal NF-kappa B activity or inhibit lipopolysaccharide induced NF-kappa B activity we observed that 23 dietary plant extracts induced basal NF-kappa B activity, while 15 extracts attenuate induced NF-kappa B activation. These results indicate that dietary plants contain compounds that efficiently modulate NF-kappa B activity. We suggest dietary modulation of NF-kappa B may contribute to the observed beneficial effects of dietary plants on the risk of chronic diseases.

Lutein prevents the effect of high glucose levels on immune system cells in vivo and in vitro.

Diabetic patients present an increased susceptibility to frequent and protracted infections. The recognition of an impaired immune system has implications for the diagnosis, treatment and outcome of infections. Nuclear Factor kappa B (NF-kappaB) is a redox sensitive transcription factor involved in immune response, cell proliferation and apoptosis that has been associated to the development of diabetic complications. Herein we study the effects of high glucose on oxidative stress markers (malondialdeyde and glutathione contents) and NF-kappaB activity in U937 cells (a human promonocytic cell line). Furtheremore effects of lutein treatment in lymphocytes from diabetic rats was studied. The results show that high glucose induces oxidative stress in immune system cells, both in vitro and in vivo, as well as an increase in their NF-kappaB activity. It is also showed that lutein, a natural antioxidant without hypoglycemiant properties, is able to prevent all the alterations observed. Thus, this study confirms the role of oxidative stress in the immune system impairment described in diabetes, and allows the proposal of antioxidants for the clinical management of the diabetes-associated susceptibility to infections.

Stability of whole blood and plasma ascorbic acid.

The objective of this study was to evaluate the impact of pre-analytical factors on the short and long term stability of ascorbic acid (AA), the main form of vitamin C in whole blood and plasma. The effects of various anticoagulants, acidification, storage temperature and time were tested. A recently developed fast and sensitive HPLC method was used to measure AA levels. AA baseline values observed in heparin plasma were significantly higher than values observed in EDTA, citrate and Stabilyte plasma, as well as in serum. pH and temperature were identified as additional critical pre-analytical factors during the short, medium and long term handling and storage. Thus, assessment of reliable and accurate AA status in biological samples demonstrates to be highly dependent on whether the initial conditions during sample handling are controlled. In conclusion, heparin tubes should be used for blood sample collection. As AA is rapidly degraded, sample collection should be followed by immediate centrifugation and plasma acidification. To avoid further degradation during sample handling, samples should be stored at -70 degrees C without delay and analyzed within 80 days.

The effect of an increased intake of vegetables and fruit on weight loss, blood pressure and antioxidant defense in subjects with sleep related breathing disorders.

OBJECTIVE: To assess the effect of an increased consumption of vegetables and fruit on body weight, risk factors for cardiovascular disease (CVD) and antioxidant defense in obese patients with sleep-related breathing disorders (SRBD). DESIGN: Randomized, controlled trial of an intervention to increase the intake of vegetables to 400 g/day and fruit to 300 g/day. Dietary intake was calculated from a food frequency questionnaire. Antioxidant status was assessed with the ferric-reducing/antioxidant power (FRAP) assay. Plasma carotenoids were biomarkers for the intake of vegetables and fruit. SETTING: A hospital clinic preventing risk factors for CVD. SUBJECTS: Subjects were 103 men and 35 women with a body mass index of 36.7+/-5.8 kg/m(2) of which 57 (86%) in the control and 68 (94%) in the intervention group completed the study. INTERVENTION: Group-based behavioral program during 3 months. RESULTS: The mean between group differences in body weight was -2.0% (95% CI -3.6, -0.5), P<0.0001. The mean between group difference in systolic and diastolic blood pressure (BP) was -7.1 mm Hg (95% CI: -11.6, -2.6), P=0.0022 and -3.9 mm Hg (95% CI: -7.0, -0.9), P=0.0120, respectively. The mean change in daily intake of vegetables and fruit was 12 g (95% CI: -33, 57) and -4 g (95% CI: -79, 71) versus 245 g (95% CI: 194, 296) and 248 g (95% CI: 176, 320) in the control and intervention groups, respectively. This was reflected in higher concentrations of alpha-carotene and beta-carotene. No change in FRAP was seen. In a multiple regression analysis the change in intake of vegetables was a significant contributor (R(adj)(2)=0.073 (95% CI: 0.019, 0.214)) to the change in weight. CONCLUSION: Targeted dietary advice to increase the intake of vegetables and fruit among subjects with SRBD contributed to weight reduction and reduced systolic and diastolic BP, but had no effect on antioxidant defense measured with FRAP.

A low proportion of malnourished patients receive nutrition treatment - results from nutritionDay.

NutritionDay is a yearly point-prevalence study of malnutrition in hospitals from more than 50 countries. The aim of the present study was to quantify the frequency of malnutrition and the proportion of malnourished patients receiving nutritional treatment in two university hospitals in Norway using data from nutritionDay. All units at Oslo University Hospital (OUH) and University Hospital of Northern Norway (UNN) were invited to participate in nutritionDay 2014, and 28 out of 85 eligible units agreed to take part. Malnutrition was diagnosed based on body mass index (BMI), weight reduction and food intake in the previous week, according to national guidelines and ESPEN criteria. Data from 488 patients were available, representing 90.1% of occupied beds in participating units. Thirty percent of the patients were diagnosed malnourished when national criteria were used, and only 41% of these patients received nutritional treatment. The estimated malnutrition rate was 11% when the ESPEN consensus criteria were used. Data on weight or height were frequently missing in the patient records, and BMI could only be calculated in two-thirds of the patients. The frequency of low BMI (<18.5 kg/m2) was only 5%. Involuntary weight loss was present in 37% of the patients, and 60% had eaten less than normal in the previous week. Oncology units had the highest frequency of patients with low BMI, and the highest weight loss and overall malnutrition rate. Surgery and geriatric units had the highest rate of patients with low food intake. In this study, nearly 60% of the malnourished patients did not receive any nutritional treatment, and this indicates a potential for improved nutritional care and cost savings. Low food intake and weight loss were frequent at these two Norwegian hospitals, and in line with previous reports from nutritionDay in other countries.

Enhanced stability of beta-galactosidase in parenchymal and nonparenchymal liver cells by conjugation with dextran.

In order to enhance the stability of beta-galactosidase, we conjugated the enzyme with dextran T-10 (Mr approx. 10 000). The conjugate contained 9-10 mol dextran/mol protein (beta-galactosidase, Mr 68 000), and the specific activity retained after conjugation was 90 +/- 4% (n = 3) of the initial activity. Uptake and degradation of native and conjugated beta-galactosidase in isolated hepatocytes and nonparenchymal liver cells was studied. There was a marked increase in stability against degradation in both cell types when beta-galactosidase was conjugated with Dextran. The degradation of dextran-conjugated enzyme was reduced by 35% in hepatocytes and by 43% in nonparenchymal cells, after 80 and 40 min, respectively, as compared with the free enzyme. However, there was insignificant difference between the uptake of native and conjugated enzyme into the liver cells. Upon intravenous infusion into rats, native and conjugated enzyme were cleared from plasma with only a slight difference in the clearance rate. The observed stability of dextran-conjugated beta-galactosidase towards cellular degradation was in accordance with the in vitro experiments. The conjugate showed marked thermal stability at 50 degrees C and enhanced resistance towards proteolysis by the broad specific protease subtilopeptidase A. This demonstrates that dextran conjugation may be used as a means of stabilizing lysosomal enzymes for therapeutic purposes.

The effect of retinoids and clofibric acid on the peroxisomal oxidation of palmitic acid and of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid in rat and rabbit hepatocytes.

The effects of retinoids and the peroxisome proliferator clofibric acid on peroxisomal enzyme pathways were studied in hepatocytes from both rat and rabbit. Retinoic acid and retinol increased the activity of acyl-CoA oxidase in rabbit hepatocytes around 60% and around 30% in rat hepatocytes. Exposure to clofibric acid caused an increase in acyl-CoA oxidase activity of 115% in rat hepatocytes and of 40% in rabbit hepatocytes, indicating that rabbit is less sensitive to peroxisome proliferator than rat. Simultaneous exposure to clofibric acid and retinoids did not act additatively or synergistically. Both rabbit and rat hepatocytes expressed mRNA for the peroxisome proliferator activated receptor, (PPAR), although the transcript in rabbit was slightly smaller compared to that expressed in rat hepatocytes. The effect of retinoic acid in 7800 C1 Morris rat hepatoma cells, a cell line known to have an inducible peroxisomal beta-oxidation of fatty acids, was only slight with an increase of the acyl-CoA oxidase activity of 25% compared with control cells. As for clofibric acid, which gave a 2-fold induction of the acyl-CoA oxidase activity, the effect of retinoic acid was potentiated by dexamethasone. These cells also expressed mRNA for PPAR, with the same size as that found in rat hepatocytes. The oxidation of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid (THCA), an intermediate in bile acid formation, in rat hepatocytes increased 110% by clofibric acid and around 80% by retinoic acid. In rabbit hepatocytes, clofibric acid increased the oxidation rate 75% and retinoic acid 100%. The results presented here show similarities in the effects of retinoids and clofibric acid on the acyl-CoA oxidase activity and the oxidation rate of THCA, since they increase these two peroxisomal activities in hepatocytes in vitro. A decrease in both these enzyme activities occurs during cultivation time in untreated primary hepatocyte cultures. The present data may therefore either be explained by an increased expression or an induced stability of the enzymes involved.

Intracellular transport and degradation of chylomicron remnants in rat liver cells after in vivo endocytosis.

The intracellular transport and degradation of in vivo endocytosed chylomicron remnants labelled with 125I in the protein moiety was studied in rat liver cells by means of subcellular fractionation in Nycodenz and sucrose density gradients. Initially, the radioactivity was located in low-density endosomes and was sequentially transferred to light and dense lysosomes. Data from gel filtration of the light and dense lysosomal fractions showed radioactive material with a molecular weight of about 1000-2000, representing short peptide fragments or amino acids which remain attached to iodinated tyramine cellobiose. In addition, undegraded apoproteins accumulated in both types of lysosome. Our data suggest that endocytosed chylomicron remnant apoproteins are first located in low-density endosomes and are sequentially transferred to light and dense lysosomes. Furthermore, the degradation process starts in the light lysosomes.

Lymphatic absorption and transport of retinol and vitamin D-3 from rat intestine. Evidence for different pathways.

The lymphatic absorption and transport of retinol and vitamin D-3 from rat intestine has been studied. When rats were cannulated in the intestinal lymph duct and given an intraduodenal bolus of [3H]retinol and 14C-labelled vitamin D-3, 14C-labeled vitamin D-3 appeared later in the intestinal lymph than [3H]retinol and the rate of absorption of vitamin D-3 was still maximal at a time when that of retinol had declined. Both vitamins were absorbed via the lymphatic route in association with chylomicrons. Almost all the retinol was esterified, while vitamin D-3 appeared in the chylomicrons as free vitamin D-3. In vitro incubations and in vivo studies using hepatectomized and normal rats showed that the retinyl ester was a relatively nonexchangeable component of the chylomicrons and their remnants. Hence, all the vitamin A followed the remnants in their clearance from plasma. In contrast, significant amounts of vitamin D-3 were transferred from the chylomicrons to other plasma fractions. Therefore, only a fraction of this vitamin may be removed in association with the chylomicron remnants.

TCF11/Nrf1 overexpression increases the intracellular glutathione level and can transactivate the gamma-glutamylcysteine synthetase (GCS) heavy subunit promoter.

Gamma-glutamylcysteinylglycine or glutathione (GSH) performs important protective functions in the cell through maintenance of the intracellular redox balance and elimination of xenobiotics and free radicals. The production of GSH involves a number of enzymes and enzyme subunits offering multiple opportunities for regulation. Two members of the CNC subfamily of bZIP transcription factors (TCF11/Nrf1 and Nrf2) have been implicated in the regulation of detoxification enzymes and the oxidative stress response. Here we investigate the potential role of one of these factors, TCF11/Nrf1, in the regulation of GSH levels in the cell and particularly its influence on the expression of one of the enzymatic components necessary for the synthesis of GSH, the heavy subunit of gamma-glutamylcysteine synthetase (GCS(h)). Using overexpression of the transcription factor in COS-1 cells we show that TCF11/Nrf1 stimulates GSH accumulation. Using co-transfection with reporter constructs where reporter expression is driven through the GCS(h) promoter we show that this increase may be mediated in part by induced expression of the GCS(h) gene by TCF11/Nrf1. We further show that a distal portion of the promoter including two antioxidant-response elements (AREs) predominantly mediates the TCF11/Nrf1 transactivation and an electromobility shift assay showed that just one of these AREs specifically binds TCF11/Nrf1 as heterodimers with small Maf proteins. We suggest that TCF11/Nrf1 can operate through a subset of AREs to modulate the expression of GCS(h) together with other components of the pathway and in this way play a role in regulating cellular glutathione levels.

A robust characterization of retinoic acid response elements based on a comparison of sites in three species.

The availability of high-throughput genomic sequencing has allowed us to construct a more robust characterization of retinoic acid response elements than was possible in the past. We located human, mouse, and rat homologs for each of 51 well-documented, conserved retinoic acid response elements. Mathematical and statistical analyses of these 153 sites, 78 of which are new, shows that 92% of response elements have direct-repeat symmetry, but that only 76% exhibit canonical spacing attributes. While the familiar '(a/g)g(g/t)tca' hexamer motif is upheld, the more relaxed sequence, '(a/g)g(g/t)(g/t)(g/c)a', represents a 10% consensus. Sites are as likely to be on the coding strand as on the non-coding strand, and 86% of them are in upstream locations. From a statistical point of view, DR1 elements are fundamentally different from DR2 and DR5 elements, but this is only evident in the 5' hexamer. While there is considerable variation in core positions, and while no nucleotide can be considered forbidden at any position, variation among species at a fixed locus appears surprisingly constrained once a functional site has been attained.