109 research outputs found

    Inorganic Nitrate Promotes Glucose Uptake and Oxidative Catabolism in White Adipose Tissue through the XOR Catalyzed Nitric Oxide Pathway

    Get PDF
    An ageing global population combined with sedentary lifestyles and unhealthy diets has contributed to an increasing incidence of obesity and type 2 diabetes. These metabolic disorders are associated with perturbations to nitric oxide (NO) signaling and impaired glucose metabolism. Dietary inorganic nitrate, found in high concentration in green leafy vegetables, can be converted to NO in vivo and demonstrates anti-diabetic and anti-obesity properties in rodents. Alongside tissues including skeletal muscle and liver, white adipose tissue is also an important physiological site of glucose disposal. However, the distinct molecular mechanisms governing the effect of nitrate on adipose tissue glucose metabolism, and the contribution of this tissue to the glucose tolerant phenotype, remain to be determined. Using a metabolomic and stable-isotope labeling approach, combined with transcriptional analysis, we found that nitrate increases glucose uptake and oxidative catabolism in primary adipocytes and white adipose tissue of nitrate-treated rats. Mechanistically, we determine that nitrate induces these phenotypic changes in primary adipocytes through the xanthine oxidoreductase catalysed reduction of nitrate to nitric oxide and independently of Peroxisome Proliferator-Activated Receptor α. The nitrate-mediated enhancement of glucose uptake and catabolism in white adipose tissue may be a key contributor to the anti-diabetic effects of this anion

    Divergent trajectories of cellular bioenergetics, intermediary metabolism and systemic redox status in survivors and non-survivors of critical illness.

    Get PDF
    BACKGROUND: Numerous pathologies result in multiple-organ failure, which is thought to be a direct consequence of compromised cellular bioenergetic status. Neither the nature of this phenotype nor its relevance to survival are well understood, limiting the efficacy of modern life-support. METHODS: To explore the hypothesis that survival from critical illness relates to changes in cellular bioenergetics, we combined assessment of mitochondrial respiration with metabolomic, lipidomic and redox profiling in skeletal muscle and blood, at multiple timepoints, in 21 critically ill patients and 12 reference patients. RESULTS: We demonstrate an end-organ cellular phenotype in critical illness, characterized by preserved total energetic capacity, greater coupling efficiency and selectively lower capacity for complex I and fatty acid oxidation (FAO)-supported respiration in skeletal muscle, compared to health. In survivors, complex I capacity at 48 h was 27% lower than in non-survivors (p = 0.01), but tended to increase by day 7, with no such recovery observed in non-survivors. By day 7, survivors' FAO enzyme activity was double that of non-survivors (p = 0.048), in whom plasma triacylglycerol accumulated. Increases in both cellular oxidative stress and reductive drive were evident in early critical illness compared to health. Initially, non-survivors demonstrated greater plasma total antioxidant capacity but ultimately higher lipid peroxidation compared to survivors. These alterations were mirrored by greater levels of circulating total free thiol and nitrosated species, consistent with greater reductive stress and vascular inflammation, in non-survivors compared to survivors. In contrast, no clear differences in systemic inflammatory markers were observed between the two groups. CONCLUSION: Critical illness is associated with rapid, specific and coordinated alterations in the cellular respiratory machinery, intermediary metabolism and redox response, with different trajectories in survivors and non-survivors. Unravelling the cellular and molecular foundation of human resilience may enable the development of more effective life-support strategies

    A randomized 3-way crossover study indicates that high-protein feeding induces de novo lipogenesis in healthy humans

    Get PDF
    BACKGROUND. Dietary changes have led to the growing prevalence of type 2 diabetes and nonalcoholic fatty liver disease. A hallmark of both disorders is hepatic lipid accumulation, derived in part from increased de novo lipogenesis. Despite the popularity of high-protein diets for weight loss, the effect of dietary protein on de novo lipogenesis is poorly studied. We aimed to characterize the effect of dietary protein on de novo lipid synthesis. METHODS. We use a 3-way crossover interventional study in healthy males to determine the effect of high-protein feeding on de novo lipogenesis, combined with in vitro models to determine the lipogenic effects of specific amino acids. The primary outcome was a change in de novo lipogenesis–associated triglycerides in response to protein feeding. RESULTS. We demonstrate that high-protein feeding, rich in glutamate, increases de novo lipogenesis–associated triglycerides in plasma (1.5-fold compared with control; P < 0.0001) and liver-derived very low-density lipoprotein particles (1.8-fold; P < 0.0001) in samples from human subjects (n = 9 per group). In hepatocytes, we show that glutamate-derived carbon is incorporated into triglycerides via palmitate. In addition, supplementation with glutamate, glutamine, and leucine, but not lysine, increased triglyceride synthesis and decreased glucose uptake. Glutamate, glutamine, and leucine increased activation of protein kinase B, suggesting that induction of de novo lipogenesis occurs via the insulin signaling cascade. CONCLUSION. These findings provide mechanistic insight into how select amino acids induce de novo lipogenesis and insulin resistance, suggesting that high-protein feeding to tackle diabetes and obesity requires greater consideration. FUNDING. The research was supported by UK Medical Research Council grants MR/P011705/1, MC_ UP_A090_1006 and MR/P01836X/1. JLG is supported by the Imperial Biomedical Research Centre, National Institute for Health Research (NIHR)

    Narrative exposure therapy for PTSD increases top-down processing of aversive stimuli - evidence from a randomized controlled treatment trial

    Get PDF
    Adenauer H, Catani C, Gola H, et al. Narrative exposure therapy for PTSD increases top-down processing of aversive stimuli - evidence from a randomized controlled treatment trial. BMC Neuroscience. 2011;12(1): 127.BACKGROUND: Little is known about the neurobiological foundations of psychotherapy for Posttraumatic Stress Disorder (PTSD). Prior studies have shown that PTSD is associated with altered processing of threatening and aversive stimuli. It remains unclear whether this functional abnormality can be changed by psychotherapy. This is the first randomized controlled treatment trial that examines whether narrative exposure therapy (NET) causes changes in affective stimulus processing in patients with chronic PTSD. METHODS: 34 refugees with PTSD were randomly assigned to a NET group or to a waitlist control (WLC) group. At pre-test and at four-months follow-up, the diagnostics included the assessment of clinical variables and measurements of neuromagnetic oscillatory brain activity (steady-state visual evoked fields, ssVEF) resulting from exposure to aversive pictures compared to neutral pictures. RESULTS: PTSD as well as depressive symptom severity scores declined in the NET group, whereas symptoms persisted in the WLC group. Only in the NET group, parietal and occipital activity towards threatening pictures increased significantly after therapy. CONCLUSIONS: Our results indicate that NET causes an increase of activity associated with cortical top-down regulation of attention towards aversive pictures. The increase of attention allocation to potential threat cues might allow treated patients to re-appraise the actual danger of the current situation and, thereby, reducing PTSD symptoms. REGISTRATION OF THE CLINICAL TRIAL: Number: NCT00563888Name: "Change of Neural Network Indicators Through Narrative Treatment of PTSD in Torture Victims" ULR: http://www.clinicaltrials.gov/ct2/show/NCT00563888

    Evaluating a selective prevention programme for binge drinking among young adolescents: study protocol of a randomized controlled trial

    Get PDF
    Contains fulltext : 99319.pdf (publisher's version ) (Open Access)Background In comparison to other Europe countries, Dutch adolescents are at the top in drinking frequency and binge drinking. A total of 75% of the Dutch 12 to 16 year olds who drink alcohol also engage in binge drinking. A prevention programme called Preventure was developed in Canada to prevent adolescents from binge drinking. This article describes a study that aims to assess the effects of this selective school-based prevention programme in the Netherlands. Methods A randomized controlled trial is being conducted among 13 to 15-year-old adolescents in secondary schools. Schools were randomly assigned to the intervention and control conditions. The intervention condition consisted of two 90 minute group sessions, carried out at the participants' schools and provided by a qualified counsellor and a co-facilitator. The intervention targeted young adolescents who demonstrated personality risk for alcohol abuse. The group sessions were adapted to four personality profiles. The control condition received no further intervention above the standard substance use education sessions provided in the Dutch national curriculum. The primary outcomes will be the percentage reduction in binge drinking, weekly drinking and drinking-related problems after three specified time periods. A screening survey collected data by means of an Internet questionnaire. Students have completed, or will complete, a post-treatment survey after 2, 6, and 12 months, also by means of an online questionnaire. Discussion This study protocol presents the design and current implementation of a randomized controlled trial to evaluate the effectiveness of a selective alcohol prevention programme. We expect that a significantly lower number of adolescents will binge drink, drink weekly, and have drinking-related problems in the intervention condition compared to the control condition, as a result of this intervention.9 p

    Comparative Live-Cell Imaging Analyses of SPA-2, BUD-6 and BNI-1 in Neurospora crassa Reveal Novel Features of the Filamentous Fungal Polarisome

    Get PDF
    A key multiprotein complex involved in regulating the actin cytoskeleton and secretory machinery required for polarized growth in fungi, is the polarisome. Recognized core constituents in budding yeast are the proteins Spa2, Pea2, Aip3/Bud6, and the key effector Bni1. Multicellular fungi display a more complex polarized morphogenesis than yeasts, suggesting that the filamentous fungal polarisome might fulfill additional functions. In this study, we compared the subcellular organization and dynamics of the putative polarisome components BUD-6 and BNI-1 with those of the bona fide polarisome marker SPA-2 at various developmental stages of Neurospora crassa. All three proteins exhibited a yeast-like polarisome configuration during polarized germ tube growth, cell fusion, septal pore plugging and tip repolarization. However, the localization patterns of all three proteins showed spatiotemporally distinct characteristics during the establishment of new polar axes, septum formation and cytokinesis, and maintained hyphal tip growth. Most notably, in vegetative hyphal tips BUD-6 accumulated as a subapical cloud excluded from the Spitzenkörper (Spk), whereas BNI-1 and SPA-2 partially colocalized with the Spk and the tip apex. Novel roles during septal plugging and cytokinesis, connected to the reinitiation of tip growth upon physical injury and conidial maturation, were identified for BUD-6 and BNI-1, respectively. Phenotypic analyses of gene deletion mutants revealed additional functions for BUD-6 and BNI-1 in cell fusion regulation, and the maintenance of Spk integrity. Considered together, our findings reveal novel polarisome-independent functions of BUD-6 and BNI-1 in Neurospora, but also suggest that all three proteins cooperate at plugged septal pores, and their complex arrangement within the apical dome of mature hypha might represent a novel aspect of filamentous fungal polarisome architecture

    Temperament and parental child-rearing style: unique contributions to clinical anxiety disorders in childhood

    Full text link
    Both temperament and parental child-rearing style are found to be associated with childhood anxiety disorders in population studies. This study investigates the contribution of not only temperament but also parental child-rearing to clinical childhood anxiety disorders. It also investigates whether the contribution of temperament is moderated by child-rearing style, as is suggested by some studies in the general population. Fifty children were included (25 with anxiety disorders and 25 non-clinical controls). Child-rearing and the child’s temperament were assessed by means of parental questionnaire (Child Rearing Practices Report (CRPR) (Block in The Child-Rearing Practices Report. Institute of Human Development. University of California, Berkely, 1965; The Child-Rearing Practices Report (CRPR): a set of Q items for the description of parental socialisation attitudes and values. Unpublished manuscript. Institute of Human Development. University of California, Berkely, 1981), EAS Temperament Survey for Children (Boer and Westenberg in J Pers Assess 62:537–551, 1994; Buss and Plomin in Temperament: early developing personality traits. Lawrence Erlbaum Associates, Inc, Hillsdale, 1984s). Analysis of variance showed that anxiety-disordered children scored significantly higher on the temperamental characteristics emotionality and shyness than non-clinical control children. Hierarchical logistic regression analyses showed that temperament (emotionality and shyness) and child-rearing style (more parental negative affect, and less encouraging independence of the child) both accounted for a unique proportion of the variance of anxiety disorders. Preliminary results suggest that child-rearing style did not moderate the association between children’s temperament and childhood anxiety disorders. The limited sample size might have been underpowered to assess this interaction
    corecore