Davidson S.,University of Aberdeen |
Lear M.,University of Aberdeen |
Shanley L.,University of Aberdeen |
Hing B.,University of Aberdeen |
And 8 more authors.
Neuropsychopharmacology | Year: 2011
The expression of the galanin gene (GAL) in the paraventricular nucleus (PVN) and in the amygdala of higher vertebrates suggests the requirement for highly conserved, but unidentified, regulatory sequences that are critical to allow the galanin gene to control alcohol and fat intake and modulate mood. We used comparative genomics to identify a highly conserved sequence that lay 42 kb 5′ of the human GAL transcriptional start site that we called GAL5.1. GAL5.1 activated promoter activity in neurones of the PVN, arcuate nucleus and amygdala that also expressed the galanin peptide. Analysis in neuroblastoma cells demonstrated that GAL5.1 acted as an enhancer of promoter activity after PKC activation. GAL5.1 contained two polymorphisms; rs2513280(C/G) and rs2513281(A/G), that occurred in two allelic combinations (GG or CA) where the dominant GG alelle occurred in 70-83 % of the human population. Intriguingly, both SNPs were found to be in LD (R 2 of 0.687) with another SNP (rs2156464) previously associated with major depressive disorder (MDD). Recreation of these alleles in reporter constructs and subsequent magnetofection into primary rat hypothalamic neurones showed that the CA allele was 40 % less active than the GG allele. This is consistent with the hypothesis that the weaker allele may affect food and alcohol preference. The linkage of the SNPs analysed in this study with a SNP previously associated with MDD together with the functioning of GAL5.1 as a PVN and amygdala specific enhancer represent a significant advance in our ability to understand alcoholism, obesity and major depressive disorder. © 2011 American College of Neuropsychopharmacology. All rights reserved.
Lawley T.D.,Wellcome Trust Sanger Institute |
Clare S.,Wellcome Trust Sanger Institute |
Walker A.W.,Wellcome Trust Sanger Institute |
Stares M.D.,Wellcome Trust Sanger Institute |
And 13 more authors.
PLoS Pathogens | Year: 2012
Relapsing C. difficile disease in humans is linked to a pathological imbalance within the intestinal microbiota, termed dysbiosis, which remains poorly understood. We show that mice infected with epidemic C. difficile (genotype 027/BI) develop highly contagious, chronic intestinal disease and persistent dysbiosis characterized by a distinct, simplified microbiota containing opportunistic pathogens and altered metabolite production. Chronic C. difficile 027/BI infection was refractory to vancomycin treatment leading to relapsing disease. In contrast, treatment of C. difficile 027/BI infected mice with feces from healthy mice rapidly restored a diverse, healthy microbiota and resolved C. difficile disease and contagiousness. We used this model to identify a simple mixture of six phylogenetically diverse intestinal bacteria, including novel species, which can re-establish a health-associated microbiota and clear C. difficile 027/BI infection from mice. Thus, targeting a dysbiotic microbiota with a defined mixture of phylogenetically diverse bacteria can trigger major shifts in the microbial community structure that displaces C. difficile and, as a result, resolves disease and contagiousness. Further, we demonstrate a rational approach to harness the therapeutic potential of health-associated microbial communities to treat C. difficile disease and potentially other forms of intestinal dysbiosis. © 2012 Lawley et al.
Hanon E.A.,University of Aberdeen |
Hanon E.A.,Rowett Institute of Nutrition and Health |
Hanon E.A.,University of Strasbourg |
Routledge K.,University of Aberdeen |
And 4 more authors.
Journal of Neuroendocrinology | Year: 2010
Recent studies have characterised a retrograde mechanism whereby the pineal hormone melatonin acts in the pars tuberalis (PT) of the pituitary gland to control thyroid hormone action in the hypothalamus, leading to changes in seasonal reproductive function. This involves the release of thyroid-stimulating hormone (TSH) from PT that activates type II deiodinase (DIO2) gene expression in hypothalamic ependymal cells, locally generating biologically active T3, and thus triggering a neuroendocrine cascade. In the present study, we investigated whether a similar regulatory mechanism operates in the European hamster. This species utilises both melatonin signalling and a circannual timer to time the seasonal reproductive cycle. We found that expression of βTSH RNA in the PT was markedly increased under long compared to short photoperiod, whereas TSH receptor expression was localised in the ependymal cells lining the third ventricle, and in the PT, where its expression varied with time and photoperiod. In the ependymal cells at the base of the third ventricle, DIO2 and type III deiodinase (DIO3) expression was reciprocally regulated, with DIO2 activated under long and repressed under short photoperiod, and the reverse case for DIO3. These data are consistent with recent observations in sheep, and suggest that the PT TSH third ventricle-ependymal cell relay plays a conserved role in initiating the photoperiodic response in both long- and short-day breeding mammals. © 2009 The Authors. Journal Compilation © 2009 Blackwell Publishing Ltd.
Louis P.,University of Aberdeen |
Young P.,University of Aberdeen |
Holtrop G.,Rowett Institute of Nutrition and Health |
Flint H.J.,University of Aberdeen
Environmental Microbiology | Year: 2010
Butyrate-producing bacteria play an important role in the human colon, supplying energy to the gut epithelium and regulating host cell responses. In order to explore the diversity and culturability of this functional group, we designed degenerate primers to amplify butyryl-CoA:acetate CoA-transferase sequences from faecal samples provided by 10 healthy volunteers. Eighty-eight per cent of amplified sequences showed > 98% DNA sequence identity to CoA-transferases from cultured butyrate-producing bacteria, and these fell into 12 operational taxonomic units (OTUs). The four most prevalent OTUs corresponded to Eubacterium rectale, Roseburia faecis, Eubacterium hallii and an unnamed cultured species SS2/1. The remaining 12% of sequences, however, belonged to 20 OTUs that are assumed to come from uncultured butyrate-producing strains. Samples taken after ingestion of inulin showed significant (P = 0.019) increases in Faecalibacterium prausnitzii. Because several of the dominant butyrate producers differ in their DNA % G+C content, analysis of thermal melt curves obtained for PCR amplicons of the butyryl-CoA:acetate CoA-transferase gene provides a convenient and rapid qualitative assessment of the major butyrate producing groups present in a given sample. This type of analysis therefore provides an excellent source of information on functionally important groups within the colonic microbial community. © 2009 Society for Applied Microbiology and Blackwell Publishing Ltd.
Johnstone A.M.,University of Aberdeen |
Lobley G.E.,University of Aberdeen |
Horgan G.W.,Rowett Institute of Nutrition and Health |
Bremner D.M.,University of Aberdeen |
And 3 more authors.
British Journal of Nutrition | Year: 2011
There are concerns that weight-loss (WL) diets based on very low carbohydrate (LC) intake have a negative impact on antioxidant status and biomarkers of cardiovascular and metabolic health. Obese men (n 16) participated in a randomised, cross-over design diet trial, with food provided daily, at approximately 8•3 MJ/d (approximately 70 % of energy maintenance requirements). They were provided with two high-protein diets (30 % of energy), each for a 4-week period, involving a LC (4 % carbohydrate) and a moderate carbohydrate (MC, 35 % carbohydrate) content. Body weight was measured daily, and weekly blood samples were collected. On average, subjects lost 6•75 and 4•32 kg of weight on the LC and MC diets, respectively (P < 0•001, sed 0•350). Although the LC and MC diets were associated with a small reduction in plasma concentrations of retinol, vitamin E (Î±- tocopherol) and β-cryptoxanthin (P < 0•005), these were still above the values indicative of deficiency. Interestingly, plasma vitamin C concentrations increased on consumption of the LC diet (P < 0•05). Plasma markers of insulin resistance (P < 0•001), lipaemia and inflammation (P < 0•05, TNF-α and IL-10) improved similarly on both diets. There was no change in other cardiovascular markers with WL. The present data suggest that a LC WL diet does not impair plasma indices of cardiometabolic health, at least within 4 weeks, in otherwise healthy obese subjects. In general, improvements in metabolic health associated with WL were similar between the LC and MC diets. Antioxidant supplements may be warranted if LC WL diets are consumed for a prolonged period. © 2011 The Authors.
Stubbs R.J.,Rowett Institute of Nutrition and Health |
Stubbs R.J.,University of Derby |
O'Reilly L.M.,Rowett Institute of Nutrition and Health |
Whybrow S.,University of Aberdeen |
And 5 more authors.
British Journal of Nutrition | Year: 2014
To date, no study has directly and simultaneously measured the discrepancy between what people actually eat and what they report eating under observation in the context of energy balance (EB). The present study aimed to objectively measure the 'extent' and 'nature' of misreporting of dietary intakes under conditions in which EB and feeding behaviour were continuously monitored. For this purpose, a total of fifty-nine adults were recruited for 12 d, involving two 3 d overt phases and two 3 d covert phases of food intake measurement in a randomised cross-over design. Subjects had ad libitum access to a variety of familiar foods. Food intake was covertly measured using a feeding behaviour suite to establish actual energy and nutrient intakes. During the overt phases, subjects were instructed to self-report food intake using widely accepted methods. Misreporting comprised two separate and synchronous phenomena. Subjects decreased energy intake (EI) when asked to record their food intake (observation effect). The effect was significant in women ( - 8 %, P< 0·001) but not in men ( - 3 %, P< 0·277). The reported EI was 5 to 21 % lower (reporting effect) than the actual intake, depending on the reporting method used. Semi-quantitative techniques gave larger discrepancies. These discrepancies were identical in men and women and non-macronutrient specific. The 'observation' and 'reporting' effects combined to constitute total misreporting, which ranged from 10 to 25 %, depending on the intake measurement assessed. When studied in a laboratory environment and EB was closely monitored, subjects under-reported their food intake and decreased the actual intake when they were aware that their intake was being monitored. © The Authors 2014.
Haggarty P.,University of Aberdeen |
Campbell D.M.,University of Aberdeen |
Knox S.,University of Glasgow |
Horgan G.W.,Rowett Institute of Nutrition and Health |
And 4 more authors.
British Journal of Nutrition | Year: 2013
The aims of the present study were to determine compliance with current advice on vitamin D and to assess the influence of season, dietary intake, supplement use and deprivation on vitamin D status in pregnant mothers and newborns in the north of Scotland where sunlight exposure is low. Pregnant women (n 1205) and their singleton newborns were studied in the Aberdeen Maternity Hospital (latitude 57N) between 2000 and 2006. Plasma 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3 were measured at 19 weeks of gestation in mothers and at delivery in newborns. During pregnancy, 21·0 (95 % CI 18·5, 23·5) % of women took vitamin D supplements. The median intake was 5 μg/d and only 0.6 (95 % CI 0.1, 1·0) % took the recommended 10 μg/d. Supplement use, adjusted for season, dietary intake and deprivation, significantly increased maternal 25-hydroxyvitamin D (25(OH)D) by 10.5 (95 % CI 5·7, 15·2) nmol/l (P< 0.001); however, there was no significant effect on cord 25(OH)D (1·4 (95 % CI - 1·8, 4·5) nmol/l). The biggest influence on both maternal and cord 25(OH)D was season of birth (P< 0.001). Compared with the least deprived women (top three deciles), the most deprived pregnancies (bottom three deciles) were characterised by a significantly lower seasonally adjusted 25(OH)D ( - 11·6 (95 % CI - 7·5, - 15·7) nmol/l in the mother and - 5·8 (95 % CI - 2·3, - 9·4) nmol/l in the cord), and a lower level of supplement use (10 (95 % CI 4, 17) v. 23 (95 % CI 20, 26) %). More should be done to promote vitamin D supplement use in pregnancy but the critical importance of endogenous vitamin D synthesis, and known adaptations of fat metabolism specific to pregnancy, suggest that safe sun advice may be a useful additional strategy, even at high latitude. Copyright © The Authors 2012.
Baines D.L.,St George's, University of London |
Albert A.P.,St George's, University of London |
Hazeli M.J.,St Helier Hospital |
Gambling L.,Rowett Institute of Nutrition and Health |
And 2 more authors.
Pflugers Archiv European Journal of Physiology | Year: 2010
Bacterial lipopolysaccharides (LPS) are potent inducers of proinflammatory signaling pathways via the activation of nuclear factor-kappa B (NF-KB) and mitogenactivated protein kinase (MAPK), causing changes in the processes that control lung fluid homeostasis and contributing to the pathogenesis of lung disease. In human H441 airway epithelial cells, incubation of cells with 15 ng ml-1 LPS caused a significant reduction in amiloride-sensitive / sc from 15±2 to 8±2 uA cm-2 (p=0.01, n=13) and a shift in IC50 amiloride of currents from 6.8 × 10 -7 to 6.4×10-6 M. This effect was associated with a decrease in the activity of 5 pS, highly Na+ selective, amiloride-sensitive <1 u.M. channels (HSC) and an increase in the activity of ∼18 pS, nonselective, amiloride-sensitive >10 uM cation channels (NSC) in the apical membrane. LPS decreased aENaC mRNA and protein abundance, inferring that LPS inhibited aENaC gene expression. This correlated with the decrease in HSC activity, indicating that these channels, but not NSCs, were comprised of at least aENaC protein. LPS increased NF- KB DNA binding activity and phosphorylation of extracellular signal-related kinase (ERK) 1/2, but decreased phosphorylation of ERKS in H.441 cells. Pretreatment of monolayers with PD98059 (20 uM) inhibited ERK1/2 phosphorylation, promoted phosphorylation of ERK5, increased aENaC protein abundance, and reversed the effect of LPS on I80 and the shift in amiloride sensitivity. Inhibitors of NF-KB activation were without effect. Taken together, our data indicate that LPS acts via ERK signaling pathways to decrease ccENaC transcription, reducing HSC/ ENaC channel abundance, activity, and transepithelial Na+ transport in H441 airway epithelial cells.
Reuter M.,University of Edinburgh |
Reuter M.,Erasmus Medical Center |
Hayward N.J.,University of Aberdeen |
Hayward N.J.,Rowett Institute of Nutrition and Health |
And 4 more authors.
Journal of the Royal Society Interface | Year: 2014
Mechanogated channels are fundamental components of bacterial cells that enable retention of physical integrity during extreme increases in cell turgor. Optical tweezers combined with microfluidics have been used to study the fate of individual Escherichia coli cells lacking such channels when subjected to a bursting stress caused by increased turgor. Fluorescence-activated cell sorting and electron microscopy complement these studies. These analyses show that lysis occurs with a high probability, but the precise path differs between individual cells. By monitoring the loss of cytoplasmic green fluorescent protein, we have determined that some cells release this protein but remain phase dark (granular) consistent with the retention of the majority of large proteins. By contrast, most cells suffer cataclysmic wall failure leading to loss of granularity but with the retention of DNA and overall cell shape (protein-depleted ghosts). The time span of these events induced by hypo-osmotic shock varies but is of the order of milliseconds. The data are interpreted in terms of the timing of mechanosensitive channel gating relative to osmotically induced water influx. © 2013 The Authors. Published by the Royal Society.
Ostertag L.M.,University of Aberdeen |
O'Kennedy N.,Provexis plc |
Horgan G.W.,Rowett Institute of Nutrition and Health |
Kroon P.A.,UK Institute of Food Research |
And 2 more authors.
Molecular Nutrition and Food Research | Year: 2011
Scope: Bioactive polyphenols from fruits, vegetables, and beverages have anti-platelet effects and may thus affect the development of cardiovascular disease. We screened the effects of 26 low molecular weight phenolic compounds on two in vitro measures of human platelet function. Methods and results: After platelets had been incubated with one of 26 low molecular weight phenolic compounds in vitro, collagen-induced human platelet aggregation and in vitro TRAP-induced P-selectin expression (as marker of platelet activation) were assessed. Incubation of platelet-rich plasma from healthy volunteers with 100μmol/L hippuric acid, pyrogallol, catechol, or resorcinol significantly inhibited collagen-induced platelet aggregation (all p<0.05; n≥15). Incubation of whole blood with concentrations of 100μmol/L salicylic acid, p-coumaric acid, caffeic acid, ferulic acid, 4-hydroxyphenylpropionyl glycine, 5-methoxysalicylic acid, and catechol significantly inhibited TRAP-induced surface P-selectin expression (all p<0.05; n=10). Incubation with lower concentrations of phenolics affected neither platelet aggregation nor activation. Conclusion: As concentrations of 100μmol/L are unlikely to be reached in the circulation, it is doubtful whether consumption of dietary phenolics in nutritionally attainable amounts plays a major role in inhibition of platelet activation and aggregation in humans. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.