Vitamin D deficiency (˂25nmol/L) and insufficiency (˂50nmol/L) has become an increasingly popular topic. Current research focusses upon the potential ergogenic effects of vitamin D (vitD) in sporting performance; however, the relationship between vitD (dietary intake and nutritional status) and bone health within a University athlete cohort remains under-investigated. Therefore, the aims of this Thesis were to (1) examine vitD status longitudinally across the University competitive seasons and; (2) examine the implications that vitD deficiency/ insufficiency may have upon physical performance parameters or bone health.
In the first study, fifty-seven competitive University level- athletes from varied sports were observed from autumn to spring. Radial bone mineral density (BMD) and physical performance parameters were investigated; for the analysis of vitD and parathyroid hormone, blood samples were collected. Within the cohort 7% presented with deficiency during the autumn; increasing to 44% during spring. However, this did not have a significant effect upon physical performance and bone health despite an average status of 31.5±16.4 nmol/L in spring.
In the second study, 34 University athletes and sixteen sedentary students were recruited and followed from spring to summer. Whole body, hip and tibial scans were conducted to determine BMD and bone mineral content (BMC). Physical performance parameters including jump height, aerobic fitness, muscular strength and blood biochemistry were also collected. During the summer term, 26% of the cohort were vitD insufficient. Moreover, an insufficient vitD status was associated with a lowered jump height (p=0.015) but not aerobic fitness (p=0.07). There was also a significant positive relationship between vitD status, femoral neck BMC (r=0.685; p˂0.02) and BMD (r=0.679; p˂0.02). Our results show that BMD was higher in weight bearing athletes. The final study found that racket sport athletes had a significantly superior bone profile in their dominant arm when contrasted to controls.
Overall, these findings suggest that an insufficient vitD status was associated with lower indices of muscular power and aerobic fitness in University students. Therefore, being vitD replete may not only play an important role in musculoskeletal health but could also be a key determining factor in athletic performance.
Base excision repair (BER) is a pathway that repairs DNA damage inflicted by oxidative stress, certain alkylating agents, and spontaneous hydrolysis. Assays to measure the BER pathway are usually limited by being low-throughput, time consuming, and unable to measure each step of the pathway in addition to complete repair. The aim of the present work was to develop an assay format to overcome these limitations, and use this to develop a mathematical model to examine differences between cell types on flux through the pathway. A novel assay format was developed and optimised to measure uracil DNA glycosylase, AP endonuclease, DNA polymerase β, DNA ligase, AP site repair and complete base repair. Data was generated for each enzyme activity in HepG2, Caco-2, and peripheral blood mononuclear cells (PBMCs), and the effects on the pathway were predicted using a mathematical model. In addition, the assay was used to examine variability in enzyme activity between the two cell lines, correlations between enzyme activities in primary human cells, and the effects of caloric restriction on BER in a human weight loss intervention trial. The model revealed marked differences in the response to aberrant uracil between the two immortalised cell lines and the PBMCs, with PBMC nuclear extract in general excising the base more slowly and causing a smaller and slower accumulation of harmful intermediates, such as abasic sites and single strand breaks, compared to the immortalised cell lines. The model underestimated complete repair when compared to the biological data for all cell types, potentially due to cooperativity between BER enzymes not captured when repair steps were measured individually under experimental conditions. There were also significant correlations found between enzyme activities in PBMC extracts from different individuals, and a significant predictive effect of weight loss method on polymerase β activity in the caloric restriction trial. In conclusion, the research described here uncovered novel information regarding the effects of weight loss on DNA repair, and correlations between BER enzyme activities in healthy volunteers. This is also the first work to compare BER profiles of different cell types using biological data and mathematical modelling.
Alhumaydhi Fahad A., de O. Lopes Debora, Bordin Diana L., Aljohani Abdullah S. M., Lloyd Cameron B., McNicholas Michael D., Milano Larissa, Charlier Clara F., Plant Kathryn E., Elliott Ruan M., Meira Lisiane B., Villela Izabel, Henriques João Antonio P. (2020)Alkyladenine DNA glycosylase deficiency uncouples alkylation-induced strand break generation from PARP-1 activation and glycolysis inhibition, In: Scientific Reports10(1)
Nature Publishing Group
DNA alkylation damage is repaired by base excision repair (BER) initiated by alkyladenine DNA glycosylase (AAG). Despite its role in DNA repair, AAG-initiated BER promotes cytotoxicity in a process dependent on poly (ADP-ribose) polymerase-1 (PARP-1); a NAD+-consuming enzyme activated by strand break intermediates of the AAG-initiated repair process. Importantly, PARP-1 activation has been previously linked to impaired glycolysis and mitochondrial dysfunction. However, whether alkylation affects cellular metabolism in the absence of AAG-mediated BER initiation is unclear. To address this question, we temporally profiled repair and metabolism in wild-type and Aag−I− cells treated with the alkylating agent methyl methanesulfonate (MMS). We show that, although Aag−I− cells display similar levels of alkylation-induced DNA breaks as wild type, PARP-1 activation is undetectable in AAG-deficient cells. Accordingly, Aag−I− cells are protected from MMS-induced NAD+ depletion and glycolysis inhibition. MMS-induced mitochondrial dysfunction, however, is AAG-independent. Furthermore, treatment with FK866, a selective inhibitor of the NAD+ salvage pathway enzyme nicotinamide phosphoribosyltransferase (NAMPT), synergizes with MMS to induce cytotoxicity and Aag−I− cells are resistant to this combination FK866 and MMS treatment. Thus, AAG plays an important role in the metabolic response to alkylation that could be exploited in the treatment of conditions associated with NAD+ dysregulation.
Tripkovic Laura, Wilson LR, Hart Kathryn, Johnsen Sigurd, de Lusignan Simon, Smith CP, Bucca G, Penson S, Chope G, Elliott Ruan, Hypponen E, Berry J L, Lanham-New Susan (2017)Daily supplementation with 15 mg vitamin D2 compared with vitamin D3 to increase wintertime 25-hydroxyvitamin D status in healthy South Asian and white European women: a 12-wk randomized, placebo-controlled food-fortification trial, In: American Journal of Clinical Nutrition106(2)pp. 481-490
American Society for Nutrition
Background: There are conflicting views in the literature as to whether vitamin D2 and vitamin D3 are equally effective in increasing and maintaining serum concentrations of 25-hydroxyvitamin D [25(OH)D], particularly at lower doses of vitamin D. Objective: We aimed to investigate whether vitamin D2 or vitamin D3 fortified in juice or food, at a relatively low dose of 15 μg/d, was effective in increasing serum total 25(OH)D and to compare their respective efficacy in South Asian and white European women over the winter months within the setting of a large randomized controlled trial. Design: A randomized, double-blind, placebo-controlled food-fortification trial was conducted in healthy South Asian and white European women aged 20–64 y (n = 335; Surrey, United Kingdom) who consumed placebo, juice supplemented with 15 μg vitamin D2, biscuit supplemented with 15 μg vitamin D2, juice supplemented with 15 μg vitamin D3, or biscuit supplemented with 15 μg vitamin D3 daily for 12 wk. Serum 25(OH)D was measured by liquid chromatography–tandem mass spectrometry at baseline and at weeks 6 and 12 of the study. Results: Postintervention in the 2 ethnic groups combined, both the vitamin D3 biscuit and the vitamin D3 juice groups showed a significantly greater absolute incremental change (Δ) in total 25(OH)D when compared with the vitamin D2 biscuit group [Δ (95% CI): 15.3 nmol/L (7.4, 23.3 nmol/L) (P < 0.0003) and 16.0 nmol/L (8.0, 23.9 nmol/L) ( P < 0.0001)], the vitamin D2 juice group [Δ (95% CI): 16.3 nmol/L (8.4, 24.2 nmol/L) (P < 0.0001) and 16.9 nmol/L (9.0, 24.8 nmol/L) (P < 0.0001)], and the placebo group [Δ (95% CI): 42.3 nmol/L (34.4, 50.2 nmol/L) (P < 0.0001) and 42.9 nmol/L (35.0, 50.8 nmol/L) (P < 0.0002)]. Conclusions: With the use of a daily dose of vitamin D relevant to public health recommendations (15 μg) and in vehicles relevant to food-fortification strategies, vitamin D3 was more effective than vitamin D2 in increasing serum 25(OH)D in the wintertime. Vitamin D3 may therefore be a preferential form to optimize vitamin D status within the general population. This trial was registered at www.controlled-trials.com as ISRCTN23421591.
de Roos B, Duthie SJ, Polley ACJ, Mulholland F, Bouwman FG, Heim C, Rucklidge GJ, Johnson IT, Mariman EC, Daniel H, Elliott RM (2008)Proteomic methodological recommendations for studies involving human plasma, platelets, and peripheral blood mononuclear cells, In: JOURNAL OF PROTEOME RESEARCH7(6)pp. 2280-2290
AMER CHEMICAL SOC
Elliott RM, de Roos B, Duthie SJ, Bouwman FG, Rubio-Aliaga I, Crosley LK, Mayer C, Polley AC, Heim C, Coort SL, Evelo CT, Mulholland F, Daniel H, Mariman EC, Johnson IT (2014)Transcriptome analysis of peripheral blood mononuclear cells in human subjects following a 36 h fast provides evidence of effects on genes regulating inflammation, apoptosis and energy metabolism, In: GENES AND NUTRITION9(6)ARTN 4
There is growing interest in the potential health benefits of diets that involve regular periods of fasting. While animal studies have provided compelling evidence that feeding patterns such as alternate-day fasting can increase longevity and reduce incidence of many chronic diseases, the evidence from human studies is much more limited and equivocal. Additionally, although several candidate processes have been proposed to contribute to the health benefits observed in animals, the precise molecular mechanisms responsible remain to be elucidated. The study described here examined the effects of an extended fast on gene transcript profiles in peripheral blood mononuclear cells from ten apparently healthy subjects, comparing transcript profiles after an overnight fast, sampled on four occasions at weekly intervals, with those observed on a single occasion after a further 24 h of fasting. Analysis of the overnight fasted data revealed marked inter-individual differences, some of which were associated with parameters such as gender and subject body mass. For example, a striking positive association between body mass index and the expression of genes regulated by type 1 interferon was observed. Relatively subtle changes were observed following the extended fast. Nonetheless, the pattern of changes was consistent with stimulation of fatty acid oxidation, alterations in cell cycling and apoptosis and decreased expression of key pro-inflammatory genes. Stimulation of fatty acid oxidation is an expected response, most likely in all tissues, to fasting. The other processes highlighted provide indications of potential mechanisms that could contribute to the putative beneficial effects of intermittent fasting in humans.
Wilson L, Hart K, Elliott R, Smith CP, Bucca G, Penson S, Chope G, Hypponen E, Berry J, Lanham-New S, Tripkovic L (2015)The D2-D3 Study: comparing the efficacy of 15 mu g/d vitamin D2 vs. D3 in raising vitamin D status in both South Asian and Caucasian women, and the ethical implications of placebo treatment, In: PROCEEDINGS OF THE NUTRITION SOCIETY74(OCE1)pp. E116-E116
CAMBRIDGE UNIV PRESS
OBEN J, Elliott Ruan, MORGAN L, FLETCHER J, MARKS V (1992)THE ROLE OF GUT HORMONES IN THE ADIPOSE-TISSUE METABOLISM OF LEAN AND GENETICALLY-OBESE (OB OB) MICE, In: AILHAUD G, GUYGRAND B, LAFONTAN M, RICQUIER D, (eds.), OBESITY IN EUROPE 91pp. 269-272
The anti-cancer activity of selenium is dose-dependent and species-specific but the mechanism is unclear. Se-methylselenocysteine (MSC), found in selenium-enriched alliums, is one of the most potent forms. We exposed two human prostate cell lines (LNCaP clone FGC and PNT1A) to nutritionally relevant doses of MSC and selenite, ranging from deficient to the equivalent of selenium supplementation in humans. The cells were adapted for one month to attain steady-state selenium status. Two microarray platforms, an in-house printed microarray (14,000 genes) and the Affymetrix U133A array (22,000 genes) were used to probe the molecular effects of selenium dose and form and several selenium-responsive genes were identified, many of which have been ascribed to cancer cell growth and progression. In response to MSC supplementation, the expression of 23 genes changed significantly, including several collagen genes. Quantitative RT-PCR assays were designed and optimized for four of the collagen genes to validate array data. Significant decreases in expression of collagen type I alpha 1 (COL1A1), COL1A2 and COL7A1 genes were observed in cells adapted to MSC supplementation compared to the control and selenite exposed cells. There were significant increases in genes encoding other types of collagen, including significant increases in COL6A1 and COL4A5 in response to MSC dose. Functional changes in collagen type I protein expression in response to MSC were confirmed by ELISA. This study reveals for the first time that MSC can alter the expression of several types of collagen and thus potentially modulate the extracellular matrix and stroma, which may at least partially explain the anti-cancer activity of MSC.
The wealth of freely available genetic information derived from genome mapping projects and the development of functional genomic and other powerful molecular biological tools have lead to profound changes in the scope of life science research and the way it is performed. As in many other disciplines, scientists in the fields of food science and nutrition are now beginning to fully realise the enormous potential these new resources and are seeking to integrate them into their research. However, there are still a number of issues specific to nutrition research that need to be addressed to ensure that this opportunity is exploited to the full. Copyright © 2005 by New Century Health Publishers, LLC.
Kolm Paul, Mariathas Mark, Curzen Nick, Mahmoudi Michael, Shah Nikunj, Meira Lisiane B., Elliott Ruan M., Hoole Stephen P., West Nick E., Kuku Kayode O., Brown Adam J., Bennett Martin R., Garcia-Garcia Hector M., Dan Kazuhiro (2019)DNA damage and repair in patients with coronary artery disease: Correlation with plaque morphology using optical coherence tomography (DECODE study), In: Cardiovascular Revascularization Medicine20(9)pp. 812-818
The aim of this study was to examine DNA ligase activity and expression of DNA damage response pathway (DDR) genes in patients with stable angina (SA) and non-ST elevation myocardial infarction (NSTEMI) and determine whether they correlate with plaque morphology.
Patients with coronary artery disease (CAD) have evidence of deoxyribonucleic acid (DNA) damage in peripheral blood mononuclear cells (PBMCs). It is unclear whether this represents excess damage or defective DNA repair activity.
DNA ligase activity and the expression of 22 DDR genes were measured in PBMCs of patients (both SA (n = 47) and NSTEMI (n = 42)) and in age and gender-matched controls (n = 35). Target lesion anatomical assessment was undertaken with frequency domain optical coherent tomography.
DNA ligase activity was different across the three groups of patients (control = 119 ± 53, NSTEMI = 115.6 ± 85.1, SA = 81 ± 55.7 units/g of nuclear protein; ANOVA p = 0.023). Pair wise comparison demonstrated that this significance is due to differences between the control and SA patients (p = 0.046). Genes involved in double strand break repair and nucleotide excision repair pathways were differentially expressed in patients with SA and NSTEMI. In SA patients, fibrocalcific plaques were strongly associated with GTSE1, DDB1, MLH3 and ERCC1 expression. By contrast, in NSTEMI patients the strongest association was observed between fibrous plaques and ATM and XPA expression.
PBMCs from patients with CAD exhibit differences in DNA ligase activity and expression of DDR genes. Expression levels of certain DDR genes are strongly associated with plaque morphology and may play a role in plaque development and progression.
This review examines the extent to which transcriptomic methods have lived up to their promise in the context of nutrition research, placing particular emphasis on examples from micronutrient research. A case is made that the high quality platform technologies now available, together with established standards and systems for data storage and exchange and powerful new methods of data analysis, mean that microarrays have reached a level of technical maturity at which they can be exploited to their full potential. In the context of nutrition and micronutrient research, transcriptomic methods have already been widely applied, albeit primarily in studies using cell lines and animal models. Using this type of approach, a multitude of genes regulated at the mRNA level by dietary components has been identified and this, in turn, has provided new insights into the biological processes affected by nutritional parameters. Evidence from the very limited number of published transcriptomics-based nutritional studies performed in human volunteers suggests that, with appropriate study design, it is feasible to apply transcriptomic methods successfully in dietary intervention trials. On the other hand, gene expression-based biomarker development still poses a major challenge. Here the use of expression profile 'signatures', rather than single genes, may provide a solution. Approaches designed to identify such 'signatures' are being developed and tested widely, primarily in the context of medical research. The applicability and power of such approaches should also be evaluated in the context of nutrition.
Rubio-Aliaga I, de Roos B, Duthie SJ, Crosley LK, Mayer C, Horgan G, Colquhoun IJ, Le Gall G, Huber F, Kremer W, Rychlik M, Wopereis S, van Ommen B, Schmidt G, Mulholland F, Heim C, Bouwman FG, Mariman EC, Johnson IT, Polley AC, Elliott RM, Daniel H (2011)Metabolomics of prolonged fasting in humans reveals new catabolic markers, In: METABOLOMICS7(3)pp. 375-387
Crosley LK, Duthie SJ, Mulholland F, Polley AC, Bouwman FG, Heim C, Horgan G, Johnson IT, Mariman EC, Elliott RM, Daniel H, de Roos B (2009)Variation in protein levels obtained from human blood cells and biofluids for platelet, peripheral blood mononuclear cell, plasma, urine and saliva proteomics, In: GENES AND NUTRITION4(2)pp. 95-102
We are exposed to a complex mixture of food compounds in the womb and eat a composite mixture of foods throughout life. Our taste changes as we grow and mature, and we become influenced by external factors such as holidays and advertising by the food industry. Intricate biochemical processes extract energy and other useful components, enabling us to grow and live and keep our bodies and minds functioning effectively. There are, however, many food compounds that have biological effects within our bodies, and diet and disease are intimately associated. To address the fractured nature of nutrigenomic research, leading centres in nutritional research from across Europe have put together a Network of Excellence, the European Nutrigenomics Organisation (NuGO): linking genomics, nutrition and health research. Led by Dr Ben van Ommen of the Dutch Centre for Human Nutrigenomics, NuGO has been awarded €17.3 million over a period of 6 years. The project has been over a year, in preparation and currently has 22 partners from 10 EU member states. © 2004 British Nutrition Foundation.
DNA repair capacity varies greatly between individuals, and evidence has begun to link this variation to cancer risk, obesity and related chronic diseases. There is also emerging evidence that dietary components can affect DNA repair, but research to date has been restricted by methods for measuring DNA repair. This study made use of newly developed microplate-based assays for the direct determination of DNA repair enzyme activities. Lipid loading of the HepG2 human hepatocellular carcinoma cell line was employed as a model to test the hypothesis that hepatic steatosis affects DNA repair activity via induction of oxidative stress.
van Ommen B, El-Sohemy A, Hesketh J, Kaput J, Fenech M, Evelo C, McArdle H, Bouwman J, Lietz G, Mathers J, Fairweather-Tait S, van Kranen H, Elliott R, Wopereis S, Ferguson LR, Meplan C, Perozzi G, Allen L, Revero D, The Micronutrient Genomics Project Working Group (2010)The micronutrient genomics project: creating a community driven knowledge base for micronutrient research, In: Genes Nutr5(4)pp. 285-296 Smith CP, Bucca G, Penson S, Chope G, Hypponen E, Berry J, Lanham-New S, Tripkovic L, Wilson LR, Hart K, Elliott R (2014)DAILY SUPPLEMENTATION WITH VITAMIN D3 IS COMPREHENSIVELY MORE EFFECTIVE THAN VITAMIN D2 IN RAISING 25OHD STATUS AND CONCOMITANTLY REDUCING PARATHYROID HORMONE LEVELS: IMPLICATIONS FOR BONE HEALTH, In: OSTEOPOROSIS INTERNATIONAL25pp. S665-S665
Iron homeostasis in the human body is maintained primarily through regulation of iron absorption in the duodenum. The liver peptide hepcidin plays a central role in this regulation. Additionally, expression and functional control of certain components of the cellular iron transport machinery can be influenced directly by the iron status of enterocytes. The significance of this modulation, relative to the effects of hepcidin, and the comparative effects of iron obtained directly from the diet and/or via the bloodstream are not clear. The studies described here were performed using Caco-2 cell monolayers as a model of intestinal epithelium, to compare the effects of iron supplied in physiologically relevant forms to either the apical or basolateral surfaces of the cells. Both sources of iron provoked increased cellular ferritin content, indicating iron uptake from both sides of the cells. Supply of basolateral transferrin-bound iron did not affect subsequent iron transport across the apical surface, but reduced iron transport across the basolateral membrane. In contrast, the apical iron supply led to subsequent reduction in iron transport across the apical cell membrane without altering iron export across the basolateral membrane. The apical and basolateral iron supplies also elicited distinct effects on the expression and subcellular distribution of iron transporters. These data suggest that, in addition to the effects of cellular iron status on the expression of iron transporter genes, different modes and direction of iron supply to enterocytes can elicit distinct functional effects on iron transport.
Background: Allergic rhinitis is one of the most prevalent manifestation of allergy, affecting over 15% of the population worldwide. Recent published clinical studies have shown that specific probiotics can improveallergic rhinitis clinical symptoms. Findings: In this study, thirty one adult volunteers suffering from allergic rhinitis were enrolled in a crossover study evaluating the efficacy of the consumption of a product containing either L. paracasei-fermented milk or the placebo. Transcriptomic analysis was performed on unstimulated PBMC after each treatment period and analysis was adjusted for the crossover design. No differences were observed between PBMCs from probiotic treated allergen challenged allergic patients and PBMCs from placebo treated allergen challenged allergic patients. Conclusion: This study shows that, in the blood compartment, PBMCs mRNA levels are too stable to mirror the changes of symptoms and alteration of cytokine expressions observed after a treatment with L. paracasei.
Kaput J, Ordovas JM, Ferguson L, van Ommen B, Rodriguez RL, Allen L, Ames BN, Dawson K, German B, Krauss R, Malyj W, Archer MC, Barnes S, Bartholomew A, Birk R, van Bladeren P, Bradford KJ, Brown KH, Clarke S, Caetano R, Castle D, Chadwick R, Clement K, Cooney CA, Corella D, da Cruz IBM, Daniel H, Duster T, Felton J, Ebbesson SOE, Elliott R, Fairweather-Tait S, Fenech M, Finley JW, Fogg-Johnson N, Gill-Garrison R, Gibney MJ, Gillies PJ, Hwang JK, Gustafsson JA, Hartmann JL, He L, Jais JP, Jang YS, Kibbe WA, Joost H, Junien C, Kanter M, Koletzko B, Korf BR, Kornman K, Krempin DW, Langin D, Lauren DR, Mathers J, Lee JH, Leveille GA, Lin SJ, Mayne M, McNabb W, Milner JA, Morgan P, Muller M, Nikolsky Y, Perez-Jimenez F, van der Ouderaa F, Park T, Pensel N, Poutanen K, Roberts M, Saris WHM, Southon S, Schuster G, Shelling AN, Simopoulos AP, Tai ES, Towne B, Trayhurn P, Uauy R, Visek WJ, Warden C, Wolff GL, Weiss R, Wiencke J, Winkler J, Xi ZW, Zucker JD (2005)The case for strategic international alliances to harness nutritional genomics for public and personal health, In: BRITISH JOURNAL OF NUTRITION94(5)pp. 623-632
CAMBRIDGE UNIV PRESS
DNA repair is essential for the maintenance of genomic integrity, and evidence suggest that interindividual variation in DNA repair efficiency maycontribute to disease risk. However, robust assays suitable for quantitative determination of DNA repair capacity in large cohort and clinical trials are needed to evaluate these apparent associations fully. We describe here a set of microplate-based oligonucleotide assays for high-throughput, non-radioactiveand quantitative determination of repair enzyme activity at individual steps and over multiple steps of the DNA base excision repair pathway. The assays are highly sensitive: using HepG2 nuclear extract, enzyme activities were quantifiable at concentrationsof 0.0002 to 0.181 g per reaction, depending on the enzyme being measured. Assay coefficients of variation are comparable with other microplate-based assays. The assay format requires no specialist equipment and has the potential to be extended for analysis of a wide range of DNA repair enzyme activities. As such, these assays hold considerable promise for gaining new mechanistic insights into how DNA repair is related to individual genetics, disease status or progression and other environmental factors and investigating whether DNA repair activities can be used a biomarker of disease risk.
van Ommen B, Bouwman J, Dragsted LO, Drevon CA, Elliott R, de Groot P, Kaput J, Mathers JC, Mueller M, Pepping F, Saito J, Scalbert A, Radonjic M, Rocca-Serra P, Travis A, Wopereis S, Evelo CT (2010)Challenges of molecular nutrition research 6: the nutritional phenotype database to store, share and evaluate nutritional systems biology studies, In: GENES AND NUTRITION5(3)pp. 189-203
Jackson MJ, Papa S, Bolaños J, Bruckdorfer R, Carlsen H, Elliott RM, Flier J, Griffiths HR, Heales S, Holst B, Lorusso M, Lund E, Øivind Moskaug J, Moser U, Di Paola M, Polidori MC, Signorile A, Stahl W, Viña-Ribes J, Astley SB (2002)Antioxidants, reactive oxygen and nitrogen species, gene induction and mitochondrial function., In: Mol Aspects Med23(1-3)pp. 209-285 Caesar R, Cinti S, Coort SL, Crosley K, Daniel H, Drevon CA, Duthie S, Eijssen L, Elliott RM, van Erk M, Evelo C, Gibney M, Heim C, Horgan GW, Johnson IT, Kelder T, Kleemann R, Kooistra T, van Iersel MP, Mariman EC, Mulholland F, Mayer C, McLoughlin G, Müller M, van Ommen B, Polley AC, Pujos-Guillot E, Rubio-Aliaga I, Roche HM, de Roos B, de Wit N, Sailer M, Tonini G, Williams LM, For the NuGO PPS Team , Boekschoten MV, Baccini M, Bachmaier EM, Biggeri A, Bouwman FG, Brennan L (2008)The NuGO proof of principle study package: a collaborative research effort of the European Nutrigenomics Organisation., In: Genes Nutr3(3-4)pp. 147-151 Mas Claret Eduard, Al Yahyaei Balqees, Chu Shuyu, Elliott Ruan M., Imperato Manuel, Lopez Arnaud, Meira Lisiane B., Howlin Brendan J., Whelligan Daniel K. (2020)An aza-nucleoside, fragment-like inhibitor of the DNA repair enzyme alkyladenine glycosylase (AAG), In: Bioorganic & Medicinal Chemistry28(11)115507
The DNA repair enzyme AAG has been shown in mice to promote tissue necrosis in response to ischaemic reperfusion or treatment with alkylating agents. A chemical probe inhibitor is required for investigations of the biological mechanism causing this phenomenon and as a lead for drugs that are potentially protective against tissue damage from organ failure and transplantation, and alkylative chemotherapy. Herein, we describe the rationale behind the choice of arylmethylpyrrolidines as appropriate aza-nucleoside mimics for an inhibitor followed by their synthesis and the first use of a microplate-based assay for quantification of their inhibition of AAG. We finally report the discovery of an imidazol-4-ylmethylpyrrolidine as a fragment-sized, weak inhibitor of AAG.
Individuals respond differently to nutrients and foods. This is reflected in different levels of benefits and risks at the same intake of a nutrient and, consequently, different 'windows of benefit' in terms of nutrient intake. This has led recently to the concept of 'personalised nutrition'. Genetic factors such as single nucleotide polymorphisms may be one source of this inter-individual variation in benefit-risk response to nutrients. In 2004 a European Union-funded network of excellence in the area of nutrigenomics (European Nutrigenomics Organisation; NuGO) organised a workshop on the role of nutrient-gene interactions in determining benefit-risk of nutrients and diet. The major issues discussed at the workshop are presented in the present paper and highlighted with examples from the presentations. The overall consensus was that although genetics provides a new vision where genetic information could in the future be used to provide knowledge on disease predisposition and nutritional requirements, such a goal is still far off and much more research is required before we can reliably include genetic factors in the risk-benefit assessment of nutrients and diets.
Colorectal cancer (CRC) is the third most common type of cancer and the fourth most common cause of cancer-related death worldwide. The incidence and mortality of CRC are higher in more developed regions than in less developed regions and they are also higher in males than in females from 45.7% to 7% and from 16.1% to 5.5%, respectively. These and other data suggest CRC may be amenable to improve prevention by suitable lifestyle interventions, including dietary modification. Quercetin (QC) is a flavonoid obtained from plants that can reach concentrations in the gastrointestinal tract in the range of 0.16–1.30 µM as determined by LC-MS analysis of faecal water. However, many other compounds are also present in faecal water, including those from other plants (e.g. SFN released from brassicas) and DHCA (3,4-dihydroxyphenylpropionic acid), which is a colonic microflora catabolite of the major dietary phenolic acids, derived from the consumption of fruits, vegetables, coffee, and tea. The investigation was done to assess the cytotoxic effect of individual components in human colon adenocarcinoma (Caco-2) cells and primary human colonic epithelial cells (HCoEpiC). It also investigates whether synergistic interactions or additive interactions occur between mixtures of QC, DHCA, and SFN in terms of potential cytotoxic activity in Caco-2 and HCoEpiC and it compares the effects observed in the cancer cell line with those in HCoEpiC. The study demonstrated that Caco-2 cells or HCoEpiC were treated with various concentrations of QC (0-150 µM), DHCA (0-500 µM) or SFN (0-200 µM) individually and in combination, to determine the half maximal inhibitory concentration (IC50) value using the methylthiazol tetrazolium (MTT) assay. This has resulted in that QC and SFN had both concentration and time-dependent cytotoxic effects on Caco-2 cells (IC50 50 µM, p > 0.001 and 32 µM, p > 0.0001 for QC and 45 µM, p > 0.05 and 20 µM, p > 0.0001 for SFN after 24 and 48 h, respectively). DHCA only showed detectable cytotoxic effect in Caco-2 cells at the highest concentration tested. QC had no detectable cytotoxic effect on HCoEpiC, while SFN showed a very similar cytotoxic effect in HCoEpiC (IC50 19.21 µM, p > 0.0001), DHCA had no cytotoxic effect. However, SFN supplementation increased QC cytotoxicity in Caco-2 and HCoEpiC at low concentrations. Moreover, DHCA appeared to cause an increase in viability or cell number at all SFN concentrations tested in HCoEpiC but not in HCoEpiC. DHCA supplementation had a clear influence on QC-induced cytotoxicity in Caco-2 and but not in HCoEpiC. In conclusion, combinations of the phytochemicals at low concentrations exhibited even greater cytotoxic effects than phytochemicals individually in CRC cells and they do not have an effect on primary. These data suggest the three phytochemicals each exhibit unique and distinct effects in CRC and primary colon cells. It is clear from the present studies that some combinations of phytochemicals can have an additive interaction effect rather than a synergistic interaction in CRC growth cells. In summary, evidence suggests that a combination of phytochemicals is a good candidate for further anticancer studies.
It is estimated that 10,000 lesions arise in the genome of a cell every day. Cells have therefore also evolved ways to protect the integrity of their genomes using direct DNA repair enzymes and multi-step pathways including base excision repair and nucleotide excision repair. Alkylating agents are reactive chemicals that transfer alkyl groups to biological molecules, including DNA. The base excision repair pathway mainly repairs non-bulky lesions produced by alkylation, oxidation or deamination of bases. This pathway is initiated by alkyladenine DNA glycosylase (Aag). Antioxidants neutralise free radicals including reactive oxygen specied (ROS), and have been widely reported to protect against disease. However, some studies have also reported that anti-oxidants may instead make disease progression worse. This thesis aims at evaluating the role of antioxidants in the cellular response to the alkylating agent, methylmethane sulfonate. WT and Aag-deficient mouse embryonic fibroblasts (MEFs) were pre-treated with the antioxidant N-acetylcysteine (NAC) and exposed to MMS. NAC increased MMS-induced cell death in both Aag-deficient and wild-type (WT) MEFs. These were further confirmed with embryonic stem cells (ESc) being also sensitized to MMS-induced cell death by the anti-oxidant 2-mercaptoethanol (2-ME); and with 661W photoreceptor cells being sensitised to MMS-induced cell death by a commercial antioxidant mixture and NAC. MEFs exhibited ROS generation when exposed to MMS, which was abrogated with NAC. The mitochondrial superoxide probe MitoSox proves that the MMS-induced ROS generation did not originate from the mitochondria. The NADPH oxidase inhibitor Diphenyleneiodonium (DPI) abrogated MMS-induced ROS generation and also sensitised cells to MMS in a similar fashion to NAC. Collectively, we conclude that cells generate ROS as a response to MMS treatment, and that this ROS generation is essential for cell survival. We also show by using different glucose concentrations, ATP levels appear to be irrelevant to MMS-induced cell death, and that higher basal NAD levels correlates with higher amount of MMS-induced cell death.