26 results on '"Tom Ashmore"'
Search Results
2. Myc linked to dysregulation of cholesterol transport and storage in nonsmall cell lung cancer
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Zoe Hall, Catherine H. Wilson, Deborah L. Burkhart, Tom Ashmore, Gerard I. Evan, and Julian L. Griffin
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cholesteryl ester ,liquid extraction surface analysis ,mass spectrometry ,lipid metabolism ,adenocarcinoma ,Biochemistry ,QD415-436 - Abstract
Nonsmall cell lung cancer (NSCLC) is a leading cause of cancer-related deaths. While mutations in Kras and overexpression of Myc are commonly found in patients, the role of altered lipid metabolism in lung cancer and its interplay with oncogenic Myc is poorly understood. Here we use a transgenic mouse model of Kras-driven lung adenocarcinoma with reversible activation of Myc combined with surface analysis lipid profiling of lung tumors and transcriptomics to study the effect of Myc activity on cholesterol homeostasis. Our findings reveal that the activation of Myc leads to the accumulation of cholesteryl esters (CEs) stored in lipid droplets. Subsequent Myc deactivation leads to further increases in CEs, in contrast to tumors in which Myc was never activated. Gene expression analysis linked cholesterol transport and storage pathways to Myc activity. Our results suggest that increased Myc activity is associated with increased cholesterol influx, reduced efflux, and accumulation of CE-rich lipid droplets in lung tumors. Targeting cholesterol homeostasis is proposed as a promising avenue to explore for novel treatments of lung cancer, with diagnostic and stratification potential in human NSCLC.
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- 2020
- Full Text
- View/download PDF
3. Metabolomics dataset of PPAR-pan treated rat liver
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Zsuzsanna Ament, James A. West, Elizabeth Stanley, Xuefei Li, Tom Ashmore, Lee D. Roberts, Jayne Wright, Andrew W. Nicholls, and Julian L. Griffin
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Computer applications to medicine. Medical informatics ,R858-859.7 ,Science (General) ,Q1-390 - Abstract
This article contains mass spectrometry (MS) data investigating small molecule changes as an effect of a triple peroxisome proliferator-activated receptor (PPAR-pan) agonist GW625019 in the liver as described in the manuscript (Ament et al., 2016) [1]. Samples were measured using gas chromatography-mass spectrometry (GC–MS) for total fatty acid content, and liquid chromatography-mass spectrometry (LC–MS) to measure intact lipids, carnitines and selected aqueous metabolites and eicosanoids. Data files comprise of Excel (Microsoft, WA, USA) spreadsheets of identified metabolites and their area ratio values for total fatty acids, carnitines, aqueous metabolites, and eicosanoids where the intensity of the analytes were normalised to the intensity of the internal standard. In the case of open profiling intact lipid data, the Excel file contains area ratio values of retention time and mass to charge ratio pairs; again, the area ratio values were calculated by normalising to the intensity of the internal standard. It should be noted that several metabolic changes are potentially indirect (secondary, tertiary and ensuing changes). Keywords: Peroxisome proliferator activated receptors, PPAR, Metabolomics, Lipidomics, Mass spectrometry
- Published
- 2016
- Full Text
- View/download PDF
4. Supplemental Figure Legends from Myc Expression Drives Aberrant Lipid Metabolism in Lung Cancer
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Julian L. Griffin, Gerard I. Evan, Trevor Littlewood, Albert Koulman, Tom Ashmore, Deborah L. Burkhart, Catherine H. Wilson, Zsuzsanna Ament, and Zoe Hall
- Abstract
Figure legends for supplemental Figures S1-S6.
- Published
- 2023
5. Figure S3 from Myc Expression Drives Aberrant Lipid Metabolism in Lung Cancer
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Julian L. Griffin, Gerard I. Evan, Trevor Littlewood, Albert Koulman, Tom Ashmore, Deborah L. Burkhart, Catherine H. Wilson, Zsuzsanna Ament, and Zoe Hall
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Liquid extraction surface analysis mass spectrometry differentiates normal from tumour tissue.
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- 2023
6. Data from Myc Expression Drives Aberrant Lipid Metabolism in Lung Cancer
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Julian L. Griffin, Gerard I. Evan, Trevor Littlewood, Albert Koulman, Tom Ashmore, Deborah L. Burkhart, Catherine H. Wilson, Zsuzsanna Ament, and Zoe Hall
- Abstract
MYC-mediated pathogenesis in lung cancer continues to attract interest for new therapeutic strategies. In this study, we describe a transgenic mouse model of KRAS-driven lung adenocarcinoma that affords reversible activation of MYC, used here as a tool for lipidomic profiling of MYC-dependent lung tumors formed in this model. Advanced mass spectrometric imaging and surface analysis techniques were used to characterize the spatial and temporal changes in lipid composition in lung tissue. We found that normal lung tissue was characterized predominantly by saturated phosphatidylcholines and phosphatidylglycerols, which are major lipid components of pulmonary surfactant. In contrast, tumor tissues displayed an increase in phosphatidylinositols and arachidonate-containing phospholipids that can serve as signaling precursors. Deactivating MYC resulted in a rapid and dramatic decrease in arachidonic acid and its eicosanoid metabolites. In tumors with high levels of MYC, we found an increase in cytosolic phospholipase A2 (cPLA2) activity with a preferential release of membrane-bound arachidonic acid, stimulating the lipoxygenase (LOX) and COX pathways also amplified by MYC at the level of gene expression. Deactivating MYC lowered cPLA2 activity along with COX2 and 5-LOX mRNA levels. Notably, inhibiting the COX/5-LOX pathways in vivo reduced tumor burden in a manner associated with reduced cell proliferation. Taken together, our results show how MYC drives the production of specific eicosanoids critical for lung cancer cell survival and proliferation, with possible implications for the use of COX and LOX pathway inhibitors for lung cancer therapy. Cancer Res; 76(16); 4608–18. ©2016 AACR.
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- 2023
7. Supplementary Tables from Myc Expression Drives Aberrant Lipid Metabolism in Lung Cancer
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Julian L. Griffin, Gerard I. Evan, Trevor Littlewood, Albert Koulman, Tom Ashmore, Deborah L. Burkhart, Catherine H. Wilson, Zsuzsanna Ament, and Zoe Hall
- Abstract
LC-MS/MS method details for eicosanoid analysis (Tables S1 and S2); Lipid ID by accurate mass and tandem MS (Tables S3 and S4); Fold change for eicosanoid-related species with MYC activated (Table S5).
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- 2023
8. Therapeutically expanded human regulatory T-cells are super- suppressive due to HIF1A induced expression of CD73
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Lorna Jarvis, Daniel Rainbow, Valerie Coppard, Sarah Howlett, Jessica Davies, Harpreet Mullay, Joanna Hester, Tom Ashmore, Aletta Van Den Bosch, James Grist, Alasdair Coles, Hani Mousa, Stefano Pluchino, Krishnaa Mahbubani, Julian Griffin, Kourosh Saeb-Parsy, Fadi Issa, Luca Peruzzotti-Jametti, Linda Wicker, and Joanne Jones
- Abstract
The adoptive transfer of regulatory T-cells (Tregs) is a promising therapeutic approach in transplantation and autoimmunity. However, because large cell numbers are needed to achieve a therapeutic effect, in vitro expansion is required. By comparing their function, phenotype and transcriptomic profile against ex vivo Tregs, we demonstrate that expanded human Tregs switch their metabolism to aerobic glycolysis and show enhanced suppressive function through hypoxia-inducible factor 1-alpha (HIF1A) driven acquisition of CD73 expression. In conjunction with CD39, CD73 expression enables expanded Tregs to convert ATP to immunosuppressive adenosine. We conclude that for maximum therapeutic benefit, Treg expansion protocols should be optimised for CD39/CD73 co-expression
- Published
- 2020
9. Therapeutically expanded human regulatory T-cells are super-suppressive due to HIF1A induced expression of CD73
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Daniel B. Rainbow, Lorna B. Jarvis, Valerie Coppard, Hani S Mousa, Joanne L. Jones, Alasdair Coles, Zoya Georgieva, Fadi Issa, Kourosh Saeb-Parsy, Krishnaa T. Mahbubani, Stefano Pluchino, Tom Ashmore, Sarah Howlett, Julian L. Griffin, Luca Peruzzotti-Jametti, Linda S. Wicker, Aletta Van Den Bosch, Joanna Hester, Harpreet Kaur Mullay, James T. Grist, Jessica L. Davies, Jarvis, Lorna B [0000-0002-5760-0125], Rainbow, Daniel B [0000-0003-4931-3289], Davies, Jessica L [0000-0002-8888-1441], Hester, Joanna [0000-0002-7466-3849], Pluchino, Stefano [0000-0002-6267-9472], Mahbubani, Krishnaa T [0000-0002-1327-2334], Griffin, Julian L [0000-0003-1336-7744], Saeb-Parsy, Kourosh [0000-0002-0633-3696], Issa, Fadi [0000-0002-8279-7732], Wicker, Linda S [0000-0001-7771-0324], Jones, Joanne L [0000-0003-4974-1371], Apollo - University of Cambridge Repository, Mousa, Hani S [0000-0002-8327-7114], Jarvis, Lorna B. [0000-0002-5760-0125], Rainbow, Daniel B. [0000-0003-4931-3289], Davies, Jessica L. [0000-0002-8888-1441], Mahbubani, Krishnaa T. [0000-0002-1327-2334], Griffin, Julian L. [0000-0003-1336-7744], Wicker, Linda S. [0000-0001-7771-0324], and Jones, Joanne L. [0000-0003-4974-1371]
- Subjects
Male ,Adoptive cell transfer ,Autoimmune diseases ,Medicine (miscellaneous) ,medicine.disease_cause ,T-Lymphocytes, Regulatory ,Graft-versus-host disease ,Autoimmunity ,Transcriptome ,13/1 ,0302 clinical medicine ,Biology (General) ,631/250/24/1313 ,5'-Nucleotidase ,0303 health sciences ,631/250/24/1529 ,631/250/251/1574 ,hemic and immune systems ,Regulatory T cells ,3. Good health ,13/31 ,030220 oncology & carcinogenesis ,631/250/1619/554/1898/1271 ,38/39 ,64/60 ,Female ,General Agricultural and Biological Sciences ,medicine.drug ,QH301-705.5 ,13/106 ,chemical and pharmacologic phenomena ,Biology ,GPI-Linked Proteins ,General Biochemistry, Genetics and Molecular Biology ,Article ,03 medical and health sciences ,13/21 ,medicine ,Humans ,030304 developmental biology ,82 ,82/58 ,Hypoxia-Inducible Factor 1, alpha Subunit ,Adenosine ,Transplantation ,HIF1A ,Gene Expression Regulation ,Anaerobic glycolysis ,Cancer research ,Ex vivo ,Immunosuppression - Abstract
The adoptive transfer of regulatory T-cells (Tregs) is a promising therapeutic approach in transplantation and autoimmunity. However, because large cell numbers are needed to achieve a therapeutic effect, in vitro expansion is required. By comparing their function, phenotype and transcriptomic profile against ex vivo Tregs, we demonstrate that expanded human Tregs switch their metabolism to aerobic glycolysis and show enhanced suppressive function through hypoxia-inducible factor 1-alpha (HIF1A) driven acquisition of CD73 expression. In conjunction with CD39, CD73 expression enables expanded Tregs to convert ATP to immunosuppressive adenosine. We conclude that for maximum therapeutic benefit, Treg expansion protocols should be optimised for CD39/CD73 co-expression., Jarvis et al demonstrate that expanded human Tregs switch their metabolism to aerobic glycolysis and show enhanced suppressive function through hypoxia-inducible factor 1-alpha (HIF1A)-driven acquisition of CD73 expression, which along with CD39, enables expanded Tregs to convert ATP to immunosuppressive adenosine. Given this, the data suggests that Treg expansion protocols should be optimised for CD39/CD73 co-expression to enhance therapeutic potential.
- Published
- 2020
10. Myc linked to dysregulation of cholesterol transport and storage in nonsmall cell lung cancer
- Author
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Julian L. Griffin, Catherine H. Wilson, Zoe Hall, Tom Ashmore, Gerard I. Evan, Deborah L. Burkhart, Analytical Chemistry Trust Fund, and The Royal Society
- Subjects
0301 basic medicine ,Genetically modified mouse ,Biochemistry & Molecular Biology ,Lung Neoplasms ,Mice, Transgenic ,QD415-436 ,030204 cardiovascular system & hematology ,medicine.disease_cause ,0601 Biochemistry and Cell Biology ,Biochemistry ,Transcriptome ,Proto-Oncogene Proteins c-myc ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Endocrinology ,Lipid droplet ,Carcinoma, Non-Small-Cell Lung ,liquid extraction surface analysis ,lipid metabolism ,medicine ,Animals ,Lung cancer ,Lung ,Research Articles ,Cancer ,mass spectrometry ,adenocarcinoma ,Lipid metabolism ,Biological Transport ,Cell Biology ,medicine.disease ,respiratory tract diseases ,030104 developmental biology ,Cholesterol ,chemistry ,1101 Medical Biochemistry and Metabolomics ,Lipidomics ,cholesteryl ester ,Cholesteryl ester ,Cancer research ,Adenocarcinoma ,lipids (amino acids, peptides, and proteins) ,KRAS - Abstract
Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related deaths. Whilst mutations in Kras and over-expression of Myc are commonly found in patients, the role of altered lipid metabolism in lung cancer and its interplay with oncogenic Myc is poorly understood. Here we use a transgenic mouse model of Kras-driven lung adenocarcinoma with reversible activation of Myc, in combination with surface analysis lipid profiling of lung tumours and transcriptomics, to study the effect of Myc activity on cholesterol homeostasis. Our findings reveal that activation of Myc leads to the accumulation of cholesteryl esters (CE), stored in lipid droplets. Subsequent Myc deactivation leads to further increases in CEs, in contrast to tumours in which Myc was never activated. Gene expression analysis linked cholesterol transport and storage pathways to Myc activity. Our results suggest that increased Myc activity is associated with increased cholesterol influx, reduced efflux and accumulation of CE-rich lipid droplets in lung tumours. Targeting cholesterol homeostasis is proposed as a promising avenue to explore for novel treatments of lung cancer, with diagnostic and stratification potential in human NSCLC.
- Published
- 2020
11. The use of stable isotopes in the study of human pathophysiology
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Tom Ashmore, Evelina Charidemou, and Julian L. Griffin
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0301 basic medicine ,Biochemistry & Molecular Biology ,Protein digestion ,Biology ,0601 Biochemistry and Cell Biology ,Biochemistry ,03 medical and health sciences ,0302 clinical medicine ,Metabolomics ,Insulin resistance ,Metabolic Diseases ,Metabolic flux analysis ,Breath tests ,Metabolome ,medicine ,Humans ,Fluxomics ,chemistry.chemical_classification ,Metabolomics and stable isotopes ,Carbon Isotopes ,Gastric emptying ,Fatty acid ,Cell Biology ,Deuterium ,medicine.disease ,Metabolism ,030104 developmental biology ,1101 Medical Biochemistry and Metabolomics ,chemistry ,1116 Medical Physiology ,030217 neurology & neurosurgery - Abstract
The growing prevalence of metabolic diseases including fatty liver disease and Type 2 diabetes has increased the emphasis on understanding metabolism at the mechanistic level and how it is perturbed in disease. Metabolomics is a continually expanding field that seeks to measure metabolites in biological systems during a physiological stimulus or a genetic alteration. Typically, metabolomics studies provide total pool sizes of metabolites rather than dynamic flux measurements. More recently there has been a resurgence in approaches that use stable isotopes (e.g. 2H and 13C) for the unambiguous tracking of individual atoms through compartmentalised metabolic networks in humans to determine underlying mechanisms. This is known as metabolic flux analysis and enables the capture of a dynamic picture of the metabolome and its interactions with the genome and proteome. In this review, we describe current approaches using stable isotope labelling in the field of metabolomics and provide examples of studies that led to an improved understanding of glucose, fatty acid and amino acid metabolism in humans, particularly in relation to metabolic disease. Examples include the use of stable isotopes of glucose to study tumour bioenergetics as well as brain metabolism during traumatic brain injury. Lipid tracers have also been used to measure non-esterified fatty acid production whilst amino acid tracers have been used to study the rate of protein digestion on whole body postprandial protein metabolism. In addition, we illustrate the use of stable isotopes for measuring flux in human physiology by providing examples of breath tests to measure insulin resistance and gastric emptying rates.
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- 2017
12. Lipid zonation and phospholipid remodeling in nonalcoholic fatty liver disease
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Susan E. Davies, Sam Virtue, Xinzhu Wang, Zoe Hall, Francis Sanders, Andrew J. Murray, Julian L. Griffin, Nicholas J. Bond, Elena Bellafante, Tom Ashmore, Zsuzsanna Ament, Michael Allison, Michele Vacca, Antonio Vidal-Puig, Albert Koulman, Koulman, Albert [0000-0001-9998-051X], and Apollo - University of Cambridge Repository
- Subjects
0301 basic medicine ,Liver Cirrhosis ,Male ,Cirrhosis ,Severity of Illness Index ,Mass Spectrometry ,chemistry.chemical_compound ,Steatohepatitis/Metabolic Liver Disease ,Mice ,Random Allocation ,Non-alcoholic Fatty Liver Disease ,Nonalcoholic fatty liver disease ,Phospholipids ,Fatty liver ,Biopsy, Needle ,Liver Neoplasms ,Non‐alcoholic Steatohepatitis ,Prognosis ,Immunohistochemistry ,Liver regeneration ,3. Good health ,Biochemistry ,Lipotoxicity ,Metabolic Pathways ,medicine.medical_specialty ,Phospholipid ,Biology ,Diet, High-Fat ,Risk Assessment ,03 medical and health sciences ,Internal medicine ,Lipidomics ,1101 Medical Biochemistry And Metabolomics ,medicine ,Animals ,Humans ,Gastroenterology & Hepatology ,Hepatology ,1103 Clinical Sciences ,medicine.disease ,Non‐alcoholic Fatty Liver Disease ,digestive system diseases ,Liver Regeneration ,Fatty Liver ,Mice, Inbred C57BL ,Disease Models, Animal ,030104 developmental biology ,Endocrinology ,chemistry ,Eicosanoid ,Diet, Western ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Eicosanoids - Abstract
UNLABELLED: Nonalcoholic fatty liver disease (NAFLD) can progress from simple steatosis (i.e., nonalcoholic fatty liver [NAFL]) to nonalcoholic steatohepatitis (NASH), cirrhosis, and cancer. Currently, the driver for this progression is not fully understood; in particular, it is not known how NAFLD and its early progression affects the distribution of lipids in the liver, producing lipotoxicity and inflammation. In this study, we used dietary and genetic mouse models of NAFL and NASH and translated the results to humans by correlating the spatial distribution of lipids in liver tissue with disease progression using advanced mass spectrometry imaging technology. We identified several lipids with distinct zonal distributions in control and NAFL samples and observed partial to complete loss of lipid zonation in NASH. In addition, we found increased hepatic expression of genes associated with remodeling the phospholipid membrane, release of arachidonic acid (AA) from the membrane, and production of eicosanoid species that promote inflammation and cell injury. The results of our immunohistochemistry analyses suggest that the zonal location of remodeling enzyme LPCAT2 plays a role in the change in spatial distribution for AA-containing lipids. This results in a cycle of AA-enrichment in pericentral hepatocytes, membrane release of AA, and generation of proinflammatory eicosanoids and may account for increased oxidative damage in pericentral regions in NASH. CONCLUSION: NAFLD is associated not only with lipid enrichment, but also with zonal changes of specific lipids and their associated metabolic pathways. This may play a role in the heterogeneous development of NAFLD. (Hepatology 2017;65:1165-1180).
- Published
- 2017
13. Inorganic Nitrate Mimics Exercise-Stimulated Muscular Fiber-Type Switching and Myokine and γ-Aminobutyric Acid Release
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Elizabeth A. Williams, Martin Feelisch, Julian L. Griffin, Ben D. McNally, Mario Siervo, Steven A. Murfitt, Tom Ashmore, Andrew J. Murray, Ross T. Lindsay, Lee D. Roberts, and Bernadette O. Fernandez
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Male ,0301 basic medicine ,Aminoisobutyric Acids ,Endocrinology, Diabetes and Metabolism ,Muscle Fibers, Skeletal ,Mass Spectrometry ,Mice ,0302 clinical medicine ,Adipocytes ,Glycolysis ,Receptor ,gamma-Aminobutyric Acid ,Myogenesis ,Middle Aged ,Immunohistochemistry ,Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ,FNDC5 ,Fruit and Vegetable Juices ,Muscle Fibers, Slow-Twitch ,medicine.anatomical_structure ,Muscle Fibers, Fast-Twitch ,Female ,Beta vulgaris ,medicine.medical_specialty ,Mice, Transgenic ,In Vitro Techniques ,Biology ,Aminobutyric acid ,Gas Chromatography-Mass Spectrometry ,03 medical and health sciences ,Insulin resistance ,Double-Blind Method ,Physical Conditioning, Animal ,Internal medicine ,Myokine ,Internal Medicine ,medicine ,Animals ,Humans ,Rats, Wistar ,Muscle, Skeletal ,Aged ,Nitrates ,Skeletal muscle ,medicine.disease ,Fibronectins ,Rats ,030104 developmental biology ,Endocrinology ,Growth Hormone ,Insulin Resistance ,Transcriptome ,030217 neurology & neurosurgery ,Chromatography, Liquid - Abstract
Exercise is an effective intervention for the prevention and treatment of type 2 diabetes. Skeletal muscle combines multiple signals that contribute to the beneficial effects of exercise on cardiometabolic health. Inorganic nitrate increases exercise efficiency, tolerance, and performance. The transcriptional regulator peroxisome proliferator–activated receptor γ coactivator 1α (PGC1α) coordinates the exercise-stimulated skeletal muscle fiber-type switch from glycolytic fast-twitch (type IIb) to oxidative slow-twitch (type I) and intermediate (type IIa) fibers, an effect reversed in insulin resistance and diabetes. We found that nitrate induces PGC1α expression and a switch toward type I and IIa fibers in rat muscle and myotubes in vitro. Nitrate induces the release of exercise/PGC1α-dependent myokine FNDC5/irisin and β-aminoisobutyric acid from myotubes and muscle in rats and humans. Both exercise and nitrate stimulated PGC1α-mediated γ-aminobutyric acid (GABA) secretion from muscle. Circulating GABA concentrations were increased in exercising mice and nitrate-treated rats and humans; thus, GABA may function as an exercise/PGC1α-mediated myokine-like small molecule. Moreover, nitrate increased circulating growth hormone levels in humans and rodents. Nitrate induces physiological responses that mimic exercise training and may underlie the beneficial effects of this metabolite on exercise and cardiometabolic health.
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- 2016
14. Nutritional Ketosis Alters Fuel Preference and Thereby Endurance Performance in Athletes
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Alan Smith, Tom Ashmore, Andrew J. Murray, Julian L. Griffin, Brianna J. Stubbs, Scott Drawer, Rhys D. Evans, Stefan Neubauer, Tom Kirk, Pete J. Cox, Kieran Clarke, Richard L. Veech, Stewart W. McLure, James A. West, Cameron J. Holloway, Kristof Willerton, M. Todd King, Michael S. Dodd, Murray, Andrew [0000-0002-0929-9315], West, James [0000-0002-1535-7737], Griffin, Julian [0000-0003-1336-7744], and Apollo - University of Cambridge Repository
- Subjects
Male ,0301 basic medicine ,medicine.medical_specialty ,Physiology ,Rest ,Carbohydrates ,Ketone Bodies ,Oxidative phosphorylation ,0601 Biochemistry and Cell Biology ,Endocrinology & Metabolism ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Carnitine ,Internal medicine ,medicine ,Humans ,Glycolysis ,Exercise physiology ,Muscle, Skeletal ,Exercise ,Molecular Biology ,Adiposity ,Glycogen ,Chemistry ,Ketosis ,030229 sport sciences ,Cell Biology ,Metabolism ,Carbohydrate ,medicine.disease ,Diet ,030104 developmental biology ,Endocrinology ,1101 Medical Biochemistry and Metabolomics ,Athletes ,Physical Endurance ,Ketone bodies ,Female ,Energy Metabolism - Abstract
Ketosis, the metabolic response to energy crisis, is a mechanism to sustain life by altering oxidative fuel selection. Often overlooked for its metabolic potential, ketosis is poorly understood outside of starvation or diabetic crisis. Thus, we studied the biochemical advantages of ketosis in humans using a ketone ester-based form of nutrition without the unwanted milieu of endogenous ketone body production by caloric or carbohydrate restriction. In five separate studies of 39 high-performance athletes, we show how this unique metabolic state improves physical endurance by altering fuel competition for oxidative respiration. Ketosis decreased muscle glycolysis and plasma lactate concentrations, while providing an alternative substrate for oxidative phosphorylation. Ketosis increased intramuscular triacylglycerol oxidation during exercise, even in the presence of normal muscle glycogen, co-ingested carbohydrate and elevated insulin. These findings may hold clues to greater human potential and a better understanding of fuel metabolism in health and disease.
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- 2016
15. PPAR-pan activation induces hepatic oxidative stress and lipidomic remodelling
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Jayne Wright, Tom Ashmore, Andrew W. Nicholls, Elizabeth Stanley, Zsuzsanna Ament, James A. West, Lee D. Roberts, and Julian L. Griffin
- Subjects
0301 basic medicine ,Agonist ,medicine.medical_specialty ,Peroxisome proliferator-activated receptors ,medicine.drug_class ,Peroxisome proliferator-activated receptor ,β-Oxidation ,Fatty Acids, Nonesterified ,Pharmacology ,Biology ,medicine.disease_cause ,Biochemistry ,PPAR agonist ,Rats, Sprague-Dawley ,03 medical and health sciences ,Physiology (medical) ,Internal medicine ,medicine ,Animals ,Metabolomics ,PPAR alpha ,Receptor ,PPAR-beta ,chemistry.chemical_classification ,Lipid metabolism ,Original Contribution ,Lipid Metabolism ,Lipids ,Rats ,3. Good health ,PPAR gamma ,Oxidative Stress ,030104 developmental biology ,Endocrinology ,Diabetes Mellitus, Type 2 ,Liver ,Eicosanoid ,Nuclear receptor ,chemistry ,Lipidomics ,Eicosanoids ,lipids (amino acids, peptides, and proteins) ,Oxidative stress - Abstract
The peroxisome proliferator-activated receptors (PPARs) are ligand activated nuclear receptors that regulate cellular homoeostasis and metabolism. PPARs control the expression of genes involved in fatty-acid and lipid metabolism. Despite evidence showing beneficial effects of their activation in the treatment of metabolic diseases, particularly dyslipidaemias and type 2 diabetes, PPAR agonists have also been associated with a variety of side effects and adverse pathological changes. Agonists have been developed that simultaneously activate the three PPAR receptors (PPARα, γ and δ) in the hope that the beneficial effects can be harnessed while avoiding some of the negative side effects. In this study, the hepatic effects of a discontinued PPAR-pan agonist (a triple agonist of PPAR-α, -γ, and -δ), was investigated after dietary treatment of male Sprague–Dawley (SD) rats. The agonist induced liver enlargement in conjunction with metabolomic and lipidomic remodelling. Increased concentrations of several metabolites related to processes of oxidation, such as oxo-methionine, methyl-cytosine and adenosyl-methionine indicated increased stress and immune status. These changes are reflected in lipidomic changes, and increased energy demands as determined by free fatty acid (decreased 18:3 n−3, 20:5 n−3 and increased ratios of n−6/n−3 fatty acids) triacylglycerol, phospholipid (decreased and increased bulk changes respectively) and eicosanoid content (increases in PGB2 and 15-deoxy PGJ2). We conclude that the investigated PPAR agonist, GW625019, induces liver enlargement, accompanied by lipidomic remodelling, oxidative stress and increases in several pro-inflammatory eicosanoids. This suggests that such pathways should be monitored in the drug development process and also outline how PPAR agonists induce liver proliferation., Highlights • The investigated PPAR-pan agonist increased oxidative damage in the rat liver. • Metabolomics can be used to follow the dose response nature of PPAR-pan agonists. • Metabolomics is a versatile tool in following oxidative stress.
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- 2016
16. Metabolomics dataset of PPAR-pan treated rat liver
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James A. West, Tom Ashmore, Xuefei Li, Elizabeth Stanley, Andrew W. Nicholls, Lee D. Roberts, Zsuzsanna Ament, Julian L. Griffin, and Jayne Wright
- Subjects
0301 basic medicine ,Analyte ,education ,Peroxisome proliferator-activated receptor ,lcsh:Computer applications to medicine. Medical informatics ,Mass spectrometry ,PPAR ,03 medical and health sciences ,Metabolomics ,Lipidomics ,lcsh:Science (General) ,Data Article ,chemistry.chemical_classification ,Peroxisome proliferator activated receptors ,Multidisciplinary ,Chromatography ,Mass-to-charge ratio ,Chemistry ,Fatty acid ,Peroxisome ,030104 developmental biology ,lcsh:R858-859.7 ,lcsh:Q1-390 - Abstract
This article contains mass spectrometry (MS) data investigating small molecule changes as an effect of a triple peroxisome proliferator-activated receptor (PPAR-pan) agonist GW625019 in the liver as described in the manuscript (Ament et al., 2016) [1]. Samples were measured using gas chromatography-mass spectrometry (GC–MS) for total fatty acid content, and liquid chromatography-mass spectrometry (LC–MS) to measure intact lipids, carnitines and selected aqueous metabolites and eicosanoids. Data files comprise of Excel (Microsoft, WA, USA) spreadsheets of identified metabolites and their area ratio values for total fatty acids, carnitines, aqueous metabolites, and eicosanoids where the intensity of the analytes were normalised to the intensity of the internal standard. In the case of open profiling intact lipid data, the Excel file contains area ratio values of retention time and mass to charge ratio pairs; again, the area ratio values were calculated by normalising to the intensity of the internal standard. It should be noted that several metabolic changes are potentially indirect (secondary, tertiary and ensuing changes). Keywords: Peroxisome proliferator activated receptors, PPAR, Metabolomics, Lipidomics, Mass spectrometry
- Published
- 2016
17. A randomized 3-way crossover study indicates that high-protein feeding induces de novo lipogenesis in healthy humans
- Author
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Elise R. Orford, Xuefei Li, Sonia Liggi, Evelina Charidemou, Julian L. Griffin, Tom Ashmore, Matthew Harvey, Ben D. McNally, and James A. West
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0301 basic medicine ,Male ,Administration, Oral ,Research & Experimental Medicine ,APOC-III ,0302 clinical medicine ,Non-alcoholic Fatty Liver Disease ,ATP-CITRATE LYASE ,SPECTROMETRY DATA ,Insulin ,Amino Acids ,2. Zero hunger ,INSULIN-RESISTANCE ,biology ,Chemistry ,FOXO1 ,Diabetes ,General Medicine ,Healthy Volunteers ,AMINO-ACID ,Medicine, Research & Experimental ,Liver ,030220 oncology & carcinogenesis ,Lipogenesis ,Diet, High-Protein ,FATTY-ACIDS ,Dietary Proteins ,Leucine ,Life Sciences & Biomedicine ,Adult ,medicine.medical_specialty ,Amino acid metabolism ,03 medical and health sciences ,Young Adult ,Insulin resistance ,Internal medicine ,medicine ,Humans ,Obesity ,HEPATIC STEATOSIS ,Protein kinase B ,Triglycerides ,Science & Technology ,Metabolism ,Feeding Behavior ,medicine.disease ,Glutamine ,Insulin receptor ,030104 developmental biology ,Endocrinology ,Diabetes Mellitus, Type 2 ,biology.protein ,Hepatocytes ,HIGH-CARBOHYDRATE ,Insulin Resistance ,Clinical Medicine ,Lipoprotein - Abstract
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)., A subset of amino acids may induce de novo lipogenesis in humans, suggesting that use of high-protein diets to tackle diabetes requires greater consideration.
- Published
- 2018
18. Oral Coenzyme Q10 Supplementation Does Not Prevent Cardiac Alterations During a High Altitude Trek to Everest Base Camp
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Hugh Montgomery, Michael P.W. Grocott, Sundeep Dhillon, Daniel Martin, Lowri E. Cochlin, Ion Codreanu, Stefan Neubauer, George W. Rodway, Cameron J. Holloway, Denny Z. H. Levett, Kay Mitchell, Kieran Clarke, Tom Ashmore, Andrew J. Murray, and Andrew W Johnson
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Adult ,Male ,Scientific Articles ,medicine.medical_specialty ,Ubiquinone ,Physiology ,Cardiac Volume ,Heart Ventricles ,Diastole ,Administration, Oral ,Adipose tissue ,Blood Pressure ,Oxidative phosphorylation ,Biology ,Antioxidants ,Body Mass Index ,Phosphates ,chemistry.chemical_compound ,Internal medicine ,medicine ,Humans ,Coenzyme Q10 ,Public Health, Environmental and Occupational Health ,Vitamins ,General Medicine ,Middle Aged ,Hypoxia (medical) ,Effects of high altitude on humans ,Magnetic Resonance Imaging ,Cell Hypoxia ,Mountaineering ,Endocrinology ,Blood pressure ,Adipose Tissue ,chemistry ,Echocardiography ,Dietary Supplements ,Female ,medicine.symptom ,human activities ,Body mass index - Abstract
Holloway, Cameron J., Andrew J. Murray, Kay Mitchell, Daniel S. Martin, Andrew W. Johnson, Lowri E. Cochlin, Ion Codreanu, Sundeep Dhillon, George W. Rodway, Tom Ashmore, Denny Z.H. Levett, Stefan Neubauer, Hugh E. Montgomery, Michael P.W. Grocott, and Kieran Clarke, on behalf of the Caudwell Xtreme Everest 2009 Investigators. Oral Coenzyme Q supplementation does not prevent cardiac alterations during a high altitude trek to Everest Base Camp. High Alt Med Biol 15:000—000, 2014.—Exposure to high altitude is associated with sustained, but reversible, changes in cardiac mass, diastolic function, and high-energy phosphate metabolism. Whilst the underlying mechanisms remain elusive, tissue hypoxia increases generation of reactive oxygen species (ROS), which can stabilize hypoxia-inducible factor (HIF) transcription factors, bringing about transcriptional changes that suppress oxidative phosphorylation and activate autophagy. We therefore investigated whether oral supplementation with an antioxidant, Coenzyme Q10, prevented the cardiac perturbations associated with altitude exposure. Twenty-three volunteers (10 male, 13 female, 46±3 years) were recruited from the 2009 Caudwell Xtreme Everest Research Treks and studied before, and within 48 h of return from, a 17-day trek to Everest Base Camp, with subjects receiving either no intervention (controls) or 300 mg Coenzyme Q10 per day throughout altitude exposure. Cardiac magnetic resonance imaging and echocardiography were used to assess cardiac morphology and function. Following altitude exposure, body mass fell by 3 kg in all subjects (p
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- 2014
19. SUN-LB329: Liquid Carbohydrate Content of Meals is a Major Determinant of Gastric Emptying Rate
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Matthew Harvey, X. Li, S. Wassell, Evelina Charidemou, Ben D. McNally, Jules L. Griffin, Tom Ashmore, Elise R. Orford, and Michelle C. Venables
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Carbohydrate content ,Nutrition and Dietetics ,Gastric emptying ,business.industry ,Medicine ,Food science ,Critical Care and Intensive Care Medicine ,business - Published
- 2017
20. Suppression of erythropoiesis by dietary nitrate
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Tom, Ashmore, Bernadette O, Fernandez, Colin E, Evans, Yun, Huang, Cristina, Branco-Price, Julian L, Griffin, Randall S, Johnson, Martin, Feelisch, and Andrew J, Murray
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Male ,kidney ,Nitrates ,hypoxia ,oxygen sensing ,Hypoxia-Inducible Factor 1, alpha Subunit ,Recombinant Proteins ,Rats ,Epoetin Alfa ,Immunoenzyme Techniques ,Oxygen ,Hemoglobins ,Research Communication ,Liver ,Dietary Supplements ,Animals ,Erythropoiesis ,Rats, Wistar ,Erythropoietin - Abstract
In mammals, hypoxia-triggered erythropoietin release increases red blood cell mass to meet tissue oxygen demands. Using male Wistar rats, we unmask a previously unrecognized regulatory pathway of erythropoiesis involving suppressor control by the NO metabolite and ubiquitous dietary component nitrate. We find that circulating hemoglobin levels are modulated by nitrate at concentrations achievable by dietary intervention under normoxic and hypoxic conditions; a moderate dose of nitrate administered via the drinking water (7 mg NaNO3/kg body weight/d) lowered hemoglobin concentration and hematocrit after 6 d compared with nonsupplemented/NaCl-supplemented controls. The underlying mechanism is suppression of hepatic erythropoietin expression associated with the downregulation of tissue hypoxia markers, suggesting increased pO2. At higher nitrate doses, however, a partial reversal of this effect occurred; this was accompanied by increased renal erythropoietin expression and stabilization of hypoxia-inducible factors, likely brought about by the relative anemia. Thus, hepatic and renal hypoxia-sensing pathways act in concert to modulate hemoglobin in response to nitrate, converging at an optimal minimal hemoglobin concentration appropriate to the environmental/physiologic situation. Suppression of hepatic erythropoietin expression by nitrate may thus act to decrease blood viscosity while matching oxygen supply to demand, whereas renal oxygen sensing could act as a brake, averting a potentially detrimental fall in hematocrit.—Ashmore, T., Fernandez, B. O., Evans, C. E., Huang, Y., Branco-Price, C., Griffin, J. L., Johnson, R. S., Feelisch, M., Murray, A. J. Suppression of erythropoiesis by dietary nitrate.
- Published
- 2014
21. Inorganic Nitrate Promotes the Browning of White Adipose Tissue through the Nitrate-Nitrite-Nitric Oxide Pathway
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Martin Feelisch, Andrew J. Murray, Bernadette O. Fernandez, Tom Ashmore, Julian L. Griffin, Aleksandra O. Kotwica, Lee D. Roberts, and Steven A. Murfitt
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Male ,medicine.medical_specialty ,Adipose Tissue, White ,Endocrinology, Diabetes and Metabolism ,Adipose tissue macrophages ,Adipocytes, White ,Adipose tissue ,White adipose tissue ,Biology ,Nitric Oxide ,Article ,Nitric oxide ,Endocrinology & Metabolism ,Mice ,chemistry.chemical_compound ,Adipose Tissue, Brown ,Nitrate ,Internal medicine ,Brown adipose tissue ,Cyclic GMP-Dependent Protein Kinases ,Internal Medicine ,medicine ,Browning ,Animals ,Rats, Wistar ,Cyclic GMP ,11 Medical and Health Sciences ,Cells, Cultured ,Nitrites ,PRDM16 ,Nitrates ,Dose-Response Relationship, Drug ,Rats ,Mice, Inbred C57BL ,Adipocytes, Brown ,medicine.anatomical_structure ,Endocrinology ,chemistry ,Biochemistry - Abstract
Inorganic nitrate was once considered an oxidation end product of nitric oxide metabolism with little biological activity. However, recent studies have demonstrated that dietary nitrate can modulate mitochondrial function in man and is effective in reversing features of the metabolic syndrome in mice. Using a combined histological, metabolomics, and transcriptional and protein analysis approach, we mechanistically defined that nitrate not only increases the expression of thermogenic genes in brown adipose tissue but also induces the expression of brown adipocyte–specific genes and proteins in white adipose tissue, substantially increasing oxygen consumption and fatty acid β-oxidation in adipocytes. Nitrate induces these phenotypic changes through a mechanism distinct from known physiological small molecule activators of browning, the recently identified nitrate-nitrite-nitric oxide pathway. The nitrate-induced browning effect was enhanced in hypoxia, a serious comorbidity affecting white adipose tissue in obese individuals, and corrected impaired brown adipocyte–specific gene expression in white adipose tissue in a murine model of obesity. Because resulting beige/brite cells exhibit antiobesity and antidiabetic effects, nitrate may be an effective means of inducing the browning response in adipose tissue to treat the metabolic syndrome.
- Published
- 2014
22. Dietary nitrate increases arginine availability and protects mitochondrial complex I and energetics in the hypoxic rat heart
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James A. West, Martin Feelisch, Randall S. Johnson, Andrew J. Murray, Tom Ashmore, Cristina Branco-Price, Lisa C. Heather, Andrew S. Cowburn, Julian L. Griffin, Bernadette O. Fernandez, Mendes Branco, Cristina Branco [0000-0001-6953-4922], West, James [0000-0002-1535-7737], Cowburn, Andrew [0000-0001-9145-4275], Griffin, Julian [0000-0003-1336-7744], Johnson, Randall [0000-0002-4084-6639], Murray, Andrew [0000-0002-0929-9315], and Apollo - University of Cambridge Repository
- Subjects
Male ,HIGH-ALTITUDE HYPOXIA ,Arginine ,Physiology ,ENERGY-METABOLISM ,medicine.disease_cause ,Cardiovascular ,chemistry.chemical_compound ,Nitrate ,11 Medical and Health Sciences ,S-NITROSATION ,Cardiac muscle ,Heart ,Arginase ,medicine.anatomical_structure ,SKELETAL-MUSCLE ,INORGANIC NITRATE ,Hypoxia-Inducible Factor 1 ,medicine.symptom ,METABOLIC ADAPTATION ,Life Sciences & Biomedicine ,medicine.medical_specialty ,Protein Carbonylation ,Biology ,OBSTRUCTIVE PULMONARY-DISEASE ,MECHANISMS ,Internal medicine ,Respiration ,medicine ,Animals ,Rats, Wistar ,Nitrites ,Science & Technology ,NITRIC-OXIDE ,Electron Transport Complex I ,Nitrates ,BLOOD-FLOW ,Myocardium ,Neurosciences ,06 Biological Sciences ,Diet ,Rats ,Oxygen ,Oxidative Stress ,Endocrinology ,Mechanism of action ,chemistry ,Gene Expression Regulation ,Neurosciences & Neurology ,Oxidative stress - Abstract
Hypoxic exposure is associated with impaired cardiac energetics in humans and altered mitochondrial function, with suppressed complex I-supported respiration, in rat heart. This response might limit reactive oxygen species generation, but at the cost of impaired electron transport chain (ETC) activity. Dietary nitrate supplementation improves mitochondrial efficiency and can promote tissue oxygenation by enhancing blood flow. We therefore hypothesised that ETC dysfunction, impaired energetics and oxidative damage in the hearts of rats exposed to chronic hypoxia could be alleviated by sustained administration of a moderate dose of dietary nitrate. Male Wistar rats (n = 40) were given water supplemented with 0.7 mmol l(-1) NaCl (as control) or 0.7 mmol l(-1) NaNO3, elevating plasma nitrate levels by 80%, and were exposed to 13% O2 (hypoxia) or normoxia (n = 10 per group) for 14 days. Respiration rates, ETC protein levels, mitochondrial density, ATP content and protein carbonylation were measured in cardiac muscle. Complex I respiration rates and protein levels were 33% lower in hypoxic/NaCl rats compared with normoxic/NaCl controls. Protein carbonylation was 65% higher in hearts of hypoxic rats compared with controls, indicating increased oxidative stress, whilst ATP levels were 62% lower. Respiration rates, complex I protein and activity, protein carbonylation and ATP levels were all fully protected in the hearts of nitrate-supplemented hypoxic rats. Both in normoxia and hypoxia, dietary nitrate suppressed cardiac arginase expression and activity and markedly elevated cardiac l-arginine concentrations, unmasking a novel mechanism of action by which nitrate enhances tissue NO bioavailability. Dietary nitrate therefore alleviates metabolic abnormalities in the hypoxic heart, improving myocardial energetics.
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- 2014
23. 180 Early Life Exposure to Maternal Obesity Perturbs Renal Morphology in Mice
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Susan E. Ozanne, Tom Ashmore, Heather L. Blackmore, and Adele G. Pinnock
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medicine.medical_specialty ,Kidney ,Pregnancy ,Offspring ,business.industry ,Type 2 diabetes ,Glomerular Hypertrophy ,medicine.disease ,medicine.anatomical_structure ,Endocrinology ,Internal medicine ,medicine ,Gestation ,Metabolic syndrome ,Cardiology and Cardiovascular Medicine ,business ,Kidney disease - Abstract
Introduction The incidence of Chronic Kidney Disease (CKD) has risen globally by 83% since 1990, concurrently with type 2 diabetes and metabolic syndrome. Studies of maternal under-nutrition during pregnancy have highlighted that the kidney can be adversely “programmed” resulting in fewer filtration units, a factor linked to the pathogenesis of CKD, hypertension and cardiovascular disease (CVD). Despite the dramatic increase in obesity in recent years, the effect of maternal over-nutrition/obesity during pregnancy on offspring kidney structure and function remains largely unexplored. The aim of the current study was to define the effects of maternal over-nutrition on offspring kidney structure using a mouse model of maternal diet-induced obesity. Methods Female C57BL/6 mice were fed a high fat diet supplemented with sweetened condensed milk for six weeks prior to pregnancy and throughout gestation and lactation. This led to a doubling in maternal body fat. Male offspring were studied at 3 weeks of age. Kidneys were harvested, sectioned and stained with Haematoxylin and Eosin. Nephrons were counted in whole sections at even interspaces throughout the kidney to estimate the number of nephrons within a given area. Glomeruli diameters were also measured as an indicator of glomerular area. Results There was no difference in absolute kidney weight between the 2 offspring groups (p = 0.95). Offspring exposed to a maternal obesogenic diet had significantly larger combined renal cortex and medulla areas than offspring exposed to a maternal chow diet (17.4 mm 2 vs 12.5 mm 2 respectively [p = 0.0136]). However, the number of nephrons/mm 2 within the cortex and medulla was significantly reduced in offspring of obese pregnancies when compared to controls (2.2/mm 2 vs. 3.5/mm 2 respectively [p = 0.0047]). The mean glomerulus diameter was also significantly larger within offspring of obese pregnancies compared with offspring of control pregnancies (53.7 um vs. 46.3 um respectively [p Conclusions These results suggest that there is compensatory individual glomerular hypertrophy due to a reduced glomeruli density in offspring exposed to maternal obesity during pregnancy and lactation, and that these individuals may therefore be more at risk of developing renal disease and associated CVD in later life. These findings highlight the importance of further studying the long-term consequences of these early morphological changes.
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- 2016
24. Response to Comment on Lee et al. Diabetes 2015;64:2836–2846. Comment on Roberts et al. Diabetes 2015;64:471–484
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Andrew J. Murray, Tom Ashmore, Julian L. Griffin, and Lee D. Roberts
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Male ,0301 basic medicine ,medicine.medical_specialty ,Nitric Oxide Synthase Type III ,Adipose Tissue, White ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Inflammation ,Nitric Oxide ,Nitric oxide ,03 medical and health sciences ,chemistry.chemical_compound ,Nitrate ,In vivo ,Internal medicine ,Internal Medicine ,medicine ,Animals ,Nitrite ,Nitrites ,Nitrates ,Chemistry ,Macrophages ,Insulin ,Cell Polarity ,030104 developmental biology ,Endocrinology ,Phosphoprotein ,Endothelium, Vascular ,medicine.symptom - Abstract
In their letter, Kruszelnicka and Surdacki (1) suggested that the liver is likely to be exposed to high concentrations of ingested inorganic nitrate. In vivo, nitrate can be serially reduced to nitrite and then nitric oxide (NO). Lee et al. (2) recently demonstrated that NO promoted a vasodilator-stimulated phosphoprotein (VASP)-mediated switch in hepatic macrophages toward the anti-inflammatory M2 phenotype, reducing inflammation and relieving insulin …
- Published
- 2016
25. Cryopreservation of placental biopsies for mitochondrial respiratory analysis
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Andrew J. Murray, Andrea J. Morash, M. Monk, F. Colleoni, Tom Ashmore, and Graham J. Burton
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Cryopreservation ,medicine.diagnostic_test ,Biopsy ,Placenta ,Cell Respiration ,Obstetrics and Gynecology ,Anatomy ,Biology ,Mitochondrion ,Mitochondria ,Andrology ,Respirometry ,medicine.anatomical_structure ,Reproductive Medicine ,Pregnancy ,Respiration ,medicine ,Humans ,Female ,Respiratory system ,Function (biology) ,Developmental Biology - Abstract
Mitochondrial function is required to support energetically-demanding processes in the placenta. As such, a compromise in mitochondrial function could severely impact fetal growth and development. Respirometry is a highly useful method for studying mitochondrial function, but is not possible in freeze-thawed mitochondria, which become uncoupled. We have developed a novel method that permits respiratory analysis of cryopreserved placental tissue. We studied mitochondrial function in 7 normal human placentas, analysing both fresh and cryopreserved samples. We found no impairments in respiration following cryopreservation in the delivery suite, with enhanced coupling, as indicated by higher respiratory control ratios, than in fresh placental samples transported to the laboratory on ice.
- Published
- 2011
26. The contrasting roles of PPARδ and PPARγ in regulating the metabolic switch between oxidation and storage of fats in white adipose tissue
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Lee D. Roberts, Andrew W. Nicholls, Tom Ashmore, David A. Menassa, Andrew J. Murray, Julian L. Griffin, Murray, Andrew [0000-0002-0929-9315], Griffin, Julian [0000-0003-1336-7744], and Apollo - University of Cambridge Repository
- Subjects
Male ,Magnetic Resonance Spectroscopy ,Bioinformatics ,Adipose Tissue, White ,05 Environmental Sciences ,Mice, Obese ,Receptors, Cytoplasmic and Nuclear ,Peroxisome proliferator-activated receptor ,Adipose tissue ,White adipose tissue ,Biology ,Mice ,03 medical and health sciences ,0302 clinical medicine ,3T3-L1 Cells ,Adipocytes ,Animals ,Metabolomics ,PPAR delta ,Receptor ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,Research ,Fatty acid ,06 Biological Sciences ,Peroxisome ,Lipid Metabolism ,PPAR gamma ,Nuclear receptor ,chemistry ,Biochemistry ,Peroxisome proliferator-activated receptor delta ,08 Information and Computing Sciences ,Insulin Resistance ,Oxidation-Reduction ,030217 neurology & neurosurgery - Abstract
Background: The nuclear receptors peroxisome proliferator-activated receptor γ (PPARγ) and peroxisome proliferator-activated receptor δ (PPARδ) play central roles in regulating metabolism in adipose tissue, as well as being targets for the treatment of insulin resistance. While the role of PPARγ in regulating insulin sensitivity has been well defined, research into PPARδ has been limited until recently due to a scarcity of selective PPARδ agonists.Results: The metabolic effects of PPARγ and PPARδ activation have been examined in vivo in white adipose tissue from ob/ob mice and in vitro in cultured 3T3-L1 adipocytes using 1H nuclear magnetic resonance spectroscopy and mass spectrometry metabolomics to understand the receptors' contrasting roles. These steady state measurements were supplemented with 13C-stable isotope substrate labeling to assess fluxes, in addition to respirometry and transcriptomic microarray analysis. The metabolic effects of the receptors were readily distinguished, with PPARγ activation characterized by increased fat storage, synthesis and elongation, while PPARδ activation caused increased fatty acid β-oxidation, tricarboxylic acid cycle rate and oxidation of extracellular branch chain amino acids. Stimulated glycolysis and increased fatty acid desaturation were common pathways for the agonists.Conclusions: PPARγ and PPARδ restore insulin sensitivity through varying mechanisms. PPARδ activation increases total oxidative metabolism in white adipose tissue, a tissue not traditionally thought of as oxidative. However, the increased metabolism of branch chain amino acids may provide a mechanism for muscle atrophy, which has been linked to activation of this nuclear receptor. PPARδ has a role as an anti-obesity target and as an anti-diabetic, and hence may target both the cause and consequences of dyslipidemia.
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