Metabolomic Research (PDF) - University of Leeds

Metabolomics/MetabonomicsMetabolomics/metabonomics is the term applied to the quantitative measurement of themetabolic response of living systems to pathophysiologic stimuli or genetic modification 1 ,and the approach interfaces with the other ‘omics’ technologies as indicated in thediagram below (taken from ref 2.):As the scheme suggests, metabolomics analyses the biological endpoint of a ‘condition’and this is its key advantage over the other technologies.We are currently engaged in a number of projects in which NMR spectral data recordedfor biofluids –including blood (plasma, sera, erythrocytes), urine and follicular fluid – arebeing analysed using various statistical methods, with the common aim of establishing alink between components of the metabolome and the condition being studied. A briefdescription of some of these projects is provided below.1. Nicholson, J. K.; Lindon, J. C.; Holmes, E., Xenobiotica 1999, 29, (11), 1181-1189.2. A. Di Leo et al Annals of Oncology 2007;18 (Supplement 12):xii8–xii14.

NMR-Based Metabolomic Studies of AtherosclerosisWarren Yabsley 1 , Michael Twigg 2 , Shervanthi Homer-Vanniasinkam 2 and JulieFisher 11 School of Chemistry, University of Leeds, Leeds, UK.2 Leeds Vascular Institute, Leeds General Infirmary, Great George Street, Leeds, LS1 2EX, UK.NMR studies are being conducted on plasma collected from a variety ofpatients taking part in studies of vascular disease. Atherosclerosis, for whichmetabolomic biomarkers will besought, is a vascular inflammatorydisease and is the leading cause ofheart attack and stroke 3 .Atherosclerotic lesions result from anexcessive,inflammatoryfibroproliferativeresponse to variousforms of insult to the endothelium andsmooth muscle of the artery wall 4 , theinitial stages of which can occur inchildhood 5 .Fig.1 Formation of advanced atherosclerotic lesion.Rupture of the fibrous cap leads to thrombosis. 33. Tang, Yang, et al., Local maximal stress hypothesis and computational plaque vulnerability index for atheroscleroticplaque assessment. Ann Biomed Eng, 2005. 33(12): 1789.4. Ross, The pathogenesis of atherosclerosis - a perspective for the 1990s. Nature, 1993. 362(6423): 801.5. Ross, Mechanisms of disease - Atherosclerosis - An inflammatory disease. New England Journal of Medicine, 1999.340(2): 115.NMR-Based Profiling of Ovarian Follicular Fluid and PlasmaCassey McRae 1 , Nic Orsi 2 , Vinay Sharma 3 and Julie Fisher 11 School of Chemistry, University of Leeds, Leeds, UK.2 Leeds Institute of Molecular Medicine (LIMM), Leeds, UK.3 The Assisted Conception Unit at St. James’s Hospital, Leeds, UK.The metabolic profile of women undergoing fertility treatment is beinganalysed by applying high resolution NMR-based metabolomics to follicular fluidand plasma. Female egg cells (oocytes) are produced and grow inside follicles

(Figure 2) in the ovaries before ovulation. Inside the follicle the oocyte issurrounded by a fluid called follicular fluid (FF), which fills the follicular antrum.It has been shown that FF contains substances that are essential insuccessful follicle growth and oocyte fertilisation 2 . Therefore metabolomicprofiling of FF from women whohave been successful orunsuccessful in infertilitytreatment may give rise tobiomarkers that indicate thelikelihood of success of thetreatment. Considering theemotional, health and financialcommitment involved in fertilitytreatment, finding a biomarkerthat would predict the chancesof successful fertilisation isclearly desirable.Fig. 2 Ovarian graafian follicle. 66. Kronenberg, H.M., Melmed, S., et al. ‘Williams Textbook of Endocrinology.’ Philadelphia: Saunders/Elsevier, 2008.________________________________________________________________NMR-based metabolomics in the search for a biomarker of acute rejectionin renal transplantationHayley Fenton 1 , Paul Goldsmith 2 , Niaz Ahmad 2 , Rajendra Prasad 2 and JulieFisher 11 School of Chemistry, University of Leeds, Leeds, UK.2 Department of Organ Transplantation, St James’s University Hospital, Leeds, UK.A Nuclear Magnetic Resonance (NMR)-based metabolomic approach isbeing used to study erythrocyte extracts taken from renal transplant patients withthe aim of identifying possible biomarkersof acute rejection. This project is beingconducted in tandem with Paul Goldsmithwho is carrying out similar analysis of theplasma (see below).Fig. 3 Kidney transplantation 7

Acute rejection occurs due to transplantation into a genetically dissimilarhost. It is one of the key factors determining long-term graft function and survivalin renal patients, being associated with an increasing risk of graft loss 8 . It occursepisodically within the first few months post transplantation and is usuallyaccompanied by an increase in serum creatinine concentration, which is used byclinicians as a diagnostic test of renal function. However this test is non-specificand it is difficult to differentiate acute rejection from delayed graft function(DGF) 9 .For definitive diagnosis a biopsy isrequired, which poses risks to both thepatient and graft and can also lead todelayed detection, allowing the conditionto reach a more advanced state 10 . Earlierdetection ensures treatment can beadministered before substantial damageis caused to the graft. A potentialbiomarker of acute rejection is sought,which may provide an earlier, noninvasivemethod for the diagnosis of acuterejection.7. The New York Times. Health: Kidney Transplant. 2009; Available from:http://www.nytimes.com/slideshow/2007/08/01/health/100087Kidneytransplantseries_5.html.8. McDonald, S., et al., American Journal of Transplantation, 2007. 7(5): p. 1201-1208.9. Serkova, N., et al., Kidney International, 2005. 67(3): p. 1142-1151.10. McLaren, A.J., et al. Annals of Surgery, 2000. 232(1): p. 98-103._______________________________________________________________Metabolomic Identification of Non-invasive Biomarkers for Delayed Graftfunction and Acute Rejection in Solid Organ Transplantation Using 1 H NMRSpectroscopyPaul Goldsmith 1 , Niaz Ahmad 1 , K. Rajendra Prasad 1 and Julie Fisher 21 Department of Organ Transplantation, St James’s University Hospital, Leeds, UK.2 School of Chemistry, University of Leeds, Leeds, UK.Definitive diagnosis of delayed graft function or acute rejection relies oninvasive biopsy of the transplanted organ. Biopsy is not without its risks and

carries with it morbidity and risk to graft. Less invasive tests currently used inclinical practice are not 100% sensitive or specific.Using 1 H NMR spectroscopy, we are investigating the metabolic change ofplasma from renal and liver transplant recipients over several timepoints in orderto fully understand the metabolic changes associated with transplantation.The project aims to define the metabolic profile of patients undergoingrenal or liver transplantation and the changes associated with graft dysfunction orprimary function.________________________________________________________________

Metabolomics investigations into the effects of deoxynivalenol in humansRichard Hopton 1 , Paul Turner 2 and Julie Fisher 11 School of Chemistry, University of Leeds, Leeds, UK.2Molecular Epidemiology Unit, Centre for Epidemiology and Biostatistics, The LIGHTlaboratories, University of Leeds, Leeds, UK.Mycotoxins, such as deoxynivalenol(DON, Figure 4), are produced by fungi andOcontaminate up to 25% of the worlds foodsupply – frequent human exposure to DON is Othrough consumption of everyday commonOH CH 3wheat based foods like bread and biscuits. TheOHeffects of DON exposure on animals are Fig. 4 Structure of DONgastrointestinal in nature; vomiting, feed refusaland immune modulation. However, whilst most species have a DON detoxifyingcapability – thought to be due to gut microflora – humans lack this detoxificationpathway, and DON contaminated cereals has previously been implicated in foodpoisoning incidents in China and India.The focus of this research is to determine biomarkers of exposure of DONand relate these biomarkers to potential health problems. Analysis of both NMRand mass spectrometric data of human urine samples has permitted volunteersto be categorised into high or low DON exposure. Chemometric analysis of NMRdata, using partial least squares discriminant analysis (PLS-DA), has yielded abiomarker of exposure to DON on a small scale study, and has subsequentlybeen validated with the inclusion of extra samples; these results are beingprepared for publication. A larger scale study is now being conducted under theauspices of the Food Standards Agency.________________________________________________________________________H 3 COOHNMR Studies Towards a Biomarker of PreeclampsiaElizabeth Turner 1 , James J. Walker 2 and Julie Fisher 11 School of Chemistry, University of Leeds, Leeds, UK.2 Leeds Institute of Molecular Medicine (LIMM), Leeds, UK.Preeclampsia (PE) is a human pregnancy-specific condition, the cause ofwhich is not yet fully understood, but oxidative stress is thought to beresponsible. As evidence of secreted factors into maternal circulation isemerging, the analysis of blood samples has the potential to reveal the cause

and progression of this disease. 1 H-NMR spectroscopy and chemometrics wereapplied to establish the metabolic profile for PE, with the hope of identifyingbiomarkers of the condition. This permitted a distinction to be made betweenwomen with a normal pregnancy and those with PE, based on the concentrationsof lipids 11 and aromatic amino acids 12 in plasma, as well as imidazole-basedmarkers in erythrocytes. 1 20Whole SpectrumIt has been100-10-20HIGH BMIHYPOTHYROIDISMVIT C & Ehypothesised that theerythrocyte membranecan be damaged byPE, by lipidperoxidation andprotein modification.19 F and 31 P-Dynamic NMR (DNMR) spectroscopy andmatrix diagonalisation have also been applied to investigate this, by measuringthe rate at which erythrocyte transmembrane exchange processes occur. Nosignificant differences were observed between PE and healthy pregnant womenin the outward permeability or efflux rate constant of fluorinated glucoseexchange. These NMR studies as a whole have contributed to our understandingof the pathogenesis of preeclampsia.11. Turner E, Brewster JA, Simpson NAB, Walker JJ, Fisher J. Reproductive Sciences, accepted.12. Turner E, Brewster JA, Simpson NAB, Walker JJ, Fisher J. Hypertension in Pregnancy 2008; 27 (3): 225-235.13. Turner E, Brewster JA, Simpson NAB, Walker JJ, Fisher J. Hypertension in Pregnancy 2007; 26 (3): 329-342.________________________________________________________________