Session WOC. There are 6 abstracts in this session.



Session: *Omics 1, time: 11:00-11:20

NMR-Based Metabolic Profiling of Three Mouse Models of Acute Kidney Injury


Tafadzwa Chihanga1; Shenyuan Xu1; Qing Ma2; Prasad Devarajan2; Steven Standage2; Michael Kennedy1
1Miami University, Oxford, OH; 2Cincinnati Children's Hospital Medical Center, Cincinnati, OH
NMR-based metabolic profiling has been used to investigate three different mouse models of acute kidney injury (AKI): ischemia reperfusion injury (IRI), hypoxia, and sepsis. NMR-based metabolic profiling analyses were supported by commonly used clinical assays of serum creatinine and urinary neutrophil gelatinase-associated lipocalin (NGAL) levels, in addition to kidney histological and immunohistochemical analyses, and, in the case of IRI, scanning and transmission electron microscopy evaluation of damage to glomeruli and proximal and distal tubules. Distinct NMR signatures were detected for IRI, caused by acute loss of proximal tubule brush borders and distal tubule epithelial mitochondria, and for hypoxia, caused acute metabolic suppression. The sepsis model is ongoing and the results will be presented at the meeting.

Session: *Omics 1, time: 11:20-11:40

A Tale of Two Sugars: 13C NMR Study of Glucose and Fructose Metabolism in Glioblastoma Cells


Fatemeh Khashami; Christopher Parish; Brianna Royer; David Clark; Qing Wang; Lloyd Lumata
The University of Texas at Dallas, Richardson, TX
Increased dietary consumption of sugar has been implicated in a number of clinical pathologies, including obesity and other metabolic diseases. High fructose corn syrup, a sugar mixture of about 40% glucose and 60% fructose, is a ubiquitous sweetening additive in a number of drinks and food.1 In this study, we have investigated the metabolism of these two types of sugar in glioblastoma cells, specifically the aggressive SfXL cell line. The main finding of this preliminary work is that, despite the same caloric content of these two sugars, fructose and glucose metabolized quite differently in brain cancer cells. 
 

Session: *Omics 1, time: 11:40-12:00

Automated Analysis for Multiplet Identification from Ultra-High Resolution 2D-13C, 1H -HSQC NMR Spectra   


Laura Ferrante
University of Birmingham, Birmingham, United Kingdom
NMR-based stable isotope resolved metabolism analysis is a very powerful tool. To derive meaningful information, signal line shapes from high-resolution 2D-1H,13C-HSQC NMR are quantitatively analysed. However, metabolites identification and multiplet quantification can be very challenging as for example chemical shift changes due to pH changes. Here we present a data-driven, computational approach to automate the analysis of these signals, which is currently a bottleneck in the analysis workflow as data is usually analysed manually. This requires a large degree of expertise from the user, and can lead to a biased signal analysis, which will have a huge impact downstream, where the NMR multiplet data is combined with mass spectrometry (MS) data to derive model-free isotopomer distributions for the metabolites analysed.
 

Session: *Omics 1, time: 12:00-12:20

Development of a Caenorhabditis elegansReference Material for Long-Term Metabolomics Quality Control and Unknown Compound Identification


Goncalo Gouveia1; David Blum1; Emerson Ferreira Queiroz2; Jean-Luc Wolfender2; Lauren McIntyre3; Arthur Edison1
1University of Georgia, Athens, GA; 2University of Geneva, Geneva, Switzerland; 3University of Florida, Gainesville, FL
A critical component for reproducibility in metabolomics is biological reference material that is stable over time, and this study shows how to make and characterize a biological reference material that is stable over many years.To generate this reference material, we utilize a moving average. Individual batches are combined to generate a reference pool that is averaged over batches. For each iteration one batch is added and another removed, which results in most of the batches used in the mixture staying constant. Multiple batches of E. coli(food) and C. elegans are grown in bio-reactors under strictly controlled conditions. Multiple aliquots are constructed from each batch, and each aliquot is characterized by NMR and population measurements.
 

Session: *Omics 1, time: 12:20-12:40

Isotopomic 13C-NMR for Characterization of complex mixtures


Serge Akoka1; Ghina Hajjar2; Noelle Merchak2; Virginie Silvestre1; Toufic Rizk2; Gerald Remaud1; Joseph Bejjani2
1CEISAM, UMR 6230, CNRS/Université de Nantes, Nantes, France; 2Laboratory of Metrology and Isotopic Fractionation, Beirut, Lebanon
Characterization of complex mixtures by NMR can be obtained by the determination of the metabolic profile but also by the determination of the isotopic profile of major components. We show that for the characterization of triglycerides, the 13C-isotopomics approach (metabolomic and isotopic profiles obtained simultaneously) presents many advantages: no need to prior chemical manipulations; determination of the positional distribution of major fatty acids on the glycerol backbone; and measurement of the relative position-specific isotopic 13C content at different sites. Furthermore, all these information are obtained from the same spectrum in only 8 min. This method have been compared with proton profiling and gas chromatography. Its higher efficiency is explained by a significant contribution of variables only obtained by this technique.

Session: *Omics 1, time: 12:40-1:00

Segmented Flow Strategies for Interfacing Microflow NMR with LC-MS to Identify the Volume and Mass-limited Metabolites and Lipids   


Rohit Mahar; Jiajun Lei; Timothy Garrett; Richard Yost; Matthew Merritt
University of Florida, Gainesville, Florida
Lipids are structurally diverse and contain all isomers such as cis, trans and sn. While mass spectrometry is highly sensitive, it has very limited ability to distinguish between isomers. Two pairs of phosphatidylcholine (PC) isomers e.g. cis/trans isomers - PC(16:1/16:1) Δ9 cis and PC(16:1/16:1) Δ9 trans and positional isomers - PC(18:1/18:1) Δ9 cis and PC(18:1/18:1) Δ6 cis, were used to evaluate the potential of microcoil NMR for rapidly determining lipid double bond conformations. The limit of detection (LOD) of Microflow NMR (Protasis) was measured using the diacylglycerol DG(22:1/22:1) sn 1,3 and found to be in the nmol range. Hence, the 1H NMR spectra produce from ~2 µl of Microcoil active volume, makes it advantageous for volume- or mass-limited samples.