Frontiers in Lipidomics – The Food, Nutrition and Health Connection
The Transition From Lipid Analysis to Lipidomics
Joseph Dixon, Ph.D., Dept. of Nutritional Sciences, Rutgers University
This talk will provide a platform for the following presentations by the distinguished guest speakers. The transition from lipid analysis to lipidomics will be the main focus of the talk. Structures of triacylgly-cerols and phosphatidylcholines will be presented so that all attendees are on an equivalent footing concerning the role of fatty acids in dictating the relative molecular masses of most lipids. Each lipid class requires unique ionization conditions and the hurdles this presents will be addressed. There will be a short discussion of triple quadrupole mass spectrometers. The current lipidomics approach used in the core facility, which we call Class Based Lipidomics, will be discussed. Finally, the six areas in cell biology/health where lipidomics research will have an important and immediate impact will be presented.
Joseph Dixon received M.S. and Ph.D. degrees from the University of Wisconsin-Madison. In 1989 he went to Columbia University to work with Dr. Henry N. Ginsberg on the intracellular regulation of apolipoprotein B synthesis and secretion in hepatocytes. In 2004, Dr. Dixon moved to Rutgers University, New Jersey, which has a strong lipid research group (Rutgers Center for Lipid Research; http://rclr.rutgers.edu). In 2006, Dr. Dixon's prior analytical chemistry experience with complex lipids led him to begin using mass spectrometry to perform lipidomics research. Dr. Dixon's main research interest continues to center around the regulation of the hepatic secretion of VLDL and the control of blood lipids. He also performs research in lipoprotein metabolism, lipid metabolism in diabetes and obesity, and the role of lipids in the development of coronary arteriosclerosis. Recently, Dr. Dixon has been involved in projects to produce biofuels from plant and algae triglycerides.
The Macrophage and Plasma Lipidomes in Health, Nutrition, and Disease
Edward Dennis, Ph.D., Dept. of Chemistry and Biochemistry and Dept. of Pharmacology, University of California, San Diego
The 21st century has already seen the development of comprehensive proteomics analyses, but the emerging evolution is to metabolomics, the identification and quantitation of all of the molecular constituents of the cell. By far, the largest number of distinct molecular species in cellular metabolism lies in the fats (or lipids). We have applied novel liquid chromatographic-mass spectrometric based techniques termed "CLASS" in an overall omics analysis of immunologically-activated macrophages integrating transcriptomics, proteomics, and metabolomics of lipid metabolites. As part of the LIPID MAPS Consortium (www.lipidmaps.org), our laboratory has developed a robust and comprehensive approach to the analysis of hundreds of fatty acids, acylethanolamines and inflammatory eicosanoids, and their numerous metabolites. We will discuss the application of lipidomic analysis to characterize cellular lipid signaling of Toll-like (TLR) and purinergic receptors and their "synergy" in endotoxin stimulated macrophages as models for inflammation and infection. New results comparing various primary macrophages and analysis of the fluxes of metabolites as well as "directed proteomics" of the system will be presented. Also lipidomic analysis of cells supplemented with small amounts of the omega-3 fatty acids eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) provides information on the overall effects of EPA and DHA on the inflammatory eicosadome. Human plasma has also been profiled to quantify almost six hundred distinct lipid molecular species present across all mammalian lipid categories; the implications for the future of clinical medicine and the understanding of the mechanisms of disease will be discussed.
Edward A. Dennis is Distinguished Professor of Chemistry and Biochemistry and of Pharmacology in the School of Medicine at the University of California at San Diego (UCSD). He received his BA from Yale University in 1963 and a Ph.D. from Harvard University in 1967. Dr. Dennis' career research focus has been on the mechanism of the enzyme phospholipase A2, signal transduction, inflammation, lipid metabolism, oxidized lipids, eicosanoids, and developing the lipidomics field. He has authored over 340 original research publications, patented 15 inventions, and edited 13 books. He is currently Editor-in-Chief of the Journal of Lipid Research and Director of the LIPID MAPS Consortium. Dr. Denniswas named an inaugural Fellow of the American Association for the Advancement of Science (AAAS) in 1984.
Targeted Lipidomic Profiling: A Powerful Nutritional Phenotyping Tool
John Newman, Ph.D., USDA/ARS, Western Human Nutrition Research Center and Dept. of Nutrition, University of California, Davis
Nutritional status has broad impacts on health and wellness, and is routinely assessed using a minimum set of clinical measures. Shifting nutritional status assessments to an omics-oriented quantitative nutritional phenotyping approach will provide greater insights into the metabolic consequences of nutritional states and variability in responses to nutritional maintenance/intervention. Moreover, such efforts will provide opportunities to identify discrete nutritional phenotypes within the population. Targeted lipidomics provide broad metabolic and physiologic insights, and will be an important aspect of nutritional phenotyping. Using examples from omega-3 fatty acid feeding studies, the utility of a quantitative lipidomic approach to define basal responses and inter-individual variability in response to treatment will be demonstrated.
John Newman is a Research Chemist at the USDA/ARS Western Human Nutrition Research Center and holds an Adjunct Associate Professorship with the University of California, in Davis CA. He obtained a baccalaureate degree in biochemistry and molecular biology from the University of California, Santa Cruz in 1991, and a Ph.D. in pharmacology and toxicology from the University of California, Davis in 2002. Since joining the USDA, Dr. Newman's research group has continued to expand and enhance analytical tools for targeted metabolic profiling. Current protocols allow the isolation and quantification of ~150 oxylipins, endocannabinoids, and fatty acids, and expansions continue. These tools are being used to evaluate nutritional responses to dietary lipid interventions with an eye toward the use of quantitative metabolomics as a phenotyping tool in the context of human nutrition.
Unbiased analysis of biological samples for lipids and small molecule metabolites
Serhiy Hnatyshyn, Ph.D., Bristol-Myers Squibb
High resolution chromatographic separation coupled with accurately measured mass spectroscopic detection (LC-MS) provides a practical way to begin to dissect the extreme complexity of biological samples. LC-MS enables the detection of a wide variety of small molecules including lipids and facilitates a quantitative evaluation over a wide range of concentrations while remaining amendable to high throughput and automation. Each sample subjected for an accurate mass LC-MS analysis generates a massive amount of information, with each data set usually exceeding one million signal peaks. Converting the collected signals into meaningful data (e.g. tables of annotated metabolites) requires automation. Automated data analysis includes spectral interpretation, alignment and statistical comparison across many samples. This presentation discusses recent advances in the automation of metabolomics data analysis on high resolution LC-MS platforms. The approach is illustrated through examples of detection and quantitation of lipids and small molecules in biological samples.
Dr. Serhiy Hnatyshyn is currently a Senior Research Investigator II at Bristol-Myers Squibb Co. He holds a Ph.D. in Physical Chemistry from Ivan Franko National University of L'viv, L'viv Ukraine, and a Ph.D. in Environmental Sciences from Tennessee Technological University, Cookeville, TN, USA. In addition to his 10+ years at BMS, Dr. Hnatyshyn has several years of experience in bioanalytical chemistry, chemometrics, bioinformatics and software development. His current role is automation, logistics and data analysis in the Applied and Investigational Metabolomics interdisciplinary team at BMS.
What's On the Horizon for Lipidomics
Paul Baker, Ph.D., Lipid Applications Specialist, ABSCIEX
The field of lipid biochemistry has exploded in the last 10 years, primarily as a consequence to the development and availability of electrospray ionization mass spectrometry. As a means of describing the potential future of lipid analysis, specific examples and workflows of targeted and global lipidomics will be presented, including: a) the use of chemical probes and targeted mass spectrometric experiments as a means to discover novel, bioactive lipid mediators such as nitrated lipids; and b) the use of accurate mass MS technology for rapid global lipidomic analysis. The continued support of and advances in lipidomics likely lies in a combination of both targeted and global approaches.
Paul Baker received his Ph.D. in Biochemistry from Wake Forest University School of Medicine, where he began his training in lipids with the study of the metabolism and signaling actions of ether-linked lipid mediators. He did his post-doctoral work with Bruce Freeman at the University of Alabama at Birmingham where he led the discovery of a novel class of anti-inflammatory lipid mediators—nitrated lipids. He continued his work on nitrated lipids as an assistant professor at the University of Pittsburgh School of Medicine until June of 2011 when he joined ABSCIEX as an applications specialist in the field of lipids.