Metabolomics is the application of advanced analytical and statistical tools to study changes in levels of endogenous metabolites (produced internally) in cells, tissues and biofluids that result from disease onset, stress, chemical exposure, or environmental change.
Although more commonly used in mammalian systems, metabolomics can also be applied to other organisms such as aquatic species to assess ecological exposures. Metabolomics additionally offers great potential for use in assessing exposure scenarios and human and eco-toxicology.
EPA metabolomics research
EPA metabolomics scientists in Athens, Ga., are using advanced analytical and chemometric techniques (the application of mathematical or statistical methods to chemical data) to gain a better understanding of how exposure events are linked to adverse “whole animal” outcomes, particularly in ecological settings. This involves identifying the relevant biochemical pathways that lead to toxicity that ultimately can be used as markers of chemical exposures. This work involves conducting metabolomics studies on small fish (such as fathead minnows) that serve as model organisms in eco-toxicology research and regulatory testing.
Coupling metabolomics with state-of-the-science methods
Much of EPA’s analytical work in this field is conducted with nuclear magnetic resonance (NMR) spectroscopy, however EPA researchers are also pursuing other analytical techniques —mainly mass spectrometry — for problems that aren’t suited to NMR analysis alone. Further, EPA scientists are exploring new chemometric techniques that are more powerful and better suited for metabolomic application than current techniques.
Exciting challenges remain for using eco-metabolomics in field conditions to conduct biologically-based exposure monitoring in impacted waters to assist environmental regulators, including EPA’s Great Lakes National Program Office, the National Enforcement Investigations Center, regions, and states.
For these applications, caged fish are deployed in areas of chemical impacts and changes in their endogenous metabolites, relative to fish deployed in pristine sites, are related to chemical contaminants in the impacted ecosystem.
Coupling eco-metabolomic studies with other sophisticated methods such as genomics, transcriptomics, ecosystem stoichiometry, community biology and biogeochemistry may generate additional gains in areas of ecological science such as stress responses, species lifestyle, life history variation, population structure, trophic interaction, nutrient cycling, ecological niche and global change.
Technical Contacts: Drew Ekman (contact) and Tim Collette