Metabolomics – A Tool for Grouping of Chemicals and Illustration of Mechanism of Action

By Kasper Skov

19/03-2015 Cocktail Seminar 2 DTU Food, Technical University of Denmark

Agenda

• Introduction

– Metabolism and metabolomics

– Mass spectrometry

– Statistics

• Results

– Influence of Perfluorononanoic acid (PFNA) ± mixture of EDC on rat blood metabolome

• Conclusion

19/03-2015 Cocktail Seminar 3 DTU Food, Technical University of Denmark

Metabolomics is the scientific study of chemical processes involving metabolites.

Specifically, metabolomics is the "systematic study of the unique chemical fingerprints that specific cellular processes leave behind", the study of their small-molecule metabolite profiles.

The metabolome represents the collection of all metabolites in a biological cell, tissue, organ or organism, which are the end products of cellular processes.

Wikipedia

Metabolomics

• Analysis of all (or as many as possible) low molecular weight metabolites in a specific biological compartment. In the present study rat blood.

Metabolism

19/03-2015 Cocktail Seminar 4 DTU Food, Technical University of Denmark

Compounds in the metabolome, examples

Amino acids carbohydrates

cholesterol Fatty acids

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Metabolomics - relation to other omics

• Analysis of the metabolism [omics = analysis of ; metabol = metabolism]

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Mass spectrometry

343.123488

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Analysis one chromatogram from each animal

200

400

600

800

1000

m/z

0 2 4 6 8 10 Time [min]

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Statistics – a tool for identification

Comparison of exposed vs non-exposed animals

Animaldata

-0.4 0.0 0.4 PC 1

-0.50

-0.25

0.00

0.25

0.50

PC 2

Scoreplot

19/03-2015 Cocktail Seminar 9 DTU Food, Technical University of Denmark

Design of rat study

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Metabolomics – workflow

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Results PFNA Experiment

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Low dose effect

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Phospholipids

Cocktail effect?

Or similar composition

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Mechanisms of action for PFNA

• Decreased plasma lipid levels

• Activation of Peroxisome proliferator-activated receptor (PPAR)

• Two possible MoA

– PPAR is activated => increased beta-oxidation, explaining the decreased levels of plasma lipids

– The plasma lipid concentration is lower due to a response to achieve more energy to protect the body

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Metabolomics Conclusion and future perspective

• We identified changes in the metabolism even at low dose exposure

• Study how exogenous compounds effect the body metabolome.

• With a larger database of toxicity studies with metabolomic investigation. Grouping of chemicals which similar mechanism of action based on similar changes in metabolite panels.

19/03-2015 Cocktail Seminar 16 DTU Food, Technical University of Denmark

Thanks to

• The cocktail team.

• Danish Veterinary and Food Administration

• Ministry of Food, Agriculture and Fisheries

19/03-2015 Cocktail Seminar 17 DTU Food, Technical University of Denmark

Questions ?