Combining mass spectrometric platforms for lipidome investigation - Application to the characterisation of disruptions in the lipid profile of pig serum upon β agonist treatment

In the last decade, many mass spectrometric fingerprinting methods dedicated to lipidomics have been proposed: either non-targeted approaches, coupled with annotation methods, or targeted strategies, aiming at specifically monitoring a limited number of substances. In a general public health perspective and through a strategy combining non-targeted and targeted lipidomics MS-based approaches, this study aims at identifying disrupted patterns in serum lipidome upon growth promoter treatment in pig and evaluating the relative contributions of the three platforms involved. Pig serum samples collected during an animal experiment involving control and treated animals, whose food had been supplemented with ractopamine, were extracted and characterised using three MS strategies: Non-targeted RP LC-HRMS; the targeted Lipidyzer platform (differential ion mobility associated with shotgun lipidomics) and a homemade LC-HRMS triglyceride platform. The three different platforms showed complementarity insight into lipid characterisation, which, applied to a selected set of samples, enabled highlighting specific lipid profile patterns involving various lipid classes, mainly in relation with cholesterol esters, sphingomyelins, lactosylceramide, phosphatidylcholines and triglycerides. Thanks to the combination of both non-targeted and targeted MS approaches, the exploration of various compartments of the pig serum lipidome could be performed, including commonly characterised lipids (Lipidyzer), triglyceride isomers (Triglyceride platform) -whose accurate analysis was considered an analytical challenge, and unique lipid features (non-targeted LC-HRMS). Thanks to their respective characteristics, the complementarity of the three tools could be demonstrated for public health purposes, with enhanced lipidome coverage, level of characterisation and applicability.