Recent Publications

Identification of key lipids critical for platelet activation by comprehensive analysis of the platelet lipidome

Abstract

Platelet integrity and function critically depend on lipid composition. However, the lipid inventory in platelets was hitherto not quantified. Here, we examined the lipidome of murine platelets using lipid-category tailored protocols on a quantitative lipidomics platform. We could show that the platelet lipidome comprises almost 400 lipid species and covers a concentration range of seven orders of magnitude. A systematic comparison of the lipidomics network in resting and activated murine platelets, validated in human platelets, revealed that less than 20% of the platelet lipidome is changed upon activation, involving mainly lipids containing arachidonic acid. Sphingomyelin phosphodiesterase-1 (Smpd1) deficiency resulted in a very specific modulation of the platelet lipidome with an order of magnitude up-regulation of lyso-sphingomyelin (SPC), and subsequent modification of platelet activation and thrombus formation. In conclusion, this first comprehensive quantitative lipidomic analysis of platelets sheds light on novel mechanisms important for platelet function, and has therefore the potential to open novel diagnostic and therapeutic opportunities.

Peng, B. et al. Identification of key lipids critical for platelet activation by comprehensive analysis of the platelet lipidome. Blood (2018)
doi:10.1182/blood-2017-12-822890

Supplementary Material: Bioinformatics Scripts for Visualization and Network Analysis

Software-aided quality control of parallel reaction monitoring based quantitation of lipid mediators

Abstract

We characterized the performance of a micro-flow LC-ESI-MS2 approach to analyze lipid mediators (LMs) and polyunsaturated fatty acids (PUFA) that was optimized for SPE free lipid extraction. Tandem mass spectrometry was exclusively performed in parallel reaction monitoring (PRM) mode using TOF and Orbitrap analyzers. This acquisition strategy allowed in addition to quantitation by specific quantifier ions to perform spectrum comparisons using full MS2 spectra information of the analyte. Consequently, we developed a dedicated software SpeCS that allows to 1) process raw peak lists, 2) generate customized spectral libraries, 3) test specificity of quantifier ions and 4) perform spectrum comparisons. The dedicated scoring algorithm is based on signal matching and Spearman's rank correlation of intensities of matched signal. The algorithm was evaluated in respect of its specificity to distinguish structural related LMs on both instrument platforms. We show how high resolution mass spectrometry is beneficial to distinguish co-eluted LM isomers and provide a generalized quality control procedure for PRM. The applicability of the approach was evaluated analyzing the lipid mediator response during M. tuberculosis infection in the mouse lung.

Wutkowski, A. et al. Software-aided quality control of parallel reaction monitoring based quantitation of lipid mediators. Analytica Chimica Acta (2018). doi:10.1016/j.aca.2018.01.044

Shotgun Lipidomics Approach for Clinical Samples

Abstract

Shotgun lipidomics offers fast and reproducible identification and quantification of lipids in clinical samples. Lipid extraction procedures based on the methyl tert-butyl protocol are well established for performing shotgun lipidomics in biomedical research. Here, we describe a shotgun lipidomics workflow that is well suited for the analysis of clinical samples such as tissue samples, blood plasma, and peripheral blood mononuclear cells.

Eggers, L. F. & Schwudke, D. Shotgun Lipidomics Approach for Clinical Samples. in Clinical Metabolomics: Methods and Protocols (ed. Giera, M.) 163–174 (Springer New York, 2018). doi:10.1007/978-1-4939-7592-1_12

Lipidomes of lung cancer and tumour-free lung tissues reveal distinct molecular signatures for cancer differentiation, age, inflammation, and pulmonary emphysema

Abstract

Little is known about the human lung lipidome, its variability in different physiological states, its alterations during carcinogenesis and the development of pulmonary emphysema. We investigated how health status might be mirrored in the lung lipidome. Tissues were sampled for both lipidomic and histological analysis. Using a screening approach, we characterised lipidomes of lung cancer tissues and corresponding tumour-free alveolar tissues. We quantified 311 lipids from 11 classes in 43 tissue samples from 26 patients. Tumour tissues exhibited elevated levels of triacylglycerols and cholesteryl esters, as well as a significantly lower abundance of phosphatidylglycerols, which are typical lung surfactant components. Adenocarcinomas and squamous cell carcinomas were distinguished with high specificity based on lipid panels. Lipidomes of tumour biopsy samples showed clear changes depending on their histology and, in particular, their proportion of active tumour cells and stroma. Partial least squares regression showed correlations between lipid profiles of tumour-free alveolar tissues and the degree of emphysema, inflammation status, and the age of patients. Unsaturated long-chain phosphatidylserines and phosphatidylinositols showed a positive correlation with a worsened emphysema status and ageing. This work provides a resource for the human lung lipidome and a systematic data analysis strategy to link clinical characteristics and histology.

Eggers, L. F. et al. Lipidomes of lung cancer and tumour-free lung tissues reveal distinct molecular signatures for cancer differentiation, age, inflammation, and pulmonary emphysema. Scientific Reports 7, 11087 (2017).

l.isas
l.mpi
fz borstel
BioInfraProt symbol