Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Proteome screening for identification of markers of glucocorticoid exposure

The goal of workpackage 4 was to determine proteins in blood or tissue that are specifically related, either induced or suppressed, to glucocorticoid administration to cattle. For this identified biomarker or set of biomarkers, one or more specific immunoassays were to be developed, validated on samples of treated animals and ringtested by several laboratories.

An innovative approach was developed in which the analysis was not directly targeted towards the minute amounts of glucocorticoids in body fluids, excreta or tissues, but towards the biological effects of glucocorticoids in the body. This enables detection even without knowing which glucocorticoid is administered.

The analysis of the biological effect at the level of the gene expression was initially planned by measurements of proteins (proteomics or proteome analysis). In a later phase the expression of genes by measurements of messenger RNA (mRNA) was also added to the workpackage.

The intended measurements of liver and blood samples with proteomics were not possible. In stead, a U937 macrophage cell system and a L6 myotubes system were used to detect proteins and genes that could be regarded as specific biomarkers.

Several proteins and genes were identified as potentially interesting, some of which were confirmed by mass spectrometry. Within the timeframe available it was not possible to further investigate the selectivity of the biomarkers and the presence in body fluids or tissues. As a consequence, it was not possible to develop one or more immunoassays for the direct detection of the biomarkers in for example blood. Hence, the validation and the ringtest could not be organised.

Nevertheless, the technologies developed have greatly improved the possibilities for the testing the biological effects of pharmacologically active substances in well defined cell systems, the analysis of proteins with proteomics and mass spectrometric techniques, the analysis of genes (mRNA) with DNA arrays (transcriptomics) and multivariate statistics for advanced data evaluation. This generally applicable panel of methods can and will be used for new research projects.

Informations connexes

Reported by

Netherlands Organisation for Applied Scientific Research - TNO
3700 AJ Zeist