Abstract 9992: Urine Proteome Analysis Allows Establishment of Polypeptide Patterns non-Invasively Reflecting Drug-Mediated Regression of Atherosclerosis in ApoE-/--Mice

Background: Recently, non-invasive urine proteome analysis established a multimarker proteome approach towards non-invasive detection of atherosclerosis in an ApoE-/--mouse model, and relevance of this proteome pattern was also confirmed in human atherosclerosis. Urine was used since it lacks peptidase activity, which is found in blood and could falsify proteome analysis. Additionally, non-invasive monitoring of anti-atherosclerotic therapy with statins is of high clinical interest, and could be an important tool for guiding medical therapy. We therefore aimed to identify urinary polypeptides reflecting statin therapy in the ApoE-/--mouse model. Methods and Results: Urine of ApoE-/--mice either on high fat diet (HFD) or chow diet (CD) was collected over 15 weeks; each group was divided into subgroups with or without statin therapy applied by oral gavaging (HFD+S and HFD-S). Capillary electrophoresis mass spectrometry (CE-MS) of urine samples identified 5 polypeptides specifically reflecting statin treatment, resulting in a shift towards a more “healthy” polypeptide pattern until week 12. Sequencing of the discovered polypeptides identified fragments of α1-antitrypsin, EGF, kidney androgen regulated protein (KAP) and napsin. In histology, plaque size was significantly reduced by statin treatment, and presence of marker proteins in atherosclerotic plaques was confirmed by immunohistochemistry. Furthermore, urinary excretion levels of α1-antitrypsin fragments significantly correlated with intraplaque α1-antitrypsin content, mirroring plaque protein expression in the urine proteome. Conclusions: Urine proteome analysis allows discovery of novel biomarkers for the non-invasive monitoring of an anti-atherosclerotic therapy with statins in an ApoE-/--mouse model. The established multimarker proteome pattern reflects regression of plaque size in histology, and marker excretion levels also correlate with their expression in immunohistochemistry. This approach allows monitoring of atherosclerosis progression and statin treatment in mice, and thus promises to be an important and clinically relevant tool for monitoring and guiding of established but even more so of novel developments of anti-atherosclerotic drugs.