Imaging of the biomarkers of atherosclerotic alternations in murine brain – IR and Raman studies

In this work, taking advantages of complementary IR and Raman spectroscopies combined with chemometric analysis we studied the biochemical composition of the grey (GM) and white matter (WM), the general lipid fraction as well as differentiation of cholesterol and its esters for both, control (C57BL/6J) and ApoE/LDLR / ‒ ‒ mice brain tissue with advanced atherosclerosis. The IR and RS results allowed us to calculate that the lipid/protein ratio for atherosclerotic tissue increased by around 27% and 44% over control for GM and WM, respectively. Raman microimaging allowed for spatial differentiation between crystalline cholesterol from other lipids, while IR results suggest an increase in the cholesterol fraction of atherosclerotic white matter and a lack of (or only minor) change in the content of esters (including cholesterol esters and triglycerides). For grey matter, no significant increase in cholesterol was visible; however, increased triglyceride and/or cholesterol ester content was observed.