Abstract 15282: Three-Dimensional Network of Lipid Crystals and Vaso Vasorum Based on Coherent Anti-Stokes Raman Spectroscopy Imaging
Increased neovascularization in vasa vasorum (VV) is identified as one of the common features of plaque vulnerability due to the intraplaque hemorrhage. Although developed intraplaque hemorrhage has been regarded as a source of free cholesterol, studies directly linking VV to free cholesterol in 3-dimensional (3D) are lacking. The aim of this study was to investigate the development of 3D network of lipid crystals and VV using coherent anti-Stokes Raman scattering (CARS) microscopy which can monitor the contrast of molecular vibrations. We previously reported a label-free characterization of atherosclerotic lipids by CARS. In this study, we further developed a 3D imaging of the lipids in whole vessels without dissections based on partial carotid ligation. Since partially ligated carotid artery could induce low and oscillatory shear stresses leading to accelerated progression of atherosclerosis, atherosclerotic carotid arteries of apolipoprotein E were suitable for 3D imaging. Whole mount immunostaining was also performed for validation of immune cells. To investigate the development of VV and lipid core, a time-course experiment was conducted from 1 – 4 weeks of high fat diet feeding after partial ligation. At 1 week, foam cells were imaged in intima by CARS. At 4 weeks corresponding to advanced stage, lipid core was label-freely imaged in deep intima with appearance of lipid crystals. We found the development of VV volumetrically wrapping around lipid core. Interestingly, CD1a positive dendritic cells were found in the bifurcation region of the VV. Also, 3D CARS imaging revealed the micro-extensions of lipid core traversing into media. In conclusion, the 3D network of VV and lipid core was demonstrated by CARS and whole mount immunostaining. The association of inflammation through VV was further demonstrated. This CARS and partial carotid ligation integrated platform can provide a new perspective to the assessment of vulnerable plaques.
- © 2010 by American Heart Association, Inc.