Abstract
The generation and analysis of vascular lesions in appropriate animal models is a cornerstone of research into cardiovascular disease, generating important information on the pathogenesis of lesion formation and the action of novel therapies. Use of atherosclerosis-prone mice, surgical methods of lesion induction, and dietary modification has dramatically improved understanding of the mechanisms that contribute to disease development and the potential of new treatments.Classically, analysis of lesions is performed ex vivo using 2-dimensional histological techniques. This article describes application of optical projection tomography (OPT) to 3-dimensional quantitation of arterial lesions. As this technique is non-destructive, it can be used as an adjunct to standard histological and immunohistochemical analyses.Neointimal lesions were induced by wire-insertion or ligation of the mouse femoral artery whilst atherosclerotic lesions were generated by administration of an atherogenic diet to apoE-deficient mice.Lesions were examined using OPT imaging of autofluorescent emission followed by complementary histological and immunohistochemical analysis. OPT clearly distinguished lesions from the underlying vascular wall. Lesion size was calculated in 2-dimensional sections using planimetry, enabling calculation of lesion volume and maximal cross-sectional area. Data generated using OPT were consistent with measurements obtained using histology, confirming the accuracy of the technique and its potential as a complement (rather than alternative) to traditional methods of analysis.This work demonstrates the potential of OPT for imaging atherosclerotic and neointimal lesions. It provides a rapid, much needed ex vivo technique for the routine 3-dimensional quantification of vascular remodelling.
Highlights
The formation of arterial lesions is central to the high morbidity and mortality associated with cardiovascular disease[1]
Analysis of lesion size and composition has classically depended heavily on ex vivo, 2–dimensional histology
Whole-mount 3-dimensional imaging technology provides a possible solution to this problem but surprisingly few suitable approaches have been described. This may be due predominantly to the size of mouse arteries which are too large for single-photon confocal microscopy but too small for magnetic resonance imaging (MRI)[4] and X-ray computed tomography (CT)[5]
Summary
The formation of arterial lesions is central to the high morbidity and mortality associated with cardiovascular disease[1]. For either imaging mode (transmission or emission), light is focused to a charge-coupled device to allow iterative image capture as the sample rotates (usually 400 images at 0.9° increments) These can be used for calculation of volume by standard tomographic reconstruction methods (such as filtered back-projection (using a cone algorithm) or iterative reconstruction). This video demonstrates our novel application of OPT for rapid, quantifiable and cost-effective 3-dimensional analysis of atherosclerotic and neointimal lesions, as previously described in Kirkby et al.[11]. The technique was shown to be suitable for quantifying lesion size in three commonly used models: (i) femoral artery wire-injury; (ii) femoral artery ligation, and (iii) diet-induced atherosclerosis in apolipoprotein E deficient (apoE-/-) mice
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have