In vivo visualization and attenuation of oxidized lipid accumulation in hypercholesterolemic zebrafish

Abstract

Oxidative modification of LDL is an early pathological event in the development of atherosclerosis. Oxidation events such as malondialdehyde (MDA) formation may produce specific, immunogenic epitopes. Indeed, antibodies to MDA-derived epitopes are widely used in atherosclerosis research and have been demonstrated to enable cardiovascular imaging. In this study, we engineered a transgenic zebrafish with temperature-inducible expression of an EGFP-labeled single-chain human monoclonal antibody, IK17, which binds to MDA-LDL, and used optically transparent zebrafish larvae for imaging studies. IntroductionCholesterol-fed zebrafish represent a novel animal model in which to study the early events involved in vascular lipid accumulation and lipoprotein oxidation (1, 2). This zebrafish model has several unique advantages. The optical transparency of zebrafish larvae enables high-resolution monitoring of vascular pathology in live animals. Colony maintenance is cost-effective, and many embryos can be produced from a single mating. Further, it is relatively easy to establish new transgenic zebrafish lines harboring fluorescent proteins. Importantly, our recent work established that feeding zebrafish a high-cholesterol diet (HCD) resulted in hypercholesterolemia, vascular lipid accumulation, myeloid cell recruitment, and other pathological processes characteristic of early atherogenesis in mammals (1). HCD-fed zebrafish had remarkably high levels of oxidized lipoproteins and specific oxidized phospholipid and cholesteryl ester moieties as measured by binding of oxidation-specific antibodies and by mass spectrometry (1, 2). These observations suggest that there is accelerated lipid oxidation in HCD-fed zebrafish.Oxidative modification of LDL is widely believed to drive the initial formation and progression of atherosclerotic lesions in humans

Disruption of ldlr causes increased LDL-c and vascular lipid accumulation in a zebrafish model of hypercholesterolemia

“…Larvae were imaged at 20× magnifi cation using an Olympus IX50 epifl uorescent inverted microscope and cellSens Dimension software. The total number of BODIPY 576/589 C11-positive plaques was quantifi ed in a 438.6 × 330.2 m window along the caudal vein for a minimum of 25 larvae per MO per diet, as per published protocols ( 35,42 ).…”

“…Previous reports have demonstrated that zebrafish larvae become hypercholesteremic upon treatment with HCD, exhibiting increased total cholesterol and vascular plaques after 10 days of treatment ( 35,42,43 ). It is unknown, however, if hypercholesteremia in zebrafi sh can result from perturbation of gene expression.…”

Choroidal Vessel Wall: Hypercholesterolaemia-Induced Dysfunction and Potential Role of Statins

“…Cholesterol-fed zebra fish represent a novel animal model in which to study the early events involved in vascular lipid accumulation and lipoprotein oxidation [114,115]. Feeding zebra fish a high-cholesterol diet results in hypercholesterolaemia, vascular lipid accumulation, myeloid cell recruitment, and other pathological processes characteristic of early atherogenesis in mammals [113].…”

AIBP: A Novel Molecule at the Interface of Cholesterol Transport, Angiogenesis, and Atherosclerosis

“…Feeding transgenic zebrafish larvae an HCD for 2 weeks also resulted in oxidation-specific epitopes (OSE) accumulation and vascular inflammation, which increase vascular leakage and macrophage recruitment. 33 We created a transgenic zebrafish with conditional expression of EGFP-tagged single chain monoclonal antibody IK17, which targets malondialdehydemodified epitopes, to monitor the spatiotemporal accumulation of OSE. Furthermore, the expression of IK17-EGFP reduced vascular lipid accumulation.…”

“…Furthermore, the expression of IK17-EGFP reduced vascular lipid accumulation. 33 Thus, from a pathogenesis point of view, the initial events of atherogenesis are conserved between zebrafish and humans.…”