Oxidized Cholesteryl Esters and Phospholipids in Zebrafish Larvae Fed a High Cholesterol Diet

Abstract

A novel hypercholesterolemic zebrafish model has been developed to study early events of atherogenesis. This model utilizes optically transparent zebrafish larvae, fed a high cholesterol diet (HCD), to monitor processes of vascular inflammation in live animals. Because lipoprotein oxidation is an important factor in the development of atherosclerosis, in this study, we characterized the oxidized lipid milieu in HCD-fed zebrafish larvae. Using liquid chromatography-mass spectrometry, we show that feeding an HCD for only 2 weeks resulted in up to 70-fold increases in specific oxidized cholesteryl esters, identical to those present in human minimally oxidized LDL and in murine atherosclerotic lesions. The levels of oxidized phospholipids,suchas1-palmitoyl-2-oxovaleroyl-sn-glycero-3-phosphocholine, and of various lysophosphatidylcholines were also significantly elevated. Moreover, lipoproteins isolated from homogenates of HCD-fed larvae induced cell spreading as well as ERK1/2, Akt, and JNK phosphorylation in murine macrophages. Removal of apoB-containing lipoproteins from the zebrafish homogenates with an anti-human LDL antibody, as well as reducing lipid hydroperoxides with ebselen, resulted in inhibition of macrophage activation. The TLR4 deficiency in murine macrophages prevented their activation with zebrafish lipoproteins. Using biotinylated homogenates of HCD-fed larvae, we demonstrated that their components bound to murine macrophages, and this binding was effectively competed by minimally oxidized LDL but not by native LDL. These data provide evidence that molecular lipid determinants of proatherogenic macrophage phenotypes are present in large quantities in hypercholesterolemic zebrafish larvae and support the use of the HCD-fed zebrafish as a valuable model to study early events of atherogenesis.

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

“…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].…”

Protective effect of the polarity of macrophages regulated by IL-37 on atherosclerosis

“…M2 cells can inhibit the inflammatory response and facilitate the recovery of tissue injuries via the release of IL-10, arginase, and the scavenger receptor (Spivia et al, 2014). It is interesting to note that the major component of atherosclerotic plaques, oxygenated cholesterol, primarily facilitates the differentiation of M1 cells through activation of the MAP signaling pathway (Fang et al, 2010). All of these studies support a critical role of M1/M2 cell differentiation in the pathogenesis and progression of atherosclerosis.…”