Vascular lipid accumulation, lipoprotein oxidation, and macrophage lipid uptake in hypercholesterolemic zebrafish.
Lipid accumulation in arteries induces vascular inflammation and atherosclerosis, the major cause of heart attack and stroke in humans. Extreme hyperlipidemia induced in mice and rabbits enables modeling many aspects of human atherosclerosis, but microscopic examination of plaques is possible only postmortem. Here we report that feeding adult zebrafish (Danio rerio) a high-cholesterol diet (HCD) resulted in hypercholesterolemia, remarkable lipoprotein oxidation, and fatty streak formation in the arteries. Feeding an HCD supplemented with a fluorescent cholesteryl ester to optically transparent fli1:EGFP zebrafish larvae in which endothelial cells express green fluorescent protein (GFP), and using confocal microscopy enabled monitoring vascular lipid accumulation and the endothelial cell layer disorganization and thickening in a live animal. The HCD feeding also increased leakage of a fluorescent dextran from the blood vessels. Administering ezetimibe significantly diminished the HCD-induced endothelial cell layer thickening and improved its barrier function. Feeding HCD to lyz:DsRed2 larvae in which macrophages and granulocytes express DsRed resulted in the accumulation of fluorescent myeloid cells in the vascular wall. Using a fluorogenic substrate for phospholipase A(2) (PLA(2)), we observed an increased vascular PLA(2) activity in live HCD-fed larvae compared to control larvae. Furthermore, by transplanting genetically modified murine cells into HCD-fed larvae, we demonstrated that toll-like receptor-4 was required for efficient in vivo lipid uptake by macrophages. These results suggest that the novel zebrafish model is suitable for studying temporal characteristics of certain inflammatory processes of early atherogenesis and the in vivo function of vascular cells.
Stoletov
Konstantin
K
Department of Pathology, University of California at San Diego, La Jolla 92093-0682, USA.
Fang
Longhou
L
Choi
Soo-Ho
SH
Hartvigsen
Karsten
K
Hansen
Lotte F
LF
Hall
Chris
C
Pattison
Jennifer
J
Juliano
Joseph
J
Miller
Elizabeth R
ER
Almazan
Felicidad
F
Crosier
Phil
P
Witztum
Joseph L
JL
Klemke
Richard L
RL
Miller
Yury I
YI
D000367:Age Factors; D000375:Aging / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D000924:Anticholesteremic Agents / Q000494:pharmacology; D050197:Atherosclerosis / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D001384:Azetidines / Q000494:pharmacology; D002460:Cell Line; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D000069438:Ezetimibe; D005260:Female; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D006937:Hypercholesterolemia / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D007814:Larva / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects; D008074:Lipoproteins / Q000097:blood / Q000378:metabolism*; D008164:Luminescent Proteins / Q000235:genetics; D008264:Macrophages / Q000378:metabolism* / Q000637:transplantation; D008297:Male; D051379:Mice; D018613:Microscopy, Confocal; D010084:Oxidation-Reduction; D010539:Permeability; D054467:Phospholipases A2 / Q000378:metabolism; D013997:Time Factors; D051197:Toll-Like Receptor 4 / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology / Q000235:genetics / Q000378:metabolism*
D000924:Anticholesteremic Agents; D001384:Azetidines; D002791:Cholesterol, Dietary; D008074:Lipoproteins; D008164:Luminescent Proteins; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; C485184:enhanced green fluorescent protein; C413663:fluorescent protein 583; D049452:Green Fluorescent Proteins; D054467:Phospholipases A2; D000069438:Ezetimibe