To clarify the mechanism of smooth muscle cell (SMC)-derived foam cell formation, we investigated beta-very low density lipoprotein (beta-VLDL) cholesterol metabolism in vascular medial SMCs (M-SMCs) from normal rabbits compared with intimal SMCs (I-SMCs) from normal rabbits fed a high-cholesterol diet and LDL receptor-deficient rabbits. For both types of I-SMCs, uptake of [3H]cholesteryl oleate labeled beta-VLDL increased 1.6 times and release of [3H]cholesterol decreased 40% compared with M-SMCs. M-SMCs took up part of the beta-VLDL through the LDL receptor but I-SMCs did not. mRNAs for the VLDL receptor and the LDL receptor relative with 11 ligand binding repeats were expressed at similar levels in all SMCs. M-SMCs expressed more LDL receptor-related protein than I-SMCs. Ligand blotting analysis revealed greater 125I-beta-VLDL binding to a 700-kDa protein in I-SMCs compared with M-SMCs. I-SMCs had higher activities of acid cholesterol esterase and acyl-CoA:cholesterol acyltransferase, and lower activity of neutral cholesterol esterase than M-SMCs in both the absence and the presence of beta-VLDL. These results indicate that I-SMCs accumulate more cholesteryl ester than M-SMCs by taking up more beta-VLDL and by effluxing less cholesterol.
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http://dx.doi.org/10.1016/s1388-1981(02)00305-0 | DOI Listing |
Front Cardiovasc Med
July 2024
Guangdong Province Key Laboratory, Southern China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen, China.
Introduction: Apolipoprotein E (apoE) acts as a binding molecule for both the low-density lipoprotein receptor and the lipoprotein receptor-related protein and this function is essential for facilitating the hepatocyte uptake of lipoproteins containing apoB. The absence of apoE leads to increased atherogenicity in both humans and mice, although the precise molecular mechanisms remain incompletely understood.
Objectives: This study aimed to investigate the susceptibility of apoE knockout (KO) rabbits, in comparison with wild-type (WT) rabbits, to diet-induced hyperlipidemia and atherosclerosis.
Int J Mol Sci
November 2018
Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou 225001, China.
Rabbits (Oryctolagus cuniculus) are one of the most widely used animal models for the study of human lipid metabolism and atherosclerosis because they are more sensitive to a cholesterol diet than other experimental animals such as rodents. Currently, two hypercholesterolemic rabbit models are frequently used for atherosclerosis studies. One is a cholesterol-fed wild-type rabbit and the other is the Watanabe heritable hyperlipidemic (WHHL) rabbit, which is genetically deficient in low density lipoprotein (LDL) receptor function.
View Article and Find Full Text PDFRen Fail
November 2018
a Department of Clinical Pharmacy, Graduate School of Pharmaceutical Sciences , Chiba University, Chiba , Japan.
Introduction: Dyslipidemia is one of the onset and risk factors of chronic kidney disease and renal function drop is seen in lipoprotein abnormal animal models. However, the detailed molecular mechanism of renal lipotoxicity has not been clarified. Therefore, the present study aimed to investigate the influence of cholesterol overload using mouse kidney tissue and kidney-derived cultured cells.
View Article and Find Full Text PDFLipids Health Dis
January 2014
Laboratory of Nutrition Chemistry, Division of Bioresource and Bioenvironmental Sciences, Graduate School, Kyushu University, 6-10-1 hakozaki, higashi-ku, Fukuoka 812-8581, Japan.
Background: Exogenously hypercholesterolemic (ExHC) rats develop hypercholesterolemia and low hepatic triacylglycerol (TAG) levels when dietary cholesterol is loaded. The responsible gene Smek2 was identified via linkage analysis using the original strain Sprague-Dawley (SD) rats. In this study, we compared SD and ExHC rats to investigate a relationship between hypercholesterolemia and the low hepatic TAG levels observed in ExHC rats.
View Article and Find Full Text PDFFEBS J
March 2014
Biocomputation and Complex Systems Physics Institute (BIFI). BIFI-Instituto de Química Física Rocasolano (Consejo Superior de Investigaciones Científicas) Joint Unit, Universidad de Zaragoza, Spain; Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Spain.
The molecular mechanism of lipoprotein binding by the low-density lipoprotein (LDL) receptor (LDLR) is poorly understood, one reason being that structures of lipoprotein-receptor complexes are not available. LDLR uses calcium-binding repeats (LRs) to interact with apolipoprotein B and apolipoprotein E (ApoB and ApoE). We have used NMR and SPR to characterize the complexes formed by LR5 and three peptides encompassing the putative binding regions of ApoB (site A and site B) and ApoE.
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