Linked Life Data

10769131

Source:http://linkedlifedata.com/resource/pubmed/id/10769131

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
2000-6-1
pubmed:abstractText
Apolipoprotein E (apoE) on model triglyceride-rich particles (TGRP) increases triglyceride (TG) utilization and cholesteryl ester (CE) hydrolysis, independent of its effect on enhancing particle uptake. We questioned whether, under physiological concentrations, endogenously expressed apoE has similar effects on cellular lipid metabolism as compared to exogenous apoE. J774 macrophages, which do not express apoE, were engineered to express endogenous apoE by transfection of human apoE3 cDNA expression constructs (E(+)) or control vectors (E(-)) into the cells. To compare the effects of exogenous apoE and endogenous apoE on TGRP uptake, cells were incubated with or without apoE associated with (3)H-cholesteryl ether-labeled TGRP. Exogenous apoE enhanced TGRP uptake in both E(-) and E(+) cells. E(-) cells displayed significantly higher TGRP uptake than E(+) cells. Sodium chlorate, which inhibits cell proteoglycan synthesis, markedly diminished differences in TGRP uptake between E(-) and E(+) cells, suggesting that endogenous apoE-proteoglycan interaction contributes to differences in uptake between the two cell types. Particle uptake by the LDL receptor, by the LDL receptor related protein, or by scavenger receptors were similar between E(-) and E(+) cells indicating that endogenous apoE expression does not have a general effect on endocytic pathways. Exogenous apoE carried on TGRP stimulated TG utilization and CE hydrolysis in both cell types. However, TG utilization and CE hydrolysis were not affected by endogenous apoE expression. In conclusion, macrophage expression of apoE has very different effects on TGRP metabolism than exogenously supplied apoE. The fluorescence microscopy results in this study showing that exogenous apoE and endogenous apoE were confined in separate cellular compartments support the hypothesis that these differences resulted from distinct intracellular trafficking pathways followed by exogenous apoE bound to TGRP as compared to endogenous cell-expressed apoE.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
39
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4746-54
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:10769131-Apolipoproteins E, pubmed-meshheading:10769131-Biological Transport, pubmed-meshheading:10769131-Cell Line, pubmed-meshheading:10769131-Chlorates, pubmed-meshheading:10769131-Cholesterol Esters, pubmed-meshheading:10769131-Endocytosis, pubmed-meshheading:10769131-Gene Deletion, pubmed-meshheading:10769131-Golgi Apparatus, pubmed-meshheading:10769131-Humans, pubmed-meshheading:10769131-Hydrolysis, pubmed-meshheading:10769131-Lipid Metabolism, pubmed-meshheading:10769131-Lipoproteins, LDL, pubmed-meshheading:10769131-Lysosomes, pubmed-meshheading:10769131-Macrophages, pubmed-meshheading:10769131-Microscopy, Fluorescence, pubmed-meshheading:10769131-Proteoglycans, pubmed-meshheading:10769131-Receptors, LDL, pubmed-meshheading:10769131-Transfection, pubmed-meshheading:10769131-Triglycerides, pubmed-meshheading:10769131-alpha-Macroglobulins
pubmed:year
2000
pubmed:articleTitle
Endogenously expressed apolipoprotein E has different effects on cell lipid metabolism as compared to exogenous apolipoprotein E carried on triglyceride-rich particles.
pubmed:affiliation
Department of Pediatrics, Institute of Human Nutrition, College of Physicians and Surgeons of Columbia University, New York, New York 10032, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't