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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
11
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pubmed:dateCreated |
1988-3-2
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pubmed:abstractText |
Lipoprotein secretion by Caco-2 cells, a human intestinal cell line, was studied in cells grown on inserts containing a Millipore filter (0.45 micron), separating secretory products from the apical and basolateral membranes into separate chambers. Under these conditions, as observed by electron microscopy, the cells formed a monolayer of columnar epithelial cells with microvilli on the apical surface and tight junctions between cells. The electrical resistances of the cell monolayers were 250-500 ohms/cm2. Both 14C-labeled lipids and 35S-labeled proteins were used to assess lipoprotein secretion. After a 24-hr incubation with [14C]oleic acid, 60-80% of the secreted triglyceride (TG) was in the basolateral chamber; 40% of the TG was present in the d less than 1.006 g/ml (chylomicron + VLDL) fraction and 50% in the 1.006 less than d less than 1.063 g/ml (LDL) fraction. After a 4-hr incubation with [35S]methionine, apolipoproteins were found to be major secretory products with 75-100% secreted to the basolateral chamber. Apolipoproteins B-100, B-48, E, A-I, A-IV, and C-III were identified by immunoprecipitation. The d less than 1.006 g/ml fraction was found to contain all of the major apolipoproteins, while the LDL fraction contained primarily apoB-100 and apoE; the HDL (1.063 less than d less than 1.21 g/ml) fraction principally contained apoA-I and apoA-IV. Mn-heparin precipitated all of the [35S]methionine-labeled apoB-100 and B-48 and a majority of the other apolipoproteins, and 80% of the [14C]oleic acid-labeled triglyceride, but only 15% of the phospholipid, demonstrating that Caco-2 cells secrete triglyceride-rich lipoproteins containing apoB. Secretion of lipoproteins was dependent on the lipid content of the medium; prior incubation with lipoprotein-depleted serum specifically reduced the secretion of lipoproteins, while addition of both LDL and oleic acid to the medium maintained the level of apoB-100, B-48, and A-IV secretion to that observed in the control cultures.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Apoproteins,
http://linkedlifedata.com/resource/pubmed/chemical/Heparin,
http://linkedlifedata.com/resource/pubmed/chemical/Lipids,
http://linkedlifedata.com/resource/pubmed/chemical/Lipoproteins,
http://linkedlifedata.com/resource/pubmed/chemical/Methionine,
http://linkedlifedata.com/resource/pubmed/chemical/Oleic Acids,
http://linkedlifedata.com/resource/pubmed/chemical/Sulfur Radioisotopes
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pubmed:status |
MEDLINE
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pubmed:month |
Nov
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pubmed:issn |
0022-2275
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
28
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1350-63
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:3430064-Apoproteins,
pubmed-meshheading:3430064-Cell Line,
pubmed-meshheading:3430064-Electric Conductivity,
pubmed-meshheading:3430064-Electrophoresis, Polyacrylamide Gel,
pubmed-meshheading:3430064-Heparin,
pubmed-meshheading:3430064-Humans,
pubmed-meshheading:3430064-Intestines,
pubmed-meshheading:3430064-Lipids,
pubmed-meshheading:3430064-Lipoproteins,
pubmed-meshheading:3430064-Methionine,
pubmed-meshheading:3430064-Microscopy, Electron,
pubmed-meshheading:3430064-Oleic Acids,
pubmed-meshheading:3430064-Precipitin Tests,
pubmed-meshheading:3430064-Sulfur Radioisotopes,
pubmed-meshheading:3430064-Ultracentrifugation
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pubmed:year |
1987
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pubmed:articleTitle |
Polarized secretion of newly synthesized lipoproteins by the Caco-2 human intestinal cell line.
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pubmed:affiliation |
Department of Medicine, New York University School of Medicine, NY 10016.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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