Linked Life Data

7749882

Source:http://linkedlifedata.com/resource/pubmed/id/7749882

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1995-6-20
pubmed:abstractText
To further elucidate the cellular mechanisms leading to HDL deficiency in Tangier disease, HDL-mediated cholesterol efflux was studied in cultured skin fibroblasts from Tangier patients. Both Tangier and control fibroblasts show specific saturable binding of HDL3 to the cell membrane (Bmax = 70 and 52 ng/mg protein, respectively; Kd = 8.8 and 10.6 micrograms/mL, respectively). There was no appreciable uptake of HDL3 by Tangier and control fibroblasts, indicating that cholesterol efflux from fibroblasts occurs at the cell membrane. When cellular cholesterol was labeled to equilibrium by [14C]cholesterol incubation for 48 hours at 37 degrees C, HDL3-mediated cholesterol efflux from Tangier fibroblasts was only 50% of control fibroblasts. To define this abnormality in HDL3-mediated cholesterol efflux more precisely, several additional experiments were performed. First, membrane desorption of cholesterol was determined after cell membranes were labeled with [14C]cholesterol for 3 hours at 15 degrees C. With this labeling protocol, there was no difference in HDL3-mediated cholesterol efflux between control and Tangier fibroblasts. Second, efflux of newly synthesized sterols was determined after incorporation of the precursor [14C]mevalonolactone. Under these conditions, specific HDL3-mediated efflux of sterols was almost absent in Tangier fibroblasts. Third, cells were labeled by incubation with reconstituted [3H]cholesteryl-linoleate-LDL. Efflux of LDL-derived cholesterol was only slightly reduced for the first 4 hours of incubation. After 12 hours, there was no difference between control and Tangier cells. The combined data indicate that the reduced efflux of cholesterol from Tangier fibroblasts observed after homogeneous labeling is due to severely reduced efflux of newly synthesized sterol.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1079-5642
pubmed:author
pubmed:issnType
Print
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
683-90
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
HDL-mediated efflux of intracellular cholesterol is impaired in fibroblasts from Tangier disease patients.
pubmed:affiliation
Institute for Clinical Chemistry and Laboratory Medicine, University of Regensburg, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't