Abstract:
:The cellular mechanisms responsible for the lipoprotein-mediated stimulation of bile acid synthesis in cultured rat hepatocytes were investigated. Adding 280 micrograms/ml of cholesterol in the form of human or rat low density lipoprotein (LDL) to the culture medium increased bile acid synthesis by 1.8- and 1.6-fold, respectively. As a result of the uptake of LDL, the synthesis of [14C]cholesterol from [2-14C]acetate was decreased and cellular cholesteryl ester mass was increased. Further studies demonstrated that rat apoE-free LDL and apoE-rich high density lipoprotein (HDL) both stimulated bile acid synthesis 1.5-fold, as well as inhibited the formation of [14C]cholesterol from [2-14C]acetate. Reductive methylation of LDL blocked the inhibition of cholesterol synthesis, as well as the stimulation of bile acid synthesis, suggesting that these processes require receptor-mediated uptake. To identify the receptors responsible, competitive binding studies using 125I-labeled apoE-free LDL and 125I-labeled apoE-rich HDL were performed. Both apoE-free LDL and apoE-rich HDL displayed an equal ability to compete for binding of the other, suggesting that a receptor or a group of receptors that recognizes both apolipoproteins is involved. Additional studies show that hepatocytes from cholestyramine-treated rats displayed 2.2- and 3.4-fold increases in the binding of apoE-free LDL and apoE-rich HDL, respectively. These data show for the first time that receptor-mediated uptake of LDL by the liver is intimately linked to processes activating bile acid synthesis.
journal_name
J Lipid Resjournal_title
Journal of lipid researchauthors
Junker LH,Davis RAsubject
Has Abstractpub_date
1989-12-01 00:00:00pages
1933-41issue
12eissn
0022-2275issn
1539-7262journal_volume
30pub_type
杂志文章abstract::The ability to exogenously present cell-surface receptors in high-affinity conformations in a synthetic system offers an opportunity to provide host cells with protection from pathogenic toxins. This strategy requires improvement of the synthetic receptor binding affinity against its native counterpart, particularly w...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M007401
更新日期:2010-09-01 00:00:00
abstract::The effect of inhibiting lysosomal protein degradation on the activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase was determined using a mouse mammary cell line (TS-85) which expresses a temperature-sensitive mutation in the ubiquitin degradative pathway. Incubating cells for 18 hr in medium containi...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1986-03-01 00:00:00
abstract::The acute-phase response (APR) leads to alterations in lipid metabolism and type II nuclear hormone receptors, which regulate lipid metabolism, are suppressed, in liver, heart, and kidney. Here, we examine the effect of the APR in adipose tissue. In mice, lipopolysaccharide produces a rapid, marked decrease in mRNA le...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M500540-JLR200
更新日期:2006-10-01 00:00:00
abstract::Hepatocytes and hepatic stellate cells play important roles in retinoid storage and metabolism. Hepatocytes process postprandial retinyl esters and are responsible for secretion of retinol bound to retinol-binding protein (RBP) to maintain plasma retinol levels. Stellate cells are the body's major cellular storage sit...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:2000-06-01 00:00:00
abstract::EPA and DHA are not biologically equivalent; however, their individual activity on B cells is unknown. We previously reported fish oil enhanced murine B-cell activity in obesity. To distinguish between the effects of EPA and DHA, we studied the ethyl esters of EPA and DHA on murine B-cell function as a function of tim...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M049809
更新日期:2014-07-01 00:00:00
abstract::Endothelial lipase (EL) has been shown to be a critical determinant for high density lipoprotein cholesterol levels in vivo; therefore, assays that measure EL activity have become important for the discovery of small molecule inhibitors that specifically target EL. Here, we describe fluorescent Bodipy-labeled substrat...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.D600041-JLR200
更新日期:2007-02-01 00:00:00
abstract::Lipoprotein lipase (LPL) and hepatic lipase (HL) mediate the hydrolysis of triglycerides and phospholipids present in circulating lipoprotein particles and are essential for normal lipid metabolism. Both enzymes have a similar primary amino acid structure and share requirements for intact catalytic, lipid binding, and...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1993-08-01 00:00:00
abstract::Three pentadecynoic acids, with the triple bond in the 8-, 9-, and 10-positions, have been synthesized on a gram scale in over-all yield of 65% by refinements of the five-step Ahmad-Strong method; isolation of intermediates was shown to be unnecessary prior to purification of the acetylenic nitriles by column chromato...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1969-11-01 00:00:00
abstract::Labeled cholesterol esters were incorporated into chylomicrons in vitro by adding an acetone solution of the cholesterol ester to a suspension of washed chylomicrons. The physical and metabolic properties of the added labeled ester were the same as those of cholesterol esters incorporated into chylomicrons in vivo, ex...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1966-09-01 00:00:00
abstract::Guinea pig gallbladder bile contains chenodeoxycholic acid (62 +/- 5%), ursodeoxycholic acid (8 +/- 5%), and 7-ketolithocholic acid (30 +/- 5%). All three bile acids became labeled to the same specific activity within 30 min after [3H]cholesterol was injected into bile fistula guinea pigs. When a mixture of [3H]ursode...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1990-07-01 00:00:00
abstract::Protein palmitoylation refers to the posttranslational addition of a 16 carbon fatty acid to the side chain of cysteine, forming a thioester linkage. This acyl modification is readily reversible, providing a potential regulatory mechanism to mediate protein-membrane interactions and subcellular trafficking of proteins...
journal_title:Journal of lipid research
pub_type: 杂志文章,评审
doi:10.1194/jlr.R600007-JLR200
更新日期:2006-06-01 00:00:00
abstract::Lysophosphatidylcholine (lysoPC) is a bioactive phospholipid that is involved in atherogenesis and inflammatory processes. However, the present understanding of mechanisms whereby lysophosphatidylcholine exerts its pathophysiological actions is incomplete. In the present work, we show that lysoPC stimulates phospholip...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1999-06-01 00:00:00
abstract::Lipid-containing deposits within the swim bladders of Coryphaenoides acrolepis and Antimora rostrata were investigated. Lipid analysis of this material, which was quite uniform from the two species, yielded the following data: neutral lipids, 36.0-41.7%; phospholipids, 53.6-56.7%; and glycolipids, 4.3-8.9%. Cholestero...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1971-05-01 00:00:00
abstract::A method has been developed for rapidly quantitating the cholesterol concentration of normal and certain variant lipoproteins in a large number of patients (over 240 in one week). The method employs a microcomputer interfaced to the vertical autoprofiler (VAP) described earlier (Chung et al. 1981. J. Lipid Res. 22: 10...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1982-08-01 00:00:00
abstract::Consumption of industrially produced trans fatty acids (IP-TFA) has been positively associated with systemic markers of low-grade inflammation and endothelial dysfunction in cross-sectional studies, but results from intervention studies are inconclusive. Therefore, we conducted a 16 week double-blind parallel interven...
journal_title:Journal of lipid research
pub_type: 杂志文章,随机对照试验
doi:10.1194/jlr.M014738
更新日期:2011-10-01 00:00:00
abstract::Triglyceride-rich lipoproteins derived from ten normo- and hyperlipidemic apoE-2 homozygotes were analyzed for their composition, beta-VLDL content, and their ability to induce cholesteryl ester storage in macrophages. In six of these probands apoE sequence analysis revealed that the cysteine residues were at position...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1985-03-01 00:00:00
abstract::ZR-78 and ZR-82 cells are two peroxisomal-deficient Chinese hamster ovary (CHO) cell mutants. These cells lack normal peroxisomes and show reduced levels of plasmalogen synthesis and other peroxisomal functions attributed to the deficiency of peroxisomal matrix enzymes. As we have recently identified two HMG-CoA reduc...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1998-09-01 00:00:00
abstract::The differentiation of macrophages into lipid-filled foam cells is a hallmark of the lung granuloma that forms in patients with active tuberculosis (TB). Mycolic acids (MAs), the abundant lipid virulence factors in the cell wall of Mycobacterium tuberculosis (Mtb), can induce this foam phenotype possibly as a way to p...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M073171
更新日期:2017-04-01 00:00:00
abstract::The formation of cholic acid from 3alpha, 7alpha, 12alpha-trihydroxy-5beta-cholestan-26-oic acid (THCA) was studied in two normal subjects. [3H]THCA and [14C]cholic acid were administered intravenously by simultaneous injection and the specific activities (percent injected amount/mumol) of [3H]- and [14C]cholic acid w...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1977-09-01 00:00:00
abstract::We investigated the formation and pharmacology of prostaglandin E(3) (PGE(3)) derived from fish oil eicosapentaenoic acid (EPA) in human lung cancer A549 cells. Exposure of A549 cells to EPA resulted in the rapid formation and export of PGE(3.) The extracellular ratio of PGE(3) to PGE(2) increased from 0.08 in control...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M300455-JLR200
更新日期:2004-06-01 00:00:00
abstract::Cystic fibrosis (CF) patients and model systems exhibit consistent abnormalities in PUFA metabolism, including increased metabolism of linoleate to arachidonate. Recent studies have connected these abnormalities to increased expression and activity of the Δ6- and Δ5-desaturase enzymes. However, the mechanism connectin...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M050369
更新日期:2014-07-01 00:00:00
abstract::There is a continuous flux of the oxysterol 27-hydroxycholesterol (27-OHC) from the circulation across the blood-brain barrier (BBB) into the brain. The major metabolite of 27-OHC in the brain is 7α-hydroxy-3-oxo-4-cholestenoic acid (7-HOCA). We confirm a recent report describing the presence of this metabolite in cer...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.P044982
更新日期:2014-02-01 00:00:00
abstract::In human serum, polymorphism of apoA-II predominantly in HDL3 could be demonstrated. HDL3-apoA-II was composed of four isoproteins, each with a molecular weight of 8600 (reduced form) and identical immunological properties. The isoproteins are designated apoA-II-1 (pI 5.16), apoA-II-2 (pI 4.89) corresponding to the al...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1983-08-01 00:00:00
abstract::The primary structure of apolipoprotein A-II (apoA-II) isolated from the plasma high density lipoprotein (HDL) fraction of the inbred mouse strain BALB/c is described in this work. The complete 78 amino acid protein sequence was determined by proteolytic fragmentation, gas-phase microsequence analysis, and fast atom b...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1987-03-01 00:00:00
abstract::Triacylglycerols (TG) are the major storage form of energy in eukaryotic organisms and are synthesized primarily by acyl CoA:1,2-diacylglycerol acyltransferase (DGAT) enzymes. In vitro DGAT activity has previously been quantified by measuring the incorporation of either radiolabeled fatty acyl CoA or diacylglycerol (D...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.D016626
更新日期:2011-09-01 00:00:00
abstract::Acetyl-L-carnitine is known as a reservoir of activated acetyl units and as a modulator of metabolic function. The objective of this study was to quantify the fate of the acetyl moiety of acetyl-L-carnitine in lipogenic pathways. Lipogenesis was studied in an adipocyte model, differentiated 3T3-L1 cells, and a hepatom...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1997-07-01 00:00:00
abstract::Here, we present an improved method for sensitive profiling of lipids in a single high-performance liquid chromatography-electrospray ionization-quadrupole time of flight mass spectrometry experiment. The approach consists of i) sensitive isocratic elution, which takes advantage of C18 column material that is resistan...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M700060-JLR200
更新日期:2007-09-01 00:00:00
abstract::The biosynthesis of prostaglandins by isolated rat adrenocortical cells has been studied by determinations of products formed during incubations with labeled arachidonic acid and by radioimmunoassays. Analysis by thin-layer chromatographic separation of silicic acid column fractions indicated that PGE2, PGA2, (B2) and...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1979-01-01 00:00:00
abstract::Conditions under which apolipoprotein (apo) A-I dissociates from human high density lipoproteins (HDL) during incubation in vitro have been investigated. Dissociation of apoA-I was demonstrated by non-denaturing gradient gel electrophoresis followed by immunoblotting for apoA-I and by size-exclusion chromatography. It...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1994-07-01 00:00:00
abstract::The Singer-Nicholson model of membranes postulated a uniform lipid bilayer randomly studded with floating proteins. However, it became clear almost immediately that membranes were not uniform and that clusters of lipids in a more ordered state existed within the generally disorder lipid milieu of the membrane. These c...
journal_title:Journal of lipid research
pub_type: 杂志文章,评审
doi:10.1194/jlr.R800040-JLR200
更新日期:2009-04-01 00:00:00