Abstract：
:The formation of hepatic bile requires that water be transported across liver epithelia. Rat hepatocytes express three aquaporins (AQPs): AQP8, AQP9, and AQP0. Recognizing that cholesterol and sphingolipids are thought to promote the assembly of proteins into specialized membrane microdomains, we hypothesized that canalicular bile secretion involves the trafficking of vesicles to and from localized lipid-enriched microdomains in the canalicular plasma membrane. Hepatocyte plasma membranes were sonicated in Triton and centrifuged overnight on a sucrose gradient to yield a Triton-soluble pellet and a Triton-insoluble, sphingolipid-enriched microdomain fraction at the 5%/30% sucrose interface. The detergent-insoluble portion of the hepatocyte plasma membrane was enriched in alkaline phosphatase (a microdomain-positive marker) and devoid of amino-peptidase N (a microdomain-negative marker), enriched in caveolin, both AQP8 and AQP9, but negative for clathrin. The microdomain fractions contained chloride-bicarbonate anion exchanger isoform 2 and multidrug resistance-associated protein 2. Exposure of isolated hepatocytes to glucagon increased the expression of AQP8 but not AQP9 in the microdomain fractions. Sphingolipid analysis of the insoluble fraction showed the predominant species to be sphingomyelin. These data support the presence of sphingolipid-enriched microdomains of the hepatocyte membrane that represent potential localized target areas for the clustering of AQPs and functionally related proteins involved in canalicular bile secretion.
journal_name
J Lipid Resjournal_title
Journal of lipid researchauthors
Tietz P,Jefferson J,Pagano R,Larusso NFdoi
10.1194/jlr.M400412-JLR200keywords:
subject
Has Abstractpub_date
2005-07-01 00:00:00pages
1426-32issue
7eissn
0022-2275issn
1539-7262pii
M400412-JLR200journal_volume
46pub_type
杂志文章abstract：:The action of cycloheximide on some parameters of glucose and lipid metabolism was studied in vitro in epidiymal fat pads from fasted rats. Incubation of fat pads with cycloheximide (1 mug/ml) for 2 hours resulted in a two-fold increase in glucose uptake, glucose oxidation, incorporation of glucose into lipids, and re...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1977-01-01 00:00:00
abstract：:Investigations of the topography of glycerolipid synthetic enzymes within the transverse plane of microsomal vesicles indicated an exclusive cytoplasmic surface location of active sites. Evidence was derived from studies employing proteases and other impermeant inhibitors, from investigations of latency and substrate ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1981-03-01 00:00:00
abstract：:An enzyme (phosphatidyl glycerophosphate phosphatase) that catalyzes the formation of phosphatidyl glycerol from phosphatidyl glycerophosphate has been rendered soluble by treatment of the particulate fraction of E. coli with Triton X-100 in the presence of EDTA, and has been partially purified. The enzyme is specific...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1967-09-01 00:00:00
abstract：:We describe new methods for analyzing the apolipoproteins (apo) of the high density lipoproteins (HDL) of several species by two modes of capillary electrophoresis: size separation using a molecular sieving buffer, and capillary zone electrophoresis (CZE) using neutral coated capillaries. By either mode HDL apos were ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1998-01-01 00:00:00
abstract：:Cigarette smokers have reduced levels of plasma high density lipoprotein (HDL) compared to nonsmokers and are at risk of premature cardiovascular disease. Previous work from this laboratory has shown that exposure of human plasma to gas-phase cigarette smoke (CS) inhibited the activity of lecithin:cholesterol acyltran...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1995-02-01 00:00:00
abstract：:Several recent reports have examined whether there is a correlation between the presence of some minor alleles of the highly polymorphic apolipoprotein B gene and atherosclerosis and premature heart disease. The present study extends this investigation. A high-resolution method was used to study the allele frequencies...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1990-04-01 00:00:00
abstract：:Several studies have documented the presence of Lp[a] in nonhuman primates. However, data are lacking in great apes such as the chimpanzee. We have studied the quantitative distribution of Lp[a], as well as the frequency of apo[a] phenotypes, in a population of chimpanzees living in Gabon. Monoclonal antibody 14A12, d...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1994-02-01 00:00:00
abstract：:After stereospecific oxidation, trimethylsilylated methyl esters of mono- and diunsaturated fatty acids were analyzed by combined gas-liquid chromatography-chemical ionization mass spectrometry. The positions of original double bonds were deduced from the fragment ions produced by the cleavage of the carbon-carbon bon...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1978-02-01 00:00:00
abstract：:Liver cells isolated from normal and cholestyramine-treated rats were incubated as cell suspensions for up to 4 hr in a simple, defined medium. The bile acid concentration in cells plus cell medium was determined by gas-liquid chromatography. Normal hepatocytes synthesized cholic acid at an initial rate of 0.25 nmol/m...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1979-09-01 00:00:00
abstract：:Epoxyeicosatrienoic acids were isolated and purified from female rabbit kidneys. They were identified as a group, prior to resolution, by packed column gas-liquid chromatography-mass spectroscopic techniques as their methyl esters as well as their trimethylsilyl bromohydrin methyl esters. Initial capillary gas-liquid ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1987-07-01 00:00:00
abstract：:The interaction of hepatic lipase (HL) with heparan sulfate is critical to the function of this enzyme. The primary amino acid sequence of HL was compared to that of lipoprotein lipase (LPL), a related enzyme that possesses several putative heparin-binding domains. Of the three putative heparin-binding clusters of LPL...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：2000-02-01 00:00:00
abstract：:Hormone-sensitive lipase (HSL) catalyzes the rate-limiting step in adipocyte lipolysis. The activity of HSL is thought to be primarily regulated by reversible phosphorylation. However, the regulation of HSL activity by pre-translational mechanisms has been poorly studied. The present studies were undertaken to explore...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1998-08-01 00:00:00
abstract：:An improved preparation of proteolipid from bovine brain white matter is described. The product obtained by repeated acetone precipitation is completely soluble in chloroform-methanol and has a fairly constant composition: 35% protein, 40% galactocerebroside, and about 25% phospholipid. ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1967-01-01 00:00:00
abstract：:Changes in chromatin structure regulate gene expression and genome maintenance. Molecules that bind to the nucleosome, the complex of DNA and histone proteins, are key modulators of chromatin structure. Previous work indicated that cholesterol, a ubiquitous cellular lipid, may bind to chromatin in vivo, suggesting a p...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M074997
更新日期：2017-05-01 00:00:00
abstract：:Ricinoleic acid (12-hydroxyoctadec-cis-9-enoic acid) has many specialized uses in bioproduct industries, while castor bean is currently the only commercial source for the fatty acid. This report describes metabolic engineering of a microbial system (Pichia pastoris) to produce ricinoleic acid using a "push" (synthesis...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M060954
更新日期：2015-11-01 00:00:00
abstract：:In mammals, white adipose tissue (WAT) stores and releases lipids, whereas brown adipose tissue (BAT) oxidizes lipids to fuel thermogenesis. In obese individuals, WAT undergoes profound changes; it expands, becomes dysfunctional, and develops a low-grade inflammatory state. Importantly, BAT content and activity declin...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M079665
更新日期：2018-05-01 00:00:00
abstract：:Low concentrations of oxidized low density lipoprotein (OxLDL) are cytoprotective for phagocytes, although the underlying mechanisms remain unclear. We investigated signaling pathways used by OxLDL to attenuate apoptosis in monocytic cells. OxLDL at 25-50 mug/ml inhibited staurosporine-induced apoptosis in THP-1 cells...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M700100-JLR200
更新日期：2008-01-01 00:00:00
abstract：:Recent findings suggest that the effects of cholestyramine and psyllium in combination could be additive for cholesterol-lowering. We therefore examined the effect of both agents, alone and in combination, on lipoprotein cholesterol and neutral and acidic steroid excretion in the hamster. Animals (n = 8/group) were fe...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1997-03-01 00:00:00
abstract：:The sphingomyelin pathway is an important signal transduction system regulating various cellular functions. However, little is known about the effect of sphingomyelin metabolites on vasomotor function. We examined the vascular effects of sphingomyelin, sphingosine, and sphingomyelinase (SPMase) in vitro. In pig corona...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1996-07-01 00:00:00
abstract：:apoM is a member of the lipocalin superfamily and circulates in plasma attached to HDL particles. apoM plays a role in cholesterol metabolism and has recently been identified as transporter for the signaling lipid, sphingosine-1-phosphate (S1P), in plasma. S1P is implicated in several inflammatory diseases such as mul...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.D055947
更新日期：2015-03-01 00:00:00
abstract：:These studies examined the proposition that the small particle size of HDL3 in the plasma of hypertriglyceridemic subjects is the consequence of the sequential actions of lipid transfer protein and hepatic lipase on HDL. Incubation of unmodified total HDL or HDL3 in the presence of hepatic lipase resulted in a depleti...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1986-12-01 00:00:00
abstract：:The phase behavior and temperature-dependent molecular motions of three cholesteryl ethers (caproyl, myristyl, oleyl) and a cholesteryl carbonate (oleyl) were characterized. The properties of each ether were qualitatively similar to, but quantitatively different from, those of the corresponding cholesteryl ester. For ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1987-12-01 00:00:00
abstract：:Two new 6-hydroxylated bile acids, 3 beta, 6 alpha, 12 alpha- and 3 beta, 6 beta, 12 alpha-trihydroxy-5 beta-cholanoic acids, were synthesized from deoxycholic acid. In addition, their C-3 epimers, 3 alpha, 6 alpha, 12 alpha- and 3 alpha, 6 beta, 12 alpha-trihydroxy acids, were prepared by a new route. The principal r...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1991-04-01 00:00:00
abstract：:In addition to their classical roles as detergents to aid in the process of digestion, bile acids have been identified as important signaling molecules that function through various nuclear and G protein-coupled receptors to regulate a myriad of cellular and molecular functions across both metabolic and nonmetabolic p...
journal_title：Journal of lipid research
pub_type： 杂志文章,评审
doi：10.1194/jlr.R054114
更新日期：2015-06-01 00:00:00
abstract：:This study aimed at measuring the influence of a low salt diet on the development of experimental atherosclerosis in moderately hyperlipidemic mice. Experiments were carried out on LDL receptor (LDLR) knockout (KO) mice, or apolipoprotein E (apoE) KO mice on a low sodium chloride diet (LSD) as compared with a normal s...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M200330-JLR200
更新日期：2003-04-01 00:00:00
abstract：:High density lipoproteins (HDL) were isolated by a chromatographic procedure and subsequently fractionated on a DEAE cellulose (DE-52) column. Four fractions were separated and analyzed for lipid and protein composition and molecular weight. During ion exchange chromatography, one of the four fractions consistently co...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1981-09-01 00:00:00
abstract：:HDL plays crucial roles at multiple stages of the pathogenesis of atherosclerosis. AMP-activated protein kinase (AMPK) is a therapeutic candidate for the treatment of cardiovascular disease. However, the effect of AMPK activation on HDL functionality has not been established in vivo. We assessed the effects of pharmac...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M073270
更新日期：2017-08-01 00:00:00
abstract：:We have previously observed that the Ya subunit-containing glutathione (GSH) S-transferases from rat liver exhibit a common high affinity binding site for lithocholic acid, bilirubin, and sulfobromophthalein (BSP) (1984. J. Lipid Res. 25: 1177-1183). Subsequently we found that cholic acid and its amidates bound to a s...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1988-03-01 00:00:00
abstract：:Lipid lamellae present in the outermost layer of the skin, the stratum corneum, form the main barrier for the diffusion of molecules through the skin. The presence of a unique 13 nm lamellar phase and its high crystallinity are characteristic for the stratum corneum lipid phase behavior. In the present study, small-an...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M500221-JLR200
更新日期：2005-12-01 00:00:00
abstract：:Fatty acid translocase (FAT/CD36) is a membrane protein putatively involved in the transmembrane transport of long-chain fatty acids. We tested the hypothesis that expression of this protein in H9c2, a rat heart cell line normally not expressing FAT, would increase cellular palmitate uptake. We were able to stably tra...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1998-10-01 00:00:00
