Abstract:
:The present studies tested the hypothesis that some effects of tumor necrosis factor-alpha (TNF-alpha) are mediated by activation of sphingomyelinases and the production of ceramides. Differentiated 3T3-L1 adipocytes were incubated with short-chain ceramide analogs, (C2- and C6-ceramides: N-acetyl- and N-hexanoyl-sphingosines, respectively), and this treatment increased 2-deoxyglucose uptake in the absence of insulin progressively from 2-24 h. This effect was inhibited by blocking the activations of mitogen-activated protein kinase, phosphatidylinositol 3-kinase (PI 3-kinase), and ribosomal S6 kinase which mediated an increase in GLUT1 concentrations. Long-term increases in PI 3-kinase activity associated with insulin receptor substrate-1 (IRS-1) increased the proportion of GLUT1 and GLUT4 in plasma membranes. These events explain the increases in noninsulin-dependent glucose uptake and incorporation of this glucose into the fatty acid and glycerol moieties of triacylglycerol. The mechanisms by which TNF-alpha and ceramides increase PI 3-kinase activity were investigated further by using rat2 fibroblasts. Incubation for 20 min with TNF-alpha, bacterial sphingomyelinase, or C2-ceramides increased PI 3-kinase activity by about fivefold, and this effect depended upon a stimulation of tyrosine kinase activity and an increase in Ras-GTP. This demonstrates the existence of a novel signaling pathway for TNF-alpha that could contribute to the effects of this cytokine in stimulating basal glucose uptake. By contrast, treating the 3T3-L1 adipocytes for 2-24 h with C2-ceramide diminished insulin-stimulated glucose uptake by decreasing the insulin-induced translocation of GLUT1 and GLUT4 to plasma membranes. This inhibition was observed when there was no increase in basal glucose uptake, and it occurred downstream of PI 3-kinase. Our work provides further mechanisms whereby TNF-alpha and ceramides produce insulin resistance and decrease the effectiveness of insulin in stimulating glucose disposal from the blood. Conversely, TNF-alpha and ceramides increase the ability of adipocytes to take up glucose and store triacylglycerol in the absence of insulin.
journal_name
Lipidsjournal_title
Lipidsauthors
Brindley DN,Wang CN,Mei J,Xu J,Hanna ANdoi
10.1007/BF02562240subject
Has Abstractpub_date
1999-01-01 00:00:00pages
S85-8eissn
0024-4201issn
1558-9307journal_volume
34 Supplpub_type
杂志文章相关文献
LIPIDS文献大全abstract::Dietary fat and abnormal production of various prostanoids have been linked to various disease states of the large bowel, including cancer of the colon. Studies were conducted to determine the effect of dietary fat (beef tallow or corn oil) on the lipid composition and prostanoid production of the murine colon. Female...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/BF02537344
更新日期:1988-04-01 00:00:00
abstract::Neuronal membranes are highly enriched with docosahexaenoic acid (22:6n-3), and its content can be altered by ethanol consumption. We have previously reported that the 22:6n-3 status in membrane affects the biosynthesis of phosphatidylserine (PS), a phospholipid class which contains an exceptionally high proportion of...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/BF02664769
更新日期:2000-02-01 00:00:00
abstract::The influence of dietary TAG source (fish oil, triolein, and coconut oil) and level (7.5 and 15% of the diet) on growth, lipase activity, and mRNA level was studied in sea bass larvae, from mouth opening until day 24 and from day 37 to 52. Fish oil and triolein induced better growth in both experiments, this being sig...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/s11745-004-1250-2
更新日期:2004-05-01 00:00:00
abstract::Thermally oxidized rapeseed oils (4 levels of deterioration; used by a manufacturer of fried fish paste in a conventional manner) were fed to rats at a practical level of concentration. Rats were fed a diet ad libitum for 13 weeks that contained 15% of a test oil. The effects of the diet on several biochemical criteri...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/BF02534782
更新日期:1984-05-01 00:00:00
abstract::Peroxidation of intact human erythrocytes by t-butylhydroperoxide (tBHP)) was studied. By incubation of the erythrocytes with 1 mM tBHP, reduced glutathione (GSH) was exhausted within 1 min, and tocopherols (Toc) and phospholipids (PL) decreased to nearly their lowest levels (in this study) within 5 min. The rate of d...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/s11745-001-0668-x
更新日期:2001-01-01 00:00:00
abstract::HMG-CoA reductase (HMGCR) is an enzyme involved in cholesterol synthesis. To investigate the contribution of the HMGCR gene to lipids and lipoprotein subfractions in different ethnicities, we performed an association study in the Multi-Ethnic Study of Atherosclerosis (MESA). In total, 2,444 MESA subjects [597 African-...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/s11745-009-3314-6
更新日期:2009-08-01 00:00:00
abstract::Orally administered dihomo-gamma-linolenic acid (DHLA) is well absorbed in man; it appears in blood after ca. 4 hr first as triglyceride ester and later as phospholipid. After sustained-dosing, DHLA penetrated membrane pools and all phospholipid components but, depending on the dosage, reached a metabolic equilibrium ...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/BF02533869
更新日期:1979-02-01 00:00:00
abstract::Conjugated linoleic acid (CLA) has been demonstrated to reduce body fat in animals. However, the mechanism by which this reduction occurs is unknown. Leptin may mediate the effect of CLA to decrease body fat. We assessed the effects of 64 d of CLA supplementation (3 g/d) on circulating leptin, insulin, glucose, and la...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/s11745-000-0586-y
更新日期:2000-07-01 00:00:00
abstract::[1-14C]alpha-Linolenic acid was incubated with a particulate fraction of homogenate of leaves of the meadow buttercup (Ranunculus acris L.). The main product was a divinyl ether fatty acid, which was identified as 12-[1'(Z),3'(Z)-hexadienyloxy]-9(Z),11(E)-dodecadienoic acid. Addition of glutathione peroxidase and redu...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/s11745-998-0306-7
更新日期:1998-11-01 00:00:00
abstract::Lipophilic toxins have been introduced into the environment both as functional compounds, such as pesticides, and as industrial waste from incineration or the manufacture of electrical transformer components. Among these substances are compounds that are carcinogenic and that affect the endocrine system. Accidental hi...
journal_title:Lipids
pub_type: 杂志文章,评审
doi:10.1007/s11745-001-0844-z
更新日期:2001-12-01 00:00:00
abstract::An increased amount of phospholipids remained attached on delipidated apolipoprotein B originated from oxidized low density lipoprotein (LDL). 31P nuclear magnetic resonance analysis of such apolipoprotein showed an organic phosphorus peak at -0.55 ppm, which suggests the formation of adducts (most probably Schiff bas...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/s11745-998-0318-3
更新日期:1998-12-01 00:00:00
abstract::Ceramide 2-aminoethylphosphonate (CAEP), a sphingophosphonolipid containing a carbon-phosphorus bond, is frequently found in marine organisms and has a unique triene type of sphingoid base in its structure. CAEP has not been evaluated as a food ingredient, although it is generally contained in Mollusca organisms such ...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/s11745-017-4239-0
更新日期:2017-04-01 00:00:00
abstract::The degradation of alpha-tocopherol and the formation of alpha-tocopherol and triacylglycerol oxidation products at high temperatures (150-250 degrees C) over a heating period (0-4 h) for a model system ranging between triolein and tripalmitin were modeled by use of an experimental design. The oxidation products of al...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/s11745-001-0777-6
更新日期:2001-07-01 00:00:00
abstract::The effects of hyper- and hypothyroidism on enzyme activities involved in phospholipid metabolism in the rat liver were studied. Hyperthyroidism significantly decreases activities of both microsomal acyl-CoA:glycero-3-phosphate acyltransferase (GPAT) (34%, p less than 0.01) and microsomal acyl-CoA:1-acylglycero-3-phos...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/BF02534774
更新日期:1985-12-01 00:00:00
abstract::The all-cis-5,9,12-heptadecatrienoic acid was identified in the cellular slime mold Polysphondylium pallidum. The structural elucidation was accomplished by capillary gas chromatography, argentation thin-layer chromatography, and gas chromatography/mass spectrometry. This fatty acid has not been reported previously. ...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/BF02522934
更新日期:1996-04-01 00:00:00
abstract::The schweinfurthins have potent antiproliferative activity in multiple glioblastoma multiforme (GBM) cell lines; however, the mechanism by which growth is impeded is not fully understood. Previously, we demonstrated that the schweinfurthins reduce the level of key isoprenoid intermediates in the cholesterol biosynthet...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/s11745-015-4083-z
更新日期:2015-12-01 00:00:00
abstract::The concentrations of nonesterified fatty acids and glycerol in rat parametrial adipose tissue increased at peak lactation. Adipose tissue from lactating rats showed higher rates of release of nonesterified fatty acids and glycerol when incubated in vitro than did tissue from nonlactating rats, but there was a substan...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/BF02532850
更新日期:1976-05-01 00:00:00
abstract::Factors involved in reduced glutathione (GSH) and vitamin E-mediated inhibition of NADPH-dependent rat liver microsomal lipid peroxidation were examined. Lipid peroxidation was monitored over a time-course of 180 min by thiobarbituric acid reactive product formation. The addition of 5 mM GSH to the reaction system con...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/BF02544533
更新日期:1989-11-01 00:00:00
abstract::Primary cultured hepatocytes from normal mice and mice with Sarcoma 180 were characterized. The viability of freshly isolated hepatocytes from both sources was over 90% and the cells had a relatively stable population of DNA for a minimum of three days. After incubation with (3H)leucine, the syntheses and secretions o...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/BF02534229
更新日期:1985-07-01 00:00:00
abstract::Serum high density lipoprotein is increasingly recognized as a negative risk for cardiovascular disease. The distribution and interrelationship of serum lipids, lipoproteins, anthropometric measurements and blood pressures were determined in some 5,000 children. Children had mean +/- S.D. alpha-lipoprotein cholesterol...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/BF02533576
更新日期:1979-01-01 00:00:00
abstract::Epoxidation of the double bond in methyl oleate, octadec-11E-en-9-ynoate, ricinoleate (12-hydroxy-octadec-9Z-enoate), iso-ricinoleate (9-hydroxy-octadec-12Z-enoate), and 12-oxo-octadec-9Z-enoate with potassium peroxomonosulfate (oxone, 2 KHSO5.KHSO4.K2SO4) in the presence of trifluoroacetone or methyl pyruvate gave th...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/s11745-998-0250-6
更新日期:1998-06-01 00:00:00
abstract::The production of cardiac arrhythmias and the elevation of lysophosphatidylcholine level in the ischemic myocardium have been well-documented in a number of studies. However, the relationship between the production arrhythmias and the elevation of tissue lysophosphatidylcholine level was not reported. In this study, t...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/BF02535301
更新日期:1988-01-01 00:00:00
abstract::Using an experimental model that enables the effects of alcohol to be distinguished from the effects of the nonalcoholic components present in wine, we determined whether wine has effects other than those of alcohol on the metabolism of cholesterol. Male rats were fed a standard diet and had free access to water and e...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/s11745-001-0732-6
更新日期:2001-04-01 00:00:00
abstract::This study investigated the effect of triticale dried distillers' grain with solubles (DDGS), flax (FS) and sunflower (SS) seed on growth and the fatty acid profile of subcutaneous (SQ) fat in individually housed steers (n = 15 per diet) fed ad libitum (DM basis); (1) control (CON) 90% barley grain + 10% barley silage...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/s11745-012-3720-z
更新日期:2012-12-01 00:00:00
abstract::Choline kinase was located in the cytosolic fractions of the filamentous, pathogenic fungi,Microsporum gypseum andEpidermophyton floccosum. A broad pH optima (6.0-9.0) was observed for theM. gypseum enzyme, but theE. floccosum enzyme was active at pH 8.4 as well as 10.5, the activity being higher at pH 8.4. Enzyme fro...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/BF02534540
更新日期:1983-10-01 00:00:00
abstract::A group of Angus beef cattle was removed from temperate pastures and fed a very low beta-carotene cereal-based ration in a feedlot for over 300 d. Half the group was supplemented weekly with retinyl palmitate (at the rate of 60,000 IU vitamin A/100 live weight (LW)/day), sufficient to offset clinical vitamin A deficie...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/s11745-006-5107-5
更新日期:2006-04-01 00:00:00
abstract::The purpose of these experiments was to study the uptake and metabolism of exogenous triglyceride in the isolated perfused rabbit heart. When infused into the rabbit heart, [9,10-3H(N)]triolein was retained and incorporated into a lipid fraction that had the chromatographic mobility of authentic triolein. Incorporatio...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/BF02538094
更新日期:1990-08-01 00:00:00
abstract::In animals, non-sterol metabolites of the mevalonate pathway act independently from receptor-mediated cholesterol uptake in the multivalent feedback regulation of mevalonate biosynthesis. Studies leading to the isolation and characterization of plant-borne suppressors of mevalonate biosynthesis are reviewed. We propos...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/BF02534407
更新日期:1985-11-01 00:00:00
abstract::The pulp from unerupted calves' teeth was found to contain low levels of glycerol ester hydrolase activity. Solutions in Tris buffer cleared tributyrylglycerol agar and hydrolyzed emulsified olive oil. The average quantity of free fatty acids released in five assays with olive oil was: 2.8, S.D.+/-1.4. Specific activi...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/BF02533302
更新日期:1977-02-01 00:00:00
abstract::In view of the findings that omega 3 fatty acids inhibit the synthesis of prostaglandins (PG) from arachidonic acid (20:4 omega 6) and that among immunologically active cells, the macrophage is a major producer of PG, we undertook a study of the effect of dietary alpha-linolenic acid (18:3 omega 3) on PG synthesis in ...
journal_title:Lipids
pub_type: 杂志文章
doi:10.1007/BF02535390
更新日期:1983-08-01 00:00:00