scholarly journals Incorporation of lipoxygenase products into cholesteryl esters by acyl-CoA:cholesterol acyltransferase in cholesterol-rich macrophages

1988 ◽  
Vol 256 (3) ◽  
pp. 807-814 ◽  
Author(s):  
S N Mathur ◽  
E Albright ◽  
F J Field
Keyword(s):  
Fatty Acids ◽  
Foam Cell ◽  
Fatty Acyl ◽  
Hydroxy Fatty Acids ◽  
Cholesteryl Esters ◽  
Acat Activity ◽  
Lipoxygenase Products ◽  
First Time ◽  
Total Membrane ◽  
Cholesteryl Ester Accumulation

Macrophages which were incubated with acetylated low-density lipoproteins, resulting in cholesteryl ester accumulation, incorporated the monohydroxyeicosatetraenoic acids (5-, 15-, and 12-HETEs) into cholesteryl esters. The esterification of these hydroxy fatty acids to cholesterol by total membrane preparations of cholesterol-rich macrophages was dependent on the synthesis of the fatty acyl-CoA derivative, and was catalysed by acyl-CoA:cholesterol acyltransferase (ACAT). Stimulation of membrane ACAT activity by 25-hydroxycholesterol increased the synthesis of cholesteryl 12-HETE by 40%. In contrast, inhibiting ACAT activity by progesterone and compound 58-035 decreased cholesteryl 12-HETE production by 60% and 90% respectively. Although 5-, 15- and 12-HETE were esterified to cholesterol by ACAT, these monohydroxy fatty acids were less optimal as substrates compared with oleic acid or arachidonic acid. The hydrolysis and release of 12-HETE and the other monohydroxyeicosatetraenoic acids from intracellular cholesteryl esters and phospholipids occurred at a faster rate than for the more conventional fatty acids, oleate and arachidonate. Cholesteryl esters which contain hydroxy fatty acids therefore provide only a transient storage for lipoxygenase products, as these fatty acids are released into the medium as readily as hydroxy fatty acids found in phospholipids and triacylglycerols. The data provide evidence, for the first time, of an ACAT-dependent esterification of the lipoxygenase products 5-, 15- and 12-HETEs to cholesterol in the macrophage-derived foam cell. The channelling of these monohydroxy fatty acids to cholesteryl esters provides a mechanism which can alter the amount of lipoxygenase products incorporated into cellular phospholipids, thus averting deleterious changes to cell membranes. ACAT, by catalysing the esterification of monohydroxyeicosatetraenoic acids to cholesterol, could play a key role in regulating the amount of lipoxygenase products in the pericellular space of the cholesterol-enriched macrophage.

scholarly journals Fatty Acyl Esters of Hydroxy Fatty Acid (FAHFA) Lipid Families

Metabolites ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 512
Author(s):  
Paul L. Wood
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Hydroxy Fatty Acid ◽  
Fatty Acyl ◽  
Hydroxy Fatty Acids ◽  
Wax Esters ◽  
Hydroxyl Group ◽  
Cellular Functions ◽  
Health And Disease ◽  
Branched Chain

Fatty Acyl esters of Hydroxy Fatty Acids (FAHFA) encompass three different lipid families which have incorrectly been classified as wax esters. These families include (i) Branched-chain FAHFAs, involved in the regulation of glucose metabolism and inflammation, with acylation of an internal branched-chain hydroxy-palmitic or -stearic acid; (ii) ω-FAHFAs, which function as biosurfactants in a number of biofluids, are formed via acylation of the ω-hydroxyl group of very-long-chain fatty acids (these lipids have also been designated as o-acyl hydroxy fatty acids; OAHFA); and (iii) Ornithine-FAHFAs are bacterial lipids formed by the acylation of short-chain 3-hydroxy fatty acids and the addition of ornithine to the free carboxy group of the hydroxy fatty acid. The differences in biosynthetic pathways and cellular functions of these lipid families will be reviewed and compared to wax esters, which are formed by the acylation of a fatty alcohol, not a hydroxy fatty acid. In summary, FAHFA lipid families are both unique and complex in their biosynthesis and their biological actions. We have only evaluated the tip of the iceberg and much more exciting research is required to understand these lipids in health and disease.

scholarly journals Analysis of Hydroxy Fatty Acids from the Pollen of Brassica campestris L. var. oleifera DC. by UPLC-MS/MS

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Nian-Yun Yang ◽  
Yi-Fang Yang ◽  
Kun Li
Keyword(s):  
Fatty Acids ◽  
Brassica Campestris ◽  
Octadecadienoic Acid ◽  
Molecular Ions ◽  
Hydroxy Fatty Acids ◽  
Hydroxyl Group ◽  
Electrospray Tandem Mass Spectrometry ◽  
Fragment Ions ◽  
First Time ◽  
Alcoholic Hydroxyl

Ultraperformance liquid chromatography coupled with negative electrospray tandem mass spectrometry (UPLC-ESI-MS/MS) was used to determine 7 hydroxy fatty acids in the pollen of Brassica campestris L. var. oleifera DC. All the investigated hydroxy fatty acids showed strong deprotonated molecular ions [M–H]−, which underwent two major fragment pathways of the allyl scission and the β-fission of the alcoholic hydroxyl group. By comparison of their molecular ions and abundant fragment ions with those of reference compounds, they were tentatively assigned as 15,16-dihydroxy-9Z,12Z-octadecadienoic acid (1), 10,11,12-trihydroxy-(7Z,14Z)-heptadecadienoic acid (2), 7,15,16-trihydroxy-9Z,12Z-octadecadienoic acid (3), 15,16-dihydroxy-9Z,12Z-octadecadienoic acid (4), 15-hydroxy-6Z,9Z,12Z-octadecatrienoic acid (5), 15-hydroxy-9Z,12Z- octadecadienoic acid (6), and 15-hydroxy-12Z-octadecaenoic acid (7), respectively. Compounds 3, 5, and 7 are reported for the first time.

scholarly journals Cholesteryl esters of ω-( O -acyl)-hydroxy fatty acids in vernix caseosa

2017 ◽  
Vol 58 (8) ◽  
pp. 1579-1590 ◽  
Author(s):  
Aneta Kalužíková ◽  
Vladimír Vrkoslav ◽  
Eva Harazim ◽  
Michal Hoskovec ◽  
Richard Plavka ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Hydroxy Fatty Acids ◽  
Cholesteryl Esters ◽  
Vernix Caseosa

Dexamethasone enhances accumulation of cholesteryl esters by human macrophages

1995 ◽  
Vol 269 (4) ◽  
pp. E642-E648 ◽  
Author(s):  
W. Cheng ◽  
K. V. Kvilekval ◽  
N. A. Abumrad
Keyword(s):  
Cholesteryl Ester ◽  
Lipid Accumulation ◽  
Statistical Significance ◽  
Human Monocyte ◽  
Cholesteryl Esters ◽  
Fourfold Increase ◽  
Acat Activity ◽  
Low Concentrations ◽  
Dose Dependent ◽  
Cholesteryl Ester Accumulation

The effects of dexamethasone on lipid accumulation by human monocyte-derived macrophages were investigated. Preincubation of macrophages with dexamethasone for a period of 16-20 h resulted in a reproducible increase (3.5-fold) in the incorporation of oleate into cholesteryl esters. The effect was specific because no alterations were observed in oleate incorporation into triglycerides or phospholipids. Measurement of cellular cholesteryl esters indicated a fourfold increase after preincubation with dexamethasone. This increase was mediated by opposite effects on synthesis and breakdown of these lipids. Dexamethasone produced a 60% increase in activity of the enzyme acyl-CoA: cholesterol O-acyltransferase (ACAT), active in synthesis of cholesteryl esters, and a 40% decrease in that of neutral cholesteryl esterase, active in cholesteryl ester breakdown. The increased ACAT activity appeared to reflect increased mRNA for the enzyme. The effects of dexamethasone on cholesteryl ester accumulation by macrophages reached statistical significance at a concentration of 100 nM. They were dose dependent, and saturation was observed at around 1 microM. The effects were significant at low concentrations of cholesterol in the medium. At high-medium cholesterol, there was a large cholesterol-induced increase in ACAT activity that obscured most of the effect of dexamethasone. In general, the data suggest that high glucocorticoid levels enhance lipid accumulation by macrophages and thus would have an atherogenic action that is independent of serum cholesterol.

Identification of New Hydroxy Fatty Acids and Ferulic Acid Esters in the Wood of Eucalyptus globulus

Holzforschung ◽  
2002 ◽  
Vol 56 (2) ◽  
pp. 143-149 ◽  
Author(s):  
C. S. R. Freire ◽  
A. J.D. Silvestre ◽  
C. Pascoal Neto
Keyword(s):  
Fatty Acids ◽  
Chemical Composition ◽  
Ferulic Acid ◽  
Eucalyptus Globulus ◽  
Fatty Alcohols ◽  
Hydroxy Fatty Acids ◽  
Gas Chromatography Mass Spectrometry ◽  
Published Data ◽  
First Time ◽  
Acid Esters

Summary The chemical composition of the dichloromethane extract of Eucalyptus globulus wood cultivated in Portugal was studied by gas chromatography-mass spectrometry, prior to and after alkaline hydrolysis. In addition to previously identified lipophilic extractives, 22 free or esterified compounds (14 fatty acids, 2 fatty alcohols and 6 aromatic compounds) were identified for the first time in E. globulus wood. One of these, ferulic acid, was esterified with three different fatty alcohols and with two α-hydroxyfatty acids. Some of the newly identified compounds, particularly the a-hydroxy-fatty acids are responsible for recently reported pitch problems during pulp production in a Portuguese mill. The differences found in the E. globulus chemical composition, when compared with published data, are expected to be related to variations in the location of growth and genetic factors.

scholarly journals Bioactive Compounds in Salicornia patula Duval-Jouve: A Mediterranean Edible Euhalophyte

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 410
Author(s):  
Irene Sánchez-Gavilán ◽  
Esteban Ramírez ◽  
Vicenta de la Fuente
Keyword(s):  
Fatty Acids ◽  
Bioactive Compounds ◽  
Mediterranean Area ◽  
Biological Properties ◽  
Total Phenolic ◽  
Tinto River ◽  
New Findings ◽  
High Concentrations ◽  
Salicornia Patula ◽  
First Time

Many halophytes have great nutritional and functional potential, providing chemical compounds with biological properties. Salicornia patula Duval-Jouve is a common euhalophyte from saline Mediterranean territories (Spain, Portugal, France, and Italy). In the present work we quantified for the first time the bioactive compounds in S. patula (total phenolic compounds and fatty acids), from Iberian Peninsula localities: littoral-coastal Tinto River basin areas (southwest Spain, the Huelva province), and mainland continental territories (northwest and central Spain, the Valladolid and Madrid provinces). Five phenolic acids including caffeic, coumaric, veratric, salicylic, and transcinnamic have been found with differences between mainland and coastal saltmarshes. S. patula contain four flavonoids: quercetin-3-O-rutinoside, kaempferol/luteolin, apigenin 7-glucoside, and pelargonidin-3-O-rutinoside. These last two glycosylated compounds are described for the first time in this genus of Chenopodiaceae. The fatty acid profile described in S. patula stems contains palmitic, oleic, and linoleic acids in high concentrations, while stearic and long-chain fatty acids were detected in low amounts. These new findings confirm that S. patula is a valuable source of bioactive compounds from Mediterranean area.

Fatty acyl chain structure, orientational order, and the lipid phase transition in Acholeplasma laidlawii B membranes. A review of recent 19F nuclear magnetic resonance studies

1984 ◽  
Vol 62 (11) ◽  
pp. 1134-1150 ◽  
Author(s):  
P. M. Macdonald ◽  
B. D. Sykes ◽  
R. N. McElhaney
Keyword(s):  
Phase Transition ◽  
Fatty Acids ◽  
Nuclear Magnetic Resonance ◽  
Acyl Chain ◽  
Orientational Order ◽  
Membrane Lipid ◽  
Fatty Acyl ◽  
Fatty Acyl Chain ◽  
Lipid Phase ◽  
Lipid Phase Transition

The orientational order parameters of monofluoropalmitic acids biosynthetically incorporated into membranes of Acholeplasma laidlawii B in the presence of a large excess of a variety of structurally diverse fatty acids have been determined via 19F nuclear magnetic resonance (19F NMR) spectroscopy. It is demonstrated that these monofluoropalmitic acids are relatively nonperturbing membrane probes based upon physical (differential scanning calorimetry), biochemical (membrane lipid analysis), and biological (growth studies) criteria. 19F NMR is shown to convey the same qualitative and quantitative picture of membrane lipid order provided by 2H-NMR techniques and to be sensitive to the structural characteristics of the membrane fatty acyl chains, as well as to the lipid phase transition. Representatives of each naturally occurring class of fatty acyl chain structures, including straight-chain saturated, methyl-branched, monounsaturated, and alicyclic-ring-substituted fatty acids, were studied and the 19F-NMR order parameters were correlated with the lipid phase transitions (determined calorimetrically). The lipid phase transition was the prime determinant of overall orientational order regardless of fatty acid structure. Effects upon orientational order attributable to specific structural substituents were discernible, but were secondary to the effects of the lipid phase transition. In the gel state, relative overall order was directly proportional to the temperature of the particular lipid phase transition. Not only the overall order, but also the order profile across the membrane was sensitive to the presence of particular structural substituents. In particular, in the gel state specific fatty acyl structures demonstrated a characteristic disordering effect in the membrane order profile. These various observations can be merged to provide a unified picture of the manner in which fatty acyl chain chemistry modulates the physical state of membrane lipids.

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