scholarly journals Role of an acidic compartment in synthesis of disaturated phosphatidylcholine by rat granular pneumocytes

1982 ◽  
Vol 208 (3) ◽  
pp. 651-658 ◽  
Author(s):  
Avinash Chander ◽  
Aron B. Fisher ◽  
Jerome F. Strauss
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Palmitic Acid ◽  
De Novo ◽  
Lung Surfactant ◽  
Specific Radioactivity ◽  
Intact Cells ◽  
Subcellular Compartment ◽  
Surfactant Phospholipids ◽  
Stimulation Of

A possible role for an acidic subcellular compartment in biosynthesis of lung surfactant phospholipids was evaluated with granular pneumocytes in primary culture. Incubation with chloroquine (100μm) was used to perturb this compartment. With control cells, incorporation of [9,10-3H]palmitic acid into total lipids and into total phosphatidylcholines increased linearly with time up to 4h. Total incorporation into phosphatidylcholine during a 1h incubation was 999+85pmol of [9,10-3H]palmitic acid, 458±18pmol of [1-14C]oleic acid and 252±15pmol of [U-14C]glucose per μg of phosphatidylcholine phosphorus. The cellular content of either disaturated phosphatidylcholine or total phosphatidylcholines did not change during a 2h incubation with chloroquine. In the presence of chloroquine, the specific radioactivity of [3H]palmitic acid in disaturated phosphatidylcholine increased by 40%, and that of disaturated-phosphatidylcholine fatty acids from [U-14C]glucose increased by 125%. Incorporation of [1-14C]oleic acid into phosphatidylcholine was decreased by chloroquine by 79% and 33% in the presence or absence of palmitic acid respectively. Chloroquine stimulated phospholipase activity in intact cells, and in sonicated cells at pH4.0, but not at pH8.5. The observations indicate that chloroquine stimulates synthesis of disaturated phosphatidylcholine in granular pneumocytes from fatty acids, both exogenous and synthesized de novo, which can be due to stimulation of acidic phospholipase. This stimulation of acidic phospholipase A activity by chloroquine appears to be coupled to the synthesis of disaturated phosphatidylcholine, thereby enhancing remodelling of phosphatidylcholine synthesized de novo. Our findings, therefore, implicate the involvement of an acidic subcellular compartment in the remodelling pathway of disaturated phosphatidylcholine synthesis by granular pneumocytes.

Über eine in-vivo-Methode zur Herstellung radioaktiv markierter Phosphatide mit Sojabohnen / A Method for Preparing Radioactive Labeled Phosphatides Using Soybeans in-Vivo

1971 ◽  
Vol 26 (5) ◽  
pp. 425-434 ◽  
Author(s):  
J. Hölzl ◽  
H. Wagner
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Phosphatidic Acid ◽  
Stearic Acid ◽  
Palmitic Acid ◽  
De Novo ◽  
Specific Radioactivity ◽  
De Novo Synthesis ◽  
Experimental Conditions

Germinating soybeans, when incubated for 20-30 hours under an illumination at 25°-30° temp, with labeled 32P-phosphate, 14C-acetate, 14C-glycerol and 14C-choline, radioactivity ranging from 2 to 14% is incorporated into the main phosphatides lecithin (PC), phosphatidylethanolamine (PE) and monophosphoinositide (MPI). The incorporation of 32P-phosphate in these phosphatides depending on light and temperature, increases to its maximum (3.7 mCi/1 g soybeans) almost running linear and continues further even in the absence of any further germination due to intensive exposure to radiation.14C-acetate is incorporated almost exclusively into fatty acids of the phospholipids during germination as a result of which highest specific radioactivity was seen in the stearic acid followed by oleic acid and palmitic acid. Linol- and linolenic acid under these experimental conditions are weakly or not labeled, 14C-choline is incorporated only in PC. As the PC after 14C-(methyl) -methionine-incubation does not exhibit any significant labeling, one can exclude the pathway of PC-biosynthesis through PE-methylation. The utilization of 14C-glycerol proves that the incorporation of all the compounds under consideration here is effected not by a mere exchange but by a de novo synthesis. This procedure of labeling is suitable for preparing 3H-, 14C- and 32P-PC, -PE, -MPI and phosphatidic acid (PA).

scholarly journals Species pattern of phosphatidylinositol from lung surfactant and a comparison of the species pattern of phosphatidylinositol and phosphatidylglycerol synthesized de novo in lung microsomal fractions

1988 ◽  
Vol 254 (1) ◽  
pp. 67-71 ◽  
Author(s):  
B Rüstow ◽  
Y Nakagawa ◽  
H Rabe ◽  
K Waku ◽  
D Kunze
Keyword(s):  
Lung Function ◽  
Molecular Species ◽  
De Novo ◽  
Lung Surfactant ◽  
Minor Component ◽  
Main Species ◽  
Surfactant Phospholipids ◽  
Species Pattern ◽  
A Minor

1. Phosphatidylinositol (PI) is a minor component of lung surfactant which may be able to replace the functionally important phosphatidylglycerol (PG) [Beppu, Clements & Goerke (1983) J. Appl. Physiol. 55, 496-502] without disturbing lung function. The dipalmitoyl species is one of the main species for both PI (14.4%) and PG (16.9%). Besides the C16:0--C16:0 species, the C16:0--C18:0, C16:0--C18:1, C16:0--C18:2 and C18:0--C18:1 species showed comparable proportions in the PG and PI fractions. These similarities of the species patterns and the acidic character of both phospholipids could explain why surfactant PG may be replaced by PI. 2. PI and PG were radiolabelled by incubation of microsomal fractions with [14C]glycerol 3-phosphate (Gro3P). For 11 out of 14 molecular species of PI and PG we measured comparable proportions of radioactivity. The radioactivity of these 11 species accounted together for more than 80% of the total. The addition of inositol to the incubation system decreased the incorporation in vitro of Gro3P into PG and CDP-DG (diacylglycerol) of lung microsomes (microsomal fractions), but did not change the distribution of radioactivity among the molecular species of PG. These results supported the idea that both acidic surfactant phospholipids may be synthesized de novo from a common CDP-DG pool in lung microsomes.

scholarly journals Effect of fatty acid chain length and saturation on the gastrointestinal handling and metabolic disposal of dietary fatty acids in women

1999 ◽  
Vol 81 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Amanda E. Jones ◽  
Michael Stolinski ◽  
Ruth D. Smith ◽  
Jane L. Murphy ◽  
Stephen A. Wootton
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Stearic Acid ◽  
Palmitic Acid ◽  
Chain Length ◽  
Time Course ◽  
Absorbed Dose ◽  
Dietary Fatty Acids ◽  
Fatty Acid Chain ◽  
Degree Of Unsaturation

The gastrointestinal handling and metabolic disposal of [1-13C]palmitic acid, [1-13C]stearic acid and [1-13C]oleic acid administered within a lipid–casein–glucose–sucrose emulsion were examined in normal healthy women by determining both the amount and nature of the13C label in stool and label excreted on breath as13CO2. The greatest excretion of13C label in stool was in the stearic acid trial (9.2 % of administered dose) whilst comparatively little label was observed in stool in either the palmitic acid (1.2 % of administered dose) or oleic acid (1.9 % of administered dose) trials. In both the palmitic acid and oleic acid trials, all of the label in stool was identified as being present in the form in which it was administered (i.e. [13C]palmitic acid in the palmitic acid trial and [13C]oleic acid in the oleic acid trial). In contrast, only 87 % of the label in the stool in the stearic acid trial was identified as [13C]stearic acid, the remainder was identified as [13C]palmitic acid which may reflect chain shortening of [1-13C]stearic acid within the gastrointestinal tract. Small, but statistically significant, differences were observed in the time course of recovery of13C label on breath over the initial 9 h of the study period (oleic acid = palmitic acid > stearic acid). However, when calculated over the 24 h study period, the recovery of the label as13CO2was similar in all three trials (approximately 25 % of absorbed dose). These results support the view that chain length and degree of unsaturation may influence the gastrointestinal handling and immediate metabolic disposal of these fatty acids even when presented within an emulsion.

scholarly journals Antagonism Between Saturated and Unsaturated Fatty Acids in ROS Mediated Lipotoxicity in Rat Insulin-Producing Cells

2015 ◽  
Vol 36 (3) ◽  
pp. 852-865 ◽  
Author(s):  
Wiebke Gehrmann ◽  
Wiebke Würdemann ◽  
Thomas Plötz ◽  
Anne Jörns ◽  
Sigurd Lenzen ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Palmitic Acid ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
H2o2 Production ◽  
Β Cell ◽  
Specific Expression ◽  
Insulin Producing Cells ◽  
H2o2 Formation

Background/Aims: Elevated levels of non-esterified fatty acids (NEFAs) are under suspicion to mediate β-cell dysfunction and β-cell loss in type 2 diabetes, a phenomenon known as lipotoxicity. Whereas saturated fatty acids show a strong cytotoxic effect upon insulin-producing cells, unsaturated fatty acids are not toxic and can even prevent toxicity. Experimental evidence suggests that oxidative stress mediates lipotoxicity and there is evidence that the subcellular site of ROS formation is the peroxisome. However, the interaction between unsaturated and saturated NEFAs in this process is unclear. Methods: Toxicity of rat insulin-producing cells after NEFA incubation was measured by MTT and caspase assays. NEFA induced H2O2 formation was quantified by organelle specific expression of the H2O2 specific fluorescence sensor protein HyPer. Results: The saturated NEFA palmitic acid had a significant toxic effect on the viability of rat insulin-producing cells. Unsaturated NEFAs with carbon chain lengths >14 showed, irrespective of the number of double bonds, a pronounced protection against palmitic acid induced toxicity. Palmitic acid induced H2O2 formation in the peroxisomes of insulin-producing cells. Oleic acid incubation led to lipid droplet formation, but in contrast to palmitic acid induced neither an ER stress response nor peroxisomal H2O2 generation. Furthermore, oleic acid prevented palmitic acid induced H2O2 production in the peroxisomes. Conclusion: Thus unsaturated NEFAs prevent deleterious hydrogen peroxide generation during peroxisomal β-oxidation of long-chain saturated NEFAs in rat insulin-producing cells.

scholarly journals High rates of [1-14C]acetate incorporation into the lipid of isolated spinach chloroplasts

1976 ◽  
Vol 158 (3) ◽  
pp. 593-601 ◽  
Author(s):  
P G Roughan ◽  
C R Slack ◽  
R Holland
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Palmitic Acid ◽  
Free Fatty Acids ◽  
Acid Synthesis ◽  
Polar Lipids ◽  
Acetate Incorporation ◽  
Spinach Chloroplasts ◽  
Triton X

Spinach chloroplasts, isolated by techniques yielding preparations with high O2- evolving activity, showed rates of light-dependent acetate incorporation into lipids 3-4 fold higher than any previously reported. Incorporation rates as high as 500 nmol of acetate/h per mg of chlorophyll were measured in buffered sorbitol solutions containing only NaHCO3 and [1-14C]acetate, and as high as 800 nmol/h per mg of chlorophyll when 0.13 mM-Triton X-100 was also included in the reaction media. The fatty acids synthesized were predominantly oleic (70-80% of the total fatty acid radioactivity) and palmitic (20-25%) with only minor amounts (1-5%) of linoleic acid. Linolenic acid synthesis was not detected in the system in vitro. Free fatty acids accounted for 70-90% of the radioactivity incorporated and the remainder was shared fairly evenly between 1,2-diacylglycerols and polar lipids. Oleic acid constituted 80-90% of the free fatty acids synthesized, but the diacylglycerols and polar lipids contained slightly more palmitic acid than oleic acid. Triton X-100 stimulated the synthesis of diacylglycerols 3-6 fold, but stimulated free fatty acid synthesis only 1-1.5-fold. Added glycerol 1-phosphate stimulated both the synthesis of diacylglycerols and palmitic acid relative to oleic acid, but did not increase acetate incorporation into total chloroplast lipids. CoA and ATP, when added separately, stimulated acetate incorporation into chloroplast lipids to variable extents and had no effect on the types of lipid synthesized, but when added together resulted in 34% of the incorporated acetate appearing in long-chain acyl-CoA. Pyruvate was a much less effective precursor of chloroplast fatty acids than was acetate.

scholarly journals Risk of diabetes associated with fatty acids in the de novo lipogenesis pathway is independent of insulin sensitivity and response: the Insulin Resistance Atherosclerosis Study (IRAS)

2019 ◽  
Vol 7 (1) ◽  
pp. e000691 ◽  
Author(s):  
Waqas Qureshi ◽  
Ingrid D Santaren ◽  
Anthony J Hanley ◽  
Steven M Watkins ◽  
Carlos Lorenzo ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Fatty Acids ◽  
Insulin Sensitivity ◽  
Palmitic Acid ◽  
De Novo ◽  
De Novo Lipogenesis ◽  
Diabetes Incidence ◽  
Incident Type ◽  
Insulin Resistance Atherosclerosis Study

ObjectiveTo examine the associations of fatty acids in the de novo lipogenesis (DNL) pathway, specifically myristic acid (14:0), palmitic acid (16:0),cis-palmitoleic acid (c16:1 n-7),cis-myristoleic acid (c14:1n5), stearic acid (18:0) andcis-oleic acid (c18:1 n-9), with 5-year risk of type 2 diabetes. We hypothesized that DNL fatty acids are associated with risk of type 2 diabetes independent of insulin sensitivity.Research design and methodsWe evaluated 719 (mean age 55.1±8.5 years, 44.2% men, 42.3% Caucasians) participants from the Insulin Resistance Atherosclerosis Study. Multivariable logistic regression models with and without adjustment of insulin sensitivity were used to assess prospective associations of DNL fatty acids with incident type 2 diabetes.ResultsType 2 diabetes incidence was 20.3% over 5 years. In multivariable regression models, palmitic, palmitoleic, myristic, myristoleic and oleic acids were associated with increased risk of type 2 diabetes (p<0.05). Palmitic acid had the strongest association (OR per standard unit of palmitic acid 1.46; 95% CI 1.23 to 1.76; p<0.001), which remained similar with addition of insulin sensitivity and acute insulin response (AIR) to the model (OR 1.36; 95% CI 1.09 to 1.70, p=0.01). Oleic and palmitoleic acids were also independently associated with incident type 2 diabetes. In multivariable models, ratios of fatty acids corresponding to stearoyl CoA desaturase-1 and Elovl6 enzymatic activity were significantly associated with risk of type 2 diabetes independent of insulin sensitivity and AIR.ConclusionsWe observed associations of DNL fatty acids with type 2 diabetes incidence independent of insulin sensitivity.

scholarly journals FATTY ACIDS COMPOSITION OF TOCTE (JUGLANS NEOTROPICA DIELS) WALNUT FROM ECUADOR

2018 ◽  
Vol 11 (2) ◽  
pp. 395 ◽  
Author(s):  
Vilcacundo E ◽  
Alvarez M ◽  
Silva M ◽  
Carpio C ◽  
Morales D ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Linoleic Acid ◽  
Stearic Acid ◽  
Palmitic Acid ◽  
Linolenic Acid ◽  
Lipid Content ◽  
Methyl Esters ◽  
Total Lipid Content ◽  
Fatty Acids Composition

 Objective: The aim of this study was to determine the fatty acids composition in a tocte seeds oil (Juglans neotropica Diels) sample cultivated in Ecuador.Methods: Tocte oil was obtained from tocte seeds using the cold pressing method. Fatty acids analysis was carried out using the gas chromatography method with a mass selective detector (GC/MSD) and using the database Library NIST14.L to identify the compounds.Results: Methyl esters fatty acids were identified from tocte (J. neotropica Diels) walnut using the GC–MS analytical method. The total lipid content of tocte walnuts seeds of plants cultivated in Ecuador was of 49.01% of the total lipid content on fresh weight. Fatty acids were analyzed as methyl esters on a capillary column DB-WAX 122-7062 with a good separation of palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid. The structure of methyl esters fatty acids was determined using the GC–MS. Tocte walnut presents 5.05% of palmitic acid, 2.26% of stearic acid, 19.50% of oleic acid, 65.81% of linoleic acid, and 2.79% linolenic acid of the total content of fatty acids in tocte oil. Fatty acids content reported in this study were similar to the data reported for other walnuts seeds.Conclusions: Tocte seeds are a good source of monounsaturated and polyunsaturated fatty acids. Tocte oil content oleic acid and with a good content of ɷ6 α-linoleic and ɷ3 α-linolenic. Tocte walnut can help reduce risk cardiovascular diseases in Ecuador for their good composition of fatty acids.

scholarly journals S-acylation modulates the function of the apical sodium-dependent bile acid transporter in human cells

2020 ◽  
Vol 295 (14) ◽  
pp. 4488-4497 ◽  
Author(s):  
Alexander L. Ticho ◽  
Pooja Malhotra ◽  
Christopher R. Manzella ◽  
Pradeep K. Dudeja ◽  
Seema Saksena ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Bile Acid ◽  
Palmitic Acid ◽  
Unsaturated Fatty Acids ◽  
Hek293 Cells ◽  
Metabolic Labeling ◽  
Sodium Dependent ◽  
Bile Acid Transporter ◽  
Acid Transporter

The ileal apical sodium-dependent bile acid transporter (ASBT) is crucial for the enterohepatic circulation of bile acids. ASBT function is rapidly regulated by several posttranslational modifications. One reversible posttranslational modification is S-acylation, involving the covalent attachment of fatty acids to cysteine residues in proteins. However, whether S-acylation affects ASBT function and membrane expression has not been determined. Using the acyl resin-assisted capture method, we found that the majority of ASBT (∼80%) was S-acylated in ileal brush border membrane vesicles from human organ donors, as well as in HEK293 cells stably transfected with ASBT (2BT cells). Metabolic labeling with alkyne–palmitic acid (100 μm for 15 h) also showed that ASBT is S-acylated in 2BT cells. Incubation with the acyltransferase inhibitor 2-bromopalmitate (25 μm for 15 h) significantly reduced ASBT S-acylation, function, and levels on the plasma membrane. Treatment of 2BT cells with saturated palmitic acid (100 μm for 15 h) increased ASBT function, whereas treatment with unsaturated oleic acid significantly reduced ASBT function. Metabolic labeling with alkyne–oleic acid (100 μm for 15 h) revealed that oleic acid attaches to ASBT, suggesting that unsaturated fatty acids may decrease ASBT's function via a direct covalent interaction with ASBT. We also identified Cys-314 as a potential S-acylation site. In conclusion, these results provide evidence that S-acylation is involved in the modulation of ASBT function. These findings underscore the potential for unsaturated fatty acids to reduce ASBT function, which may be useful in disorders in which bile acid toxicity is implicated.

scholarly journals Metabolic fate of oleic acid, palmitic acid and stearic acid in cultured hamster hepatocytes

1996 ◽  
Vol 316 (3) ◽  
pp. 847-852 ◽  
Author(s):  
Jennifer S. BRUCE ◽  
Andrew M. SALTER
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Stearic Acid ◽  
Palmitic Acid ◽  
Ketone Bodies ◽  
Plasma Cholesterol ◽  
Saturated Fatty Acids ◽  
Metabolic Fate ◽  
Cellular Phospholipid

Unlike other saturated fatty acids, dietary stearic acid does not appear to raise plasma cholesterol. The reason for this remains to be established, although it appears that it must be related to inherent differences in the metabolism of the fatty acid. In the present study, we have looked at the metabolism of palmitic acid and stearic acid, in comparison with oleic acid, by cultured hamster hepatocytes. Stearic acid was taken up more slowly and was poorly incorporated into both cellular and secreted triacylglycerol. Despite this, stearic acid stimulated the synthesis and secretion of triacylglycerol to the same extent as the other fatty acids. Incorporation into cellular phospholipid was lower for oleic acid than for palmitic acid and stearic acid. Desaturation of stearic acid, to monounsaturated fatty acid, was found to be greater than that of palmitic acid. Oleic acid produced from stearic acid was incorporated into both triacylglycerol and phospholipid, representing 13% and 6% respectively of the total after a 4 h incubation. Significant proportions of all of the fatty acids were oxidized, primarily to form ketone bodies, but by 8 h more oleic acid had been oxidized compared with palmitic acid and stearic acid.

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