Response of endocytosis to altered fatty acyl composition of macrophage phospholipids.

Mahoney, Eileen M.; Hamill, Anne L.; Scott, William; Cohn, Zanvil A.

doi:10.1073/pnas.74.11.4895

Cited by 140 publications

(79 citation statements)

References 15 publications

(10 reference statements)

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“…Concentrated lipid extracts were applied to columns containing 0.4 g of activated silicic acid (Silicar CC-4; Mallinckrodt). Neutral lipids and phospholipids were sequentially eluted with 10 ml of chloroform and then 10 ml of methanol (18). Fatty acid methyl esters were prepared by transesterification in methanolic HCl and analyzed by gas/liquid chromatography on 1/8 inch x 10 foot (3 mm X 305 cm) columns of 10% SP-2330 on 100/200…”

Section: Methodsmentioning

confidence: 99%

Leukotriene C promotes prostacyclin synthesis by human endothelial cells.

Cramer¹,

Pologe²,

Pawlowski³

et al. 1983

Proc. Natl. Acad. Sci. U.S.A.

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Cultured endothelial cells from human umbilical vein were labeled with [3H]arachidonic acid for 16 hr. The radiolabel was localized primarily in phospholipids (93%) and 73% was distributed equally between phosphatidylcholine and phosphatidylethanolamine. Leukotriene C (10-1,000 nM) promoted a dose-dependent release of radiolabel into the culture medium. This response was 3.3 times control values at 100 nM. The major arachidonic acid metabolite synthesized was prostacyclin, which was 33% of the total released radiolabel. Endothelial cells also released small amounts of prostaglandin F2a (6.1%), unidentified lipoxygenase products (14.8%), and unreacted arachidonic acid (33%). The 30-min time course of release was independent of the leukotriene C concentration used. Leukotriene D at similar concentrations also promoted endothelial cells to release primarily prostacyclin and unreacted arachidonic acid. The release of prostacyclin, a potent vasodilatory agent, may be an important mediator in slow reacting substance effects on the vasculature.Slow reacting substances (SRS) consist of the cysteine-containing leukotrienes (LT) C, D, and E and are derived from the lipoxygenase pathway of arachidonic acid (20:4) metabolism (1). Although the effects of LTC, LTD, and LTE show both quantitative and species differences (2, 3), they are strong smooth muscle stimulants causing bronchial (4), ileal, and uterine (5) contraction. In addition, LTC and LTD are vasoactive. Both compounds produced a transient constriction of arterioles that was followed by exudation from postcapillary venules in the hamster cheek pouch (6). Likewise in monkeys, LTC promoted a rapid, transient pulmonary and systemic hypertension followed by a more prolonged fall in blood pressure with decreased cardiac output (7). This may be due to vasodilation and increased vascular permeability (6, 8), a direct or secondary effect of SRS.To explore possible mechanisms for the vasoactive effect of SRS, human endothelial cells prelabeled with [3H]20:4 were exposed to LTC. The results of this study demonstrate that 10-8 to 10-6 M LTC promotes the release of prostacyclin, a potent vasodilatory agent. MATERIALS AND METHODSMaterials. Radiolabeled prostaglandins (PG) were purchased from New England Nuclear and included 6-keto- [5,8,9,11,12,14,15-3H(N)]PGF1,, (120-180 Ci/mmol; 1 Ci = 3.7 X 10'°Bq), [5,6,8,9,11,12,14,15-3H(N)]thromboxane B2 (100-150 Ci/mnmol), [5,6,8,11,12,14,15_3 H(N)]PGF2,,, and [5,6,8,11,12,14,]PGE2 (100-200 Ci/mmol). Radiolabeled lipoxygenase products were prepared in this laboratory from various sources as described (9,10 [5,6,8,9, 11,12,14,15-3H]20:4 ([3H]20:4) (91.2 Ci/mmol; New England Nuclear). At the end of the labeling period (16 hr), the cells were washed three times with phosphate-buffered saline, placed in medium 199 without serum, and incubated at 370C. Duplicate 50-1l aliquots of medium were removed at the indicated times for radioactivity measurements. At the end of the experiment, the medium was removed, and after washing with ...

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Section: Methodsmentioning

confidence: 99%

Leukotriene C promotes prostacyclin synthesis by human endothelial cells.

Cramer¹,

Pologe²,

Pawlowski³

et al. 1983

Proc. Natl. Acad. Sci. U.S.A.

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“…The medium was filtered, and 20 ng/mL of GM-CSF was added. This medium was used instead of DMEM/FCS plus GM-CSF during the 20-22 h incubation period prior to addition of stimuli (27,28).…”

Section: Enrichment Of Raw2647 Cells With 20:4mentioning

confidence: 99%

Lipid Profiling Reveals Arachidonate Deficiency in RAW264.7 Cells: Structural and Functional Implications

et al. 2006

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Glycerophospholipids containing arachidonic acid (20:4) serve as the precursors for an array of biologically active lipid mediators, most of which are produced by macrophages. We have applied mass spectrometry-based lipid profiling technology to evaluate the glycerophospholipid structure and composition of two macrophage populations, resident peritoneal macrophages and RAW264.7 cells, with regard to their potential for 20:4-based lipid mediator biosynthesis. Fatty acid analysis indicated that RAW264.7 cells were deficient in 20:4 (10 ( 1 mol %) compared to peritoneal macrophages (26 ( 1 mol %). Mass spectrometry of total glycerophospholipids demonstrated a marked difference in the distribution of lipid species, including reduced levels of 20:4-containing lipids, in RAW264.7 cells compared to peritoneal macrophages. Enrichment of RAW264.7 cells with 20:4 increased the fatty acid to 20 ( 1 mol %. However, the distribution of the incorporated 20:4 remained different from that of peritoneal macrophages. RAW264.7 cells pretreated with granulocyte-macrophage colony stimulating factor followed by lipopolysaccharide and interferon-γ mobilized similar quantities of 20:4 and produced similar amounts of prostaglandins as peritoneal macrophages treated with LPS alone. LPS treatment resulted in detectable changes in specific 20:4-containing glycerophospholipids in peritoneal cells, but not in RAW264.7 cells. 20:4-enriched RAW264.7 cells lost 88% of the incorporated fatty acid during the LPS incubation without additional prostaglandin synthesis. These results illustrate that large differences in glycerophospholipid composition may exist, even in closely related cell populations, and demonstrate the importance of interpreting the potential for lipid-mediator biosynthesis in the context of overall glycerophospholipid composition.

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“…[3H]thymidine was obtained from Amersham (Buckinghamshire, UK). Fatty acids were complexed to BSA according to the method of Mahoney et al (1977) and 1 mM stock solutions were stored at -20°C. Subsequent analysis of the stock solutions by gas-liquid chromatography (Hudson et al, 1993) indicated that there was no significant degradation of the fatty acids during the complexing process.…”

Section: Reagentsmentioning

confidence: 99%

Effect of eicosapentaenoic acid and other fatty acids on the growth in vitro of human pancreatic cancer cell lines

Falconer¹,

Ross²,

Fearon³

et al. 1994

Br J Cancer

131

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Summary A number of polyunsaturated fatty acids have been shown to inhibit the growth of malignant cells in vitro. To investigate whether fatty acids modify the growth of human pancreatic cancer, lauric, stearic, palmitic, oleic, linoleic, alpha-linolenic, gamma-linolenic, arachidonic, docosahexaenoic and eicosapentaenoic (EPA) acids were each incubated with the cells lines MIA PaCa-2, PANC-1 and CFPAC at concentrations ranging from 1.25 JAM to 5011M and the effect of each fatty acid on cell growth was examined. All the polyunsaturated fatty acids tested had an inhibitory effect, with EPA being the most potent (ID50 2.5 -5 gM).Monounsaturated or saturated fatty acids were not inhibitory. The action of EPA could be reversed with the anti-oxidant vitamin E acetate or with oleic acid. The cyclo-oxygenase inhibitors indomethacin and piroxicam had no effect on the action of EPA. The action of EPA appeared to be associated with the generation of lipid peroxides, although the level of lipid peroxidation did not always appear to correlate directly with the extent of cell death. The ability of certain fatty acids to inhibit significantly the growth of three human pancreatic cancer cell lines in vitro at concentrations which could be achieved in vivo suggests that administration of such fatty acids may be of therapeutic benefit in patients with pancreatic cancer.

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Response of endocytosis to altered fatty acyl composition of macrophage phospholipids.

Cited by 140 publications

References 15 publications

Leukotriene C promotes prostacyclin synthesis by human endothelial cells.

Leukotriene C promotes prostacyclin synthesis by human endothelial cells.

Lipid Profiling Reveals Arachidonate Deficiency in RAW264.7 Cells: Structural and Functional Implications

Effect of eicosapentaenoic acid and other fatty acids on the growth in vitro of human pancreatic cancer cell lines

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