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Basic Science Aspects

MECHANISMS OF INCREASED SURVIVAL AFTER LIPOPOLYSACCHARIDE-INDUCED ENDOTOXIC SHOCK IN MICE CONSUMING OLIVE OIL-ENRICHED DIET

Leite, Milane S*; Pacheco, Patrícia; Gomes, Rachel N; Guedes, Alexandre T; Castro-Faria-Neto, Hugo C; Bozza, Patrícia T; Koatz, Vera Lúcia G*

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doi: 10.1097/01.shk.0000148072.12094.77
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Abstract

INTRODUCTION

Sepsis is a major challenge in medicine. It is a common and frequently fatal condition, despite the use of specific antibiotics, aggressive operative intervention, nutritional support, and life support therapies. The incidence of sepsis is still increasing, with mortality rates between 30% and 70% (1). There is now consensus that sepsis is accompanied by the inability to properly regulate the inflammatory response. Therefore, more efficient strategies to modulate the inflammation in sepsis are needed (2-4).

Bacterial sepsis and septic shock result from the overproduction of inflammatory mediators as a consequence of the interaction between the host immune system and the bacteria or bacterial wall components. One of the most known and studied of these pathogen-derived molecules is lipopolysaccharide (LPS), the main glycolipid component of the outer membrane of gram-negative bacteria. Recognition of LPS by host cells initiates an inflammatory reaction that can reproduce many features of the gram-negative infection and, for this reason, LPS is widely used as an inducer of immune and inflammatory responses (5).

The inflammatory and immune responses may be modified by dietary lipids (6,7). An epidemiological study developed with Greenland Eskimos revealed a low incidence of inflammatory and autoimmune diseases associated with diets containing fish oil, rich in n-3 fatty acids (8). Similarly, a low incidence of inflammatory and coronary heart diseases has been observed among people using the Mediterranean diet in which the primary lipid source is olive oil rich in n-9 fatty acids (9). Moreover, attempts to improve the clinical course of critically ill patients through the modulation of dietary fatty acids showed encouraging results (7).

Fatty acids are important as sources of energy, structural components of membranes, signaling molecules, and precursors of eicosanoids. The mediators derived from polyunsaturated fatty acids released from membrane phospholipids seem to modulate immune responses and regulate the production of cytokines during inflammatory processes (6,7,10-12). Of interest, dietary fatty acids have been demonstrated to modify the composition of cellular lipid domains (6). Accumulating evidence points to an important role of lipid domains, including lipid rafts and caveolae from plasma membrane and from intracellular lipid-rich domains, such as lipid bodies (LB), in cellular signaling and innate immunity (6,13). Leukocyte LB function as an intracellular store of localization of arachidonic acid and of enzymes related to eicosanoid synthesis, including mitogen-activated protein kinase, phospholipase A2, cyclooxygenase, and lipooxygenase (14-18). Recently, we demonstrated that LB formed in leukocytes after LPS stimulation are intracellular sites for paracrine eicosanoid synthesis, increasing in leukocytes from patients with sepsis in comparison with healthy subjects (19). LB are rapidly inducible and can be modulated by exogenous fatty acid administration. Unsaturated fatty acids such as arachidonic acid (20:4n-6) stimulate LB formation in a dose-dependent manner, whereas LB are not induced in the presence of saturated fatty acids, indicating that LB formation depends on the number of double bonds in the fatty acid (14-16).

In the present study, we examined whether diets of different fatty acid composition could interfere with the inflammatory process observed during LPS-induced shock.

MATERIALS AND METHODS

Materials

LPS from Escherichia coli (serotype 0111:B4) was obtained from Sigma (St. Louis, MO). Osmium tetroxide (OsO4) was obtained from Electron Microscopy Science (Fort Washington, PA).

Animals and diets

Female C57Bl/6J mice weighing 20 g were obtained from FIOCRUZ (Rio de Janeiro, Brazil). Mice were housed in a room at 25°C, with an alternating light/dark cycle of 12 h and free access to pelleted diet and water. All manipulations with animals were in accordance to guidelines of the Council for International Organization of Medical Sciences and the Brazilian College for Animal Experimentation. The experiments described in this work received prior approval from the Oswaldo Cruz Foundation Animal Welfare Committee. The diets used included a commercial chow (CC) for laboratory rodents (Purina, São Paulo, Brazil) and four experimental diets containing 7% (w/w) of commercial canola oil (CO), sesame oil (SeO), soybean oil (SO), or virgin olive oil (OO). These four experimental diets were prepared according to the American Institute of Nutrition (AIN-93) for laboratory rodent diets, containing vitamin E and other antioxidant compounds (20). These oils were chosen according to the content of oleic, linoleic, and linolenic acids. All diets were stored at 4°C before use and were provided fresh to the animals every 2 days. Mice were killed between 8:30 and 9:30 a.m. under CO2 atmosphere.

Fatty acid composition of the oils and diets used

The oils used in chow preparation were analyzed by capillary gas chromatography for detection of fatty acids. Oleic acid (18:1n-9) is the predominant fatty acid in CO and OO. SeO and SO are rich in linoleic acid (18:2n-6). These data are similar to those described in the literature for all oils used (21), showing no loss of fatty acid content during diet preparation (70°C for 12 h) and that the 18:2n-6/18:3n-3 ratio was not altered. Fatty acid composition of each diet was analyzed by capillary gas chromatography. Briefly, all samples were directly transesterified (22) and the resulting fatty acid methyl esters in hexane were injected into a gas chromatograph (GC-14B; Shimadzu, Columbia, MD) with split injection. Separation was achieved with an Omegawax-320 capillary column (Supelco, Bellefonte, PA) using temperature gradient elution, and fatty acids were identified after comparison of retention times of analytes with those of certified standards (Sigma). Fatty acid contents are expressed as weight percentages (wt %) of total fatty acids. Table 1 summarizes the data obtained.

Table 1
Table 1:
Fatty-acid composition of the diets used.

Endotoxic shock and peritoneal lavage

Mice were fed with different diets for 6 weeks. After this period, endotoxic shock was induced in mice with an intraperitoneal injection of LPS (400 μg/cavity) to a final volume of 200 μL. Control animals received sterile saline. Ninety minutes or 6 h after injection, mice were killed and the peritoneal cavity was opened and rinsed with 5 mL of cold saline. Total leukocyte counts were performed in a Neubauer chamber, and differential leukocyte counts were performed on a Cytospin 3 (Shandon, Pittsburgh, PA) spots stained with Diff-Qwick (Shandon). Survival of mice fed with CC or test diets and injected with saline or LPS was determined daily for 7 days in separate groups of 10 animals for each diet condition.

LB staining and enumeration

LB were evaluated in leukocytes (106 cells/mL) collected in peritoneal fluid 90 min or 6 h after saline or LPS injection. Leukocytes on cytospin spots (while still moist) were fixed in 3.7% formaldehyde prepared in Ca2+/Mg2+-free Hanks' balanced salt solution (HBSS, pH 7.4), rinsed in 0.1 M cacodylate buffer (pH 7.4), stained with 1.5% OsO4 for 30 min, rinsed in distilled water, immersed in 1.0% thiocarbohydrazide for 5 min, rinsed in 0.1 M cacodylate buffer, restained in 1.5% OsO4 for 5 min, rinsed in distilled water, and then dried and mounted. The morphology of fixed cells was observed, and LB were enumerated by light microscopy with a 100× objective lens in 50 consecutively scanned leukocytes.

Leukotriene B4 (LTB4) and prostaglandin E2 (PGE2) assays

Lipid mediators were measured directly in the supernatant from cell-free peritoneal lavage obtained 90 min after saline or LPS injection or 6 h after preincubation of peritoneal leukocytes (106 cells/mL) in HBSS containing Ca2+ and Mg2+ and stimulation with 0.5 μM A23187 for 15 min. Reactions were stopped on ice, and samples were centrifuged at 500g for 10 min at 4°C. LTB4 and PGE2 were assayed in the cell-free supernatant by enzyme-linked immunoassay (EIA) according to the manufacturer's instructions (Cayman Chemical, Ann Arbor, MI).

Cytokine analysis

TNF-α from plasma and IL-6, IL-10, and MCP-1 from peritoneal fluid collected 90 min after saline or LPS injection were measured by enzyme-linked immunoabsorbant assay (ELISA) according to the manufacturer's instructions (R&D Systems, Minneapolis, MN).

Statistical analysis

Results are expressed as means ± SEM and were analyzed by means of one-way analysis of variance (ANOVA) followed by the Bonferroni student's t test (Sigma Stat, v 1.0) with the level of significance set at P ≤ 0.05. Survival curves were generated with Prism computer software (GraphPad, San Diego, CA), and comparisons between curves were made by the Mantel-Cox log-rank test.

RESULTS

Body weight and food intake in mice fed with different diets

The intake of CC or the four tested diets led to identical gains in body weight (Fig. 1A). The food intake was similar for each of the four test diets (Fig. 1B), and was lower than in mice fed with CC. Energy consumption was also lower for the test diets. This may be related to the composition of CC that stimulates mice to increase food intake.

FIG. 1
FIG. 1:
Body weight (A) and food intake (B) of mice fed with different diets. Groups of six mice were evaluated for 6 weeks. Mice were fed with CC or with chow containing CO, SeO SO, or OO. Values represent the means ± SEM. Values in a column not sharing a common superscript letter are significantly different (P < 0.05; one-way ANOVA).

Survival rate after LPS-induced endotoxic shock

After 6 weeks on CC or a test diet, animals received an i.p. injection of saline or 400 μg of LPS in the peritoneal cavity. Six hours after LPS, mice clearly displayed the symptoms of endotoxic shock, such as decreased motor activities, ruffled fur, diarrhea, and ocular exudates, as described in Reference 23. Figure 2 shows that 24 h after LPS, 80% of mice fed with SO died. In 48 h, 70% to 80% of mice fed with CC, SeO, or CO died. However, mice fed with a diet enriched with OO were resistant to endotoxic shock, with a 60% survival rate at 168 h. Saline-injected mice had 100% survival rate for the time evaluated (data not shown).

FIG. 2
FIG. 2:
Survival rate in mice after LPS-induced shock. Groups of 10 mice fed with CC or with chow containing CO, SeO, SO, or OO were injected i.p. with saline or 400 μg of LPS/cavity. An asterisk indicates a statistically significant difference compared with other groups.

Cytokine levels in LPS-induced shock

To investigate the effect of diets on the cytokine profile, IL-6, IL-10, and MCP-1 levels in peritoneal lavage and TNF-α levels in plasma were evaluated 90 min after i.p. injection of saline or LPS (400 μg). As shown in Figure 3A, LPS induced an increase in IL-6 levels with all diets used. Although IL-6 levels appeared to be lower in CO- and OO-fed mice, the differences were not significant. LPS also increased IL-10 concentrations in relation to saline-injected mice, regardless of diet used (Fig. 3B). In contrast, Figure 3C shows that the increment in MCP-1 concentrations observed after the endotoxic shock for CC, CO, SeO, and SO diets almost disappeared in OO-fed mice. In plasma, LPS induced significantly higher concentrations of TNF-α in mice fed with CC, SeO, or SO than in mice fed with CO or OO (Fig. 3D).

FIG. 3
FIG. 3:
Cytokine levels 90 min after LPS-induced shock. Groups of 10 mice fed with CC or with chow containing CO, SeO, SO, or OO were injected i.p. with saline (control) or 400 μg of LPS/cavity. IL-6 (A), IL-10 (B), and MCP-1 (C) were evaluated in peritoneal fluid, and TNF-α (D) was evaluated in plasma by ELISA. Data are presented as means ± SEM. Values not sharing a common superscript letter are significantly different compared with the other groups that received LPS (P < 0.05; one-way ANOVA).

Lipid mediators 90 min after LPS-induced shock

The effects of the different dietary fatty acids on LB formation and on lipid mediators were analyzed 90 min after LPS-induced shock. As shown in Figure 4A, there is an increase in the number of LB present in neutrophils after LPS injection in mice fed with CC, CO, SeO, and SO in relation to saline-injected mice. The increase in LB was not observed in mice fed with an OO-enriched diet. Figure 4 shows that PGE2 (Fig. 4B) and LTB4 (Fig. 4C) concentrations increased after LPS injection, but were significantly lower in mice fed with OO than in mice fed with the other diets.

FIG. 4
FIG. 4:
LB in neutrophils and PGE2 and LTB4 in peritoneal lavage 90 min after LPS-induced shock. Groups of six mice fed with CC or with chow containing CO, SeO, SO, or OO were injected i.p. with saline (control) or 400 μg of LPS/cavity. The number of LB in neutrophils (A) was evaluated, and PGE2 (B) and LTB4 (C) were measured by EIA in the supernatant from peritoneal lavages as described in “Materials and Methods.” Data are presented as means ± SEM. Values not sharing a common superscript letter are significantly different (P < 0.05; one-way ANOVA).

Neutrophil influx in LPS-induced shock

To investigate whether diet could modify neutrophil influx, a hallmark of acute inflammatory processes, cells were counted in peritoneal lavage 90 min after endotoxic shock. As shown in Figure 5, LPS induced an important influx of neutrophils into the peritoneal cavity, and this was significantly lower in mice fed with OO than for the other diets. Similar results were obtained when neutrophil numbers were evaluated 6 h after endotoxic shock (data not shown). Mononuclear leukocytes in peritoneal lavage were also counted, and no difference was found among dietary groups (data not shown).

FIG. 5
FIG. 5:
Neutrophil migration into the peritoneal cavity 90 min after LPS-induced shock. Groups of six mice fed with CC or with chow containing CO, SeO, SO, or OO were injected i.p. with saline or 400 μg of LPS/cavity. Neutrophils were counted in the peritoneal lavage as described in “Materials and Methods.” Data are presented as means ± SEM. Values not sharing a common superscript letter are significantly different (P < 0.05; one-way ANOVA).

Lipid mediators 6 h after LPS-induced shock

The production of lipid mediators by cells recovered from the peritoneal cavity 6 h after LPS-induced shock was also investigated. As shown in Figure 6, and confirming our previous results (17), in peritoneal leukocytes primed by a previous contact with LPS, there was a significant increase in the number of LB. Interestingly, the increase in LB numbers was significantly reduced in leukocytes obtained from animals fed with OO. Stimulation of peritoneal cells in vitro with 0.5 μM of the calcium ionophore, A23187, induced a marked production of PGE2 and LTB4 in CC-, CO-, SeO-, and SO-fed mice in relation to saline-injected mice. In contrast, in mice fed with OO, there was a significant reduction of PGE2 and LTB4 production.

FIG. 6
FIG. 6:
Effect of dietary fatty acid on LPS-induced LB formation and priming for lipid mediator production. This legend is similar to Figure 4. LB formation (A) was evaluated in leukocytes obtained from peritoneal lavage 6 h after LPS-induced shock. Leukocytes (106 cells/mL) obtained from the peritoneal cavity 6 h after saline (control) or LPS stimulation in vivo were restimulated in vitro with A23187 (0.5 μM) and PGE2 (B) and LTB4 (C) generation were evaluated in the cell-free supernatant. Data are presented as means ± SEM. Values not sharing a common superscript letter are significantly different (P < 0.05; one-way ANOVA).

DISCUSSION

This study shows for the first time that mice fed with OO have improved survival to endotoxic shock and that the protective mechanism may involve modulation of LB formation and decreased production of inflammatory mediators.

The severity of sepsis can be influenced by the nutritional status of humans and animals. The beneficial effect of consuming OO on endotoxic shock observed in the present study was also detected in mice fed with diets containing SeO, followed by cecal ligation and puncture (CLP), and in guinea pigs fed with fish oil, followed by endotoxin injection (24,25). Such an increase in survival may be explained by the ability of dietary lipids to modulate the production of cytokines and lipid mediators in response to bacterial endotoxin (7,11). Consumption of OO over 6 weeks led to lower levels of IL-6 and TNF-α, similar to what was observed with CO, suggesting that diets containing lipids rich in oleic acid (n-9) may modulate synthesis of proinflammatory cytokines induced by LPS. However, only in mice fed with OO was MCP-1 production almost completely blocked, suggesting that other components of this oil may also exert an important role in modulating cytokines involved in the inflammatory response. Similarly, LB formation was reduced in mice fed with OO, and this was accompanied by a reduction in the synthesis of PGE2 and total blockage of LTB4 production.

Extra virgin and virgin OO are unique among dietary lipids in that they are obtained from seeds without any extraction by solvents; thus, the chemical composition of all natural components in the seeds is retained (26). It has been demonstrated that minor components of OO, such as oleuropein, tyrosol, and other phenolic compounds, have anti-eicosanoid and antioxidant effects in leukocytes (26,27). Administration of OO to healthy volunteers over 3 weeks provided effective protection against low-density lipoprotein oxidation, decreasing oxidative stress markers, and increasing high-density lipoprotein cholesterol levels in the peripheral blood (28).

Curiously, the synthesis of LTB4 and MCP-1 triggered by the endotoxic shock was almost completely abolished with the consumption of OO. This was accompanied by a significant decrease in neutrophil influx into the peritoneal cavity and a decrease in the formation of LB in leukocytes. LB are nonmembrane-bound lipid-rich cytoplasmic inclusions that characteristically increase in number during inflammatory conditions, including adult respiratory distress syndrome and sepsis (19,29). Previously, it has been demonstrated that LB in leukocytes are compartmentalization sites for arachidonic acid, phospholipase A2, and eicosanoid-forming enzymes (14-18), and they are involved in the enhanced production of prostaglandins and leukotrienes (15-19,30). These findings are consistent with our present results showing that an increase in LB numbers correlates with increased LTB4 and PGE2 release by these cells after activation with submaximal concentrations of A23187. Conversely, agents that inhibited LB formation in vitro inhibited the priming response for enhanced eicosanoid release (15,16), which may explain the results obtained with the consumption of dietary virgin oil. LTB4 is a potent chemotactic agent for neutrophils and it has been shown to play an important role in the accumulation of neutrophils in experimental models of sepsis (31,32). MCP-1 stimulates the production of LTB4 from peritoneal macrophages in vitro and, in turn, a specific LTB4 receptor antagonist inhibited CLP-induced neutrophil and macrophage influx that was accompanied by a reduced level of MCP-1 in peritoneum (32). Moreover, the lack of MCP-1 in knockout mice abolished leukocyte accumulation and reduced the level of LTB4 (33). Elevated levels of MCP-1 have been detected in plasma of patients with peritonitis (34), as well as after administration of endotoxin in animals or human volunteers (35,36). Elevated MCP-1 levels observed in mice consuming diets containing CO, SeO, or SO may serve as an indirect mediator to attract neutrophils via the production of LTB4 after LPS, suggesting a cross-talk between these mediators during LPS-endotoxic shock, as demonstrated before for septic peritonitis (31) and pleurisy (33).

Analysis of these data leads us to speculate that the beneficial effect of dietary virgin OO against endotoxic shock may be associated with inhibition of LB formation and MCP-1 production with an impact on the generation of LTB4 and on recruitment of activated leukocytes. There is also a possibility that after 6 weeks, consumption of virgin OO led to a modification of cellular lipid domains such as in the composition of lipid rafts, or promoted the production of 5-series of leukotrienes, which are 10- to 100-fold less potent than those from 4-series in developing the inflammatory process (7,37). These and other possibilities to explain the beneficial effect of virgin OO on septic shock are now under investigation.

ACKNOWLEDGMENT

The authors thank Dr. Martha M. Sorenson for her careful revision of this manuscript.

REFERENCES

1. Angus DC, Linde-Zwirble WT, Lidicker J, Clermont G, Carcillo J, Pinsky MR: Epidemiology of severe sepsis in the United States: analysis of incidence, outcome, and associated cost of care. Crit Care Med 29:1303-1310, 2001.
2. Baue AE, Durham R, Faist E: Systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome (MODS), multiple organ failure (MOF): are we winning the battle? Shock 10:79-89, 1998.
3. Moine P, Abraham E: Immunomodulation and sepsis: impact of the pathogen. Shock 22:297-308, 2004.
4. Wu A, Hinds CJ, Thiemermann C: High-density lipoproteins in sepsis and septic shock: mechanism, actions, and therapeutic applications. Shock 21:210-221, 2004.
5. Van Amersfoort ES, Van Berkel TJ: Kuiper receptors, mediators, and mechanisms involved in bacterial sepsis and septic shock. J Clin Microbiol Rev 16:379-414, 2003.
6. Yaqoob P: Fatty acids as gatekeepers of immune cell regulation. Trends Immunol 24:639-645, 2003.
7. Calder PC: Long-chain n-3 fatty acids and inflammation: potential application in surgical and trauma patients. Braz J Med Biol Res 36:433-446, 2003.
8. Kromann N, Green A: Epidemiological studies in the Upernavik district, Greenland. Incidence of some chronic diseases 1950-1974. Acta Med Scand 208:401-406, 1980.
9. Keys A: The diet and fifteen-year death rate in the seven countries study. Am J Epidemiol 124:903-915, 1986.
10. Gonçalves-de-Moraes VL, Vargaftig BB, Lefort J, Meager A, Chignard M: Effect of cyclooxygenase inhibitors and modulators of cyclic AMP formation on lipopolysaccharide-induced neutrophil infiltration in mouse lung. Br J Pharmacol 117:1792-1796, 1996.
11. Sadeghi S, Wallace FA, Calder PC: Dietary lipids modify the cytokine response to bacterial lipopolysaccharide in mice. Immunology 96:404-410, 1999.
12. Wallace FA, Miles EA, Evans C, Stock TE, Yaqoob P, Calder PC: Dietary fatty acids influence the production of Th1- but not Th2-type cytokines. J Leukocyte Biol 69:449-457, 2001.
13. Anderson RG, Jacobson K: A role for lipid shells in targeting proteins to caveolae, rafts, and other lipid domains. Science 296:1821-1825, 2002.
14. Weller PF, Ryeom SW, Picard ST, Ackerman SJ, Dvorak AM: Cytoplasmic lipid bodies of neutrophils: formation induced by cis-unsaturated fatty acids and mediated by protein kinase C. J Cell Biol 113:137-146, 1991.
15. Bozza PT, Payne JL, Morham SG, Langenbach R, Smithies O, Weller PF: Leukocyte lipid body formation and eicosanoid generation: cyclooxygenase-independent inhibition by aspirin. Proc Natl Acad Sci USA 93:11091-11096, 1996.
16. Bozza PT, Payne JL, Goulet JL, Weller PF: Mechanisms of platelet-activating factor-induced lipid body formation: requisite roles for 5-lipoxigenase and de novo protein synthesis in the compartmentalization of neutrophil lipids. J Exp Med 183:1515-1520, 1996.
17. Yu W, Bozza PT, Tzizik DM, Gray JP, Cassara J, Dvorak AM, Weller PF: Co-compartmentalization of MAP kinases and cytosolic phospholipase A2 at cytoplasmic arachidonate-rich lipid bodies. Am J Pathol 152:759-769, 1998.
18. Bozza PT, Yu W, Penrose JF, Morgan ES, Dvorak AM, Weller PF: Eosinophil lipid bodies: specific, inducible intracellular sites for enhanced eicosanoid formation. J Exp Med 186:909-920, 1997.
19. Pacheco P, Bozza FA, Gomes RN, Bozza M, Weller PF, Castro-Faria-Neto HC, Bozza PT: Lipopolysaccharide-induced leukocyte lipid body formation in vivo: innate immunity elicited intracellular loci involved in eicosanoids metabolism. J Immunol 169:6498-6506, 2002.
20. Reeves PG, Nielsen FH, Fahey GC: AIN-93 purified diets for laboratory rodents: final report of the American Institute of Nutrition Ad Hoc Writing Committee on the reformulation of the AIN-76A rodent diet. J Nutr 123: 1939-1951, 1993.
21. White JP: Fatty acids in oilseeds (vegetable oils). In Chow CK (ed.): Fatty Acids in Foods and Their Health Implications. New York: Marc Inc., 2000, pp 209-238.
22. Lepage G, Roy CC: Direct transesterification of all classes of lipids in a one-step reaction. J Lip Res 27:114-120, 1986.
23. Nemzek JA, Xiao HY, Minard AE, Bolgos GL, Remick DG: Humane endpoints in shock research. Shock 21:17-25, 2004.
24. Chavali SR, Utsunomiya T, Forse RA: Increased survival after cecal ligation and puncture in mice consuming diets enriched with sesame seed oil. Crit Care Med 29:140-143, 2001.
25. Massioli E, Leader L, Flores E, Trimbo S, Bistrian B, Blackburn G: Enhanced survival to endotoxin in guinea pigs fed IV fish oil emulsion. Lipids 23:623-625, 1988.
26. Visioli F, Galli C: Olive oil: more than just oleic acid. Am J Nutrition 72:853, 2000.
27. de la Puerta R, Ruiz Gutierrez V, Hoult JR: Inhibition of leukocyte 5-lipoxygenase by phenolics from virgin olive oil. Biochem Pharmacol 57:445-449, 1999.
28. Marrugat J, Covas MI, Fito M, Schroder H, Miro-Casas E, Gimeno E, Lopez-Sabater MC, de la Torre R, Farre M: Effects of differing phenolic content in dietary olive oils on lipids and LDL oxidation. A randomized controlled trial. Eur J Nutr 43:140-147, 2004.
29. Triggiani M, Oriente A, Seeds MC, Bass DA, Marone G, Chilton FH: Migration of human inflammatory cells into the lung results in the remodeling of arachidonic acid into a triglyceride pool. J Exp Med 182:1181-1190, 1995.
30. Bandeira-Melo C, Phoofolo M, Weller PF: Extranuclear lipid bodies, elicited by CCR3-mediated signaling pathways, are the sites of chemokine-enhanced leukotriene C4 production in eosinophils and basophils. J Biol Chem 276:22779-22787, 2001.
31. Matsukawa A, Hogaboam CM, Lukacs NW, Lincoln PM, Strieter RM, Kunkel SL: Endogenous monocyte chemoattractant protein-1 (MCP-1) protects mice in a model of acute septic peritonitis: cross-talk between MCP-1 and leukotriene B4. J Immunol 163:6148-6154, 1999.
32. Rios-Santos F, Benjamim CF, Zavery D, Ferreira SH, Cunha Fde Q: A critical role of leukotriene B4 in neutrophil migration to infectious focus in cecal ligation and puncture sepsis. Shock 19:61-65, 2003.
33. Silva AR, de Assis EF, Caiado LFC, Marathe GK, Bozza MT, McIntyre TM, Zimmerman GA, Prescott SM, Bozza PT, Castro-Faria-Neto HC: Monocyte chemoattractant protein-1 and 5-lipoxygenase products recruit leukocytes in response to platelet-activating factor-like lipids in oxidized low-density lipoprotein. J Immunol 168:4112-4120, 2002.
34. Riese J, Schoolmann S, Denzel C, Herrmann O, Hohenberger W, Haupt W: Effect of abdominal infections on peritoneal and systemic production of interleukin 6 and monocyte chemoattractant protein-1. Shock 17:361-364, 2002.
35. Jansen PM, Van Damme J, Put W, de Jong IW, Taylor FB Jr., Hack CE: Monocyte chemotactic protein 1 is released during lethal and sublethal bacteremia in baboons. J Infect Dis 171:1640-1642, 1995.
36. Sylvester I, Suffredini AF, Boujoukos AJ, Martich GD, Danner RI, Yoshimura T, Leonard EJ: Neutrophil attractant protein-1 and monocyte chemoattractant protein-1 in human serum: effects of intravenous lipopolysaccharide on free attractants, specific IgG autoantibodies and immune complexes. J Immunol 151:3292-3298, 1993.
37. Grimminger F, Whan H, Mayer K, Kiss L, Walmrath D, Seeger W: Impact of arachidonic versus eicosapentaenoic acid on exotonin-induced lung vascular leakage: relation to 4-series vs. 5-series leukotriene generation. Am J Respir Crit Care Med 155:513-519, 1997.
Keywords:

Inflammation; LPS; lipid body; dietary fatty acid; eicosanoid; cytokine

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