interleukin-8 and 15-hydroxy-5-8-11-13-eicosatetraenoic-acid

To determine the association of polyunsaturated fatty acid (PUFA)-derived lipid mediators with progression from rheumatoid arthritis (RA)-related autoimmunity to inflammatory arthritis (IA).. We conducted a prospective cohort study using data from the Studies of the Etiology of Rheumatoid Arthritis (SERA). SERA enrolled first-degree relatives (FDRs) of individuals with RA (FDR cohort) and individuals who screened positive for RA-related autoantibodies at health fairs (screened cohort). We followed up 133 anti-cyclic citrullinated peptide 3.1 (anti-CCP3.1)-positive participants, 29 of whom developed IA. Lipid mediators selected a priori were quantified from stored plasma samples using liquid chromatography tandem mass spectrometry. We fit multivariable Cox proportional hazards models for each lipid mediator as a time-varying variable. For lipid mediators found to be significantly associated with IA, we then examined interleukin-1β (IL-1β), IL-6, IL-8, and tumor necrosis factor (TNF) as potential statistical mediators.. For every 1 natural log pg/ml increase in the circulating plasma levels of proinflammatory 5-HETE, the risk of developing IA increased by 241% (hazard ratio 2.41 [95% confidence interval 1.43-4.07]) after adjusting for age at baseline, cohort (FDR or screened), and shared epitope status. The models examining 15-HETE and 17-HDHA had the same trend but did not reach significance. We did not find evidence that the association between 5-HETE and IA risk was influenced by the proinflammatory cytokines tested.. In a prospective cohort of anti-CCP-positive individuals, higher levels of 5-HETE, an important precursor to proinflammatory leukotrienes, is associated with subsequent IA. Our findings highlight the potential significance of these PUFA metabolites in pre-RA populations.

Topics: Adult; Aged; Anti-Citrullinated Protein Antibodies; Arthritis, Rheumatoid; Autoimmunity; Cohort Studies; Disease Progression; Docosahexaenoic Acids; Family; Fatty Acids, Unsaturated; Female; Humans; Hydroxyeicosatetraenoic Acids; Incidence; Interleukin-1beta; Interleukin-6; Interleukin-8; Male; Mediation Analysis; Middle Aged; Multivariate Analysis; Proportional Hazards Models; Prospective Studies; Tumor Necrosis Factor-alpha

To understand the molecular basis underlying 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE)-induced angiogenesis, we have studied the role of the Janus kinase-signal transducer and activator of transcription (Jak-STAT) signaling. The 15(S)-HETE stimulated tyrosine phosphorylation of Jak2 in a time-dependent manner in human retinal microvascular endothelial cells (HRMVECs). Inhibition of Jak2 activation via adenovirus-mediated expression of its dominant-negative mutant attenuated 15(S)-HETE-induced HRMVEC migration and tube formation and Matrigel plug angiogenesis. Similarly, 15(S)-HETE activated tyrosine phosphorylation of STAT-5B in a time-dependent manner. Dominant-negative mutant-mediated interference of STAT-5B activation suppressed 15(S)-HETE-induced HRMVEC migration and tube formation and Matrigel plug angiogenesis. The 15(S)-HETE induced interleukin-8 (IL-8) expression in Jak2-STAT-5B-dependent manner in HRMVECs. In addition, neutralizing anti-IL-8 antibodies reduced 15(S)-HETE-induced HRMVEC migration and tube formation and Matrigel plug angiogenesis. Cloning and Transfac analysis of IL-8 promoter revealed the presence of 1 putative STAT-binding sequence at -476 nt, and electrophoretic mobility shift assay and chromatin immunoprecipitation analysis showed the binding of STAT-5B to this site in response to 15(S)-HETE. Mutational analysis showed that STAT binding site is essential for 15(S)-HETE-induced IL-8 promoter activity. Together, these observations suggest that 15(S)-HETE-induced angiogenesis requires Jak2-STAT-5B-dependent expression of IL-8.

Topics: Base Sequence; Cell Line; Cell Movement; Gene Expression Regulation; Genes, Reporter; Humans; Hydroxyeicosatetraenoic Acids; Interleukin-8; Janus Kinase 2; Molecular Sequence Data; Neovascularization, Physiologic; STAT5 Transcription Factor

The ligand activated nuclear hormone receptor peroxisome proliferator-activated receptor gamma (PPARgamma) induces transcriptional repression of pro-inflammatory factors. Activation of PPARgamma is followed by amelioration of colitis in animal models of inflammatory bowel disease (IBD). A reduced expression of PPARgamma was found in epithelial cells of patients with ulcerative colitis. The eicosanoids 13-HODE and 15-HETE are products of 12/15-lipoxygenase (LOX) and endogenous ligands for PPARgamma. Dehydrogenation of 13-HODE by 13-HODE dehydrogenase results in formation of the 13-Oxo-ODE. Highest activity of 13-HODE dehydrogenase is found in colonic epithelial cells (CECs). We therefore investigated whether 13-Oxo-ODE is a new endogenous ligand of PPARgamma in CECs.. LOX activity and 13-HODE dehydrogenase in CECs were investigated after stimulation with arachidonic or linoleic acid. LOX metabolites were identified by RP-18 reversed-phase HPLC. Binding of (14)C-labelled 13-Oxo-ODE was demonstrated using a His-tagged PPARgamma.. Stimulation of HT-29 and primary CECs homogenates with and without Ca-ionophor was followed by the formation of high amounts of the linoleic acid metabolite 13-Oxo-ODE (155 and 85 ng/ml). The decrease of IL-8 secretion from IEC was more pronounced after pre-incubation with 13-Oxo-ODE compared to the PPARgamma agonist troglitazone and higher as with the known PPARgamma ligands 13-HODE and 15-HETE. Binding assays with (14)C-labelled 13-Oxo-ODE clearly demonstrated a direct interaction.. High amounts of 13-Oxo-ODE can be induced in CECs by stimulation of linoleic acid metabolism. 13-Oxo-ODE binds to PPARgamma and has anti-inflammatory effects. 13-HODE dehydrogenase might be a therapeutic target in IBD.

Topics: Animals; Arachidonic Acid; Blotting, Western; Carbon Radioisotopes; Cattle; Chromatography, High Pressure Liquid; Colon; Epithelial Cells; HT29 Cells; Humans; Hydroxyeicosatetraenoic Acids; Immunoprecipitation; Interleukin-8; Ligands; Linoleic Acid; Linoleic Acids; Linolenic Acids; Molecular Structure; PPAR gamma; Protein Binding; Reverse Transcriptase Polymerase Chain Reaction; Spectrometry, Mass, Electrospray Ionization; Transfection

Epithelial cells actively participate in inflammatory airway disease by liberating mediators such as arachidonate metabolites and cytokines. Inhibition of phosphodiesterases (PDEs) may be a useful anti-inflammatory approach. The PDE isoenzyme pattern and the effects of PDE inhibition on mediator generation were analyzed in primary cultures of human and porcine airway epithelial cells (AEC) and in the bronchial epithelial cell line BEAS-2B. PDE4 and PDE5 were detected in lysates of all cell types studied. In primary cultures of human AEC, the PDE4 variants PDE4A5, PDE4C1, PDE4D2, and PDE4D3 were identified by polymerase chain reaction analysis. Evidence of the recently described PDE7 was obtained by rolipram- insensitive cyclic adenosine monophosphate (cAMP) degradation, and its presence was verified by the demonstration of PDE7 messenger RNA. Primary cultures of human airway epithelium also expressed PDE1. Enhanced epithelial cAMP levels, induced by forskolin and PDE4 inhibition, increased formation of prostaglandin E2 (PGE2), but not of interleukin (IL)-8 or 15-hydroxyeicosatetraenoic acid (15-HETE) in airway epithelial cells. Increased cyclic guanosine monophosphate levels in these cells provoked by sodium nitroprusside and the PDE5 inhibitor zaprinast reduced the PGE2 synthesis, whereas 15-HETE and IL-8 formation were unchanged. The data suggest that PDE isoenzymes are important in airway inflammation and that PDE inhibitors exert anti-inflammatory effects by acting on AEC.

Topics: Animals; Base Sequence; Bronchi; Cells, Cultured; Cyclic AMP; Cyclic GMP; Dinoprostone; DNA Primers; Epithelial Cells; Glycoproteins; Humans; Hydroxyeicosatetraenoic Acids; Interleukin-8; Isoenzymes; Reverse Transcriptase Polymerase Chain Reaction; Swine; Trachea

Bone marrow stromal cells regulate marrow haematopoiesis by secreting interleukins (IL) such as IL-8. Lipid mediators modulate IL-8 synthesis in numerous cell types. We have investigated the effects of 5 lipid mediators (PAF, PGE(2), LTB(4), 12-HETE and 15-HETE) on the spontaneous and cytokine-induced IL-8 synthesis by human bone marrow stromal cells. By using reverse-transcriptase polymerase chain reaction (RT-PCR) we demonstrate that these cells constitutively express IL-8 transcripts. By using a specific ELISA, we found that the production of IL-8 by marrow stromal cells is enhanced after stimulation with 12-HETE (1 microM) both in serum-free and serum-containing culture medium. LTB(4)(1 microM) enhances IL-8 production only in serum-supplemented medium. PAF, PGE(2)and 15-HETE (1 microM to 0.1 nM) have no effect on the spontaneous and serum-induced production of IL-8 by human bone marrow stromal cells. PGE(2)(1 microM or 10 nM) reduces marrow stromal cell IL-8 synthesis in response to IL-1alpha or TNF-alpha. In contrast, PAF, 12-HETE, 15-HETE and LTB(4)have no effect. In conclusion, various lipid mediators modulate the spontaneous, serum- or cytokine-induced IL-8 synthesis by bone marrow stromal cells, highlighting, for the first time, their potential role in the regulation of IL-8 production within the human bone marrow.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Arachidonic Acids; Bone Marrow Cells; Cells, Cultured; Dinoprostone; Gene Expression Regulation; Humans; Hydroxyeicosatetraenoic Acids; Interleukin-8; Leukotriene B4; Reverse Transcriptase Polymerase Chain Reaction; Stromal Cells; Transcription, Genetic

We examined the ability of rIL-13 to regulate rIL-l alpha induced IL-1 beta, IL-1 receptor antagonist (IL-1ra) and IL-8 production in cultured peripheral blood mononuclear cells (PBMC), endothelial cells and fibroblasts. Furthermore we examined whether rIL-13 could influence the production of the arachidonic acid products LTB4, 12-HETE and 15-HETE by PBMC. rIL-1 alpha-stimulated PBMC cultures secreted high levels of IL-1 beta and IL-8; this could be inhibited to the level of unstimulated control cells by co-incubation with rIL-13 (10 ng/ml). IL-13 induced a 3-fold increase of the IL-1ra secretion which was inhibited by rIFN-gamma. In the presence of both rIL-1 alpha and rIL-13, endothelial cells increased IL-8 secretion, whereas dermal fibroblasts remained unchanged. Of the arachidonic acid metabolites examined, the greatest change was observed in the formation of 15-HETE. In unstimulated PBMC cultures the amount of 15-HETE was less than 4 ng/10(6) cells, whereas after addition of rIL-13 we measured a formation of 139 +/- 6.2 ng/10(6) cells. The effect of rIL-13 on the 15-HETE formation in PBMC was abolished by addition of 100 U/ml rIFN-gamma. rIL-13 only induced minor changes in the LTB4 and 12-HETE formation. Compared to IL-4, IL-13 induced a similar alteration of the cytokine cascade and arachidonic acid metabolism, supporting the hypothesis that the two cytokines use a common receptor complex or signal pathway.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Animals; Anti-Inflammatory Agents, Non-Steroidal; Antigens, CD; Arachidonic Acid; Cells, Cultured; Drug Synergism; Endothelium, Vascular; Fibroblasts; Humans; Hydroxyeicosatetraenoic Acids; Interferon-gamma; Interleukin 1 Receptor Antagonist Protein; Interleukin-1; Interleukin-13; Interleukin-13 Receptor alpha1 Subunit; Interleukin-4; Interleukin-8; Leukocytes, Mononuclear; Leukotriene B4; Mice; Receptors, Interleukin; Receptors, Interleukin-13; Receptors, Interleukin-4; Recombinant Proteins; Sialoglycoproteins; Signal Transduction

We have examined the ability of interleukin-4 (IL-4), interleukin-10 (IL-10) and interleukin-1 receptor antagonist protein (IL-1ra) to regulate spontaneous interleukin-8 (IL-8) production in cultured SF mononuclear cells (SFMC) from RA. Furthermore, we examined whether IL-4, IL-10, or IL-1ra could influence the production of the arachidonic acid products leukotriene B4 (LTB4), 12-hydroxy-eicosatetraenoic acid (12-HETE) and 15-hydroxy-eicosatetraenoic acid (15-HETE). IL-4 induced a maximal suppression of 75% in the IL-8 secretion in SFMC from 10.0 ng/ml down to 2.5 ng/ml after 24 h and from 17.2 ng/ml to 4.2 ng/ml after 72 h of culture. IL-10 induced a 55% inhibition of the IL-8 secretion at 24 h and a 40% inhibition at 72 h. IL-1ra did not change the spontaneous IL-8 secretion from rheumatoid SFMC. We also examined, whether addition of IL-4, IL-10 or IL-1ra was able to modulate formation of the arachidonic acid products LTB4, 12-HETE and 15-HETE in cultured SF cells, stimulated with the calcium ionophore A23187. 15-HETE was not detected in untreated cultures, nor in IL-10 or IL-1ra treated cultures. IL-4, however, stimulated the formation of the anti-inflammatory mediator; 15-HETE (23 ng/10(6) cells). These results suggest that IL-4 or IL-10, could have beneficial anti-inflammatory effects in RA.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Arthritis, Rheumatoid; Humans; Hydroxyeicosatetraenoic Acids; Interleukin 1 Receptor Antagonist Protein; Interleukin-10; Interleukin-4; Interleukin-8; Leukotriene B4; Sialoglycoproteins; Synovial Fluid

Interleukin-8 (IL-8), is a potent activator of polymorphonuclear leukocyte (PMN) functions including chemotaxis, superoxide anion production, and enzyme release and it is also chemotactic for lymphocytes. Additionally, it has recently been shown that IL-8 stimulates the formation of 5-lipoxygenase (LO) products of arachidonic acid (AA) by human PMNs. The purpose of the present study was to determine whether IL-8 also might affect the formation of 15-LO products from AA. Purified PMNs in phosphate buffered saline were preincubated with and without exogenous AA (10(-5)-10(-4) M) for 10 min. Then IL-8 was added in biologically relevant concentrations ranging from 0.1 to 100 ng/ml and incubation was carried out for 5 min at 37 degrees C. Lipids were then extracted from supernatants, and eicosanoids were determined by quantitative RP-HPLC. Compared with unstimulated cells, IL-8 resulted in a dose dependent increase in both LTB4 and 15-HETE (up to 125% and 40% at 100 ng/ml, respectively). This increase in eicosanoid formation required the presence of exogenous AA. These results indicate that IL-8 is both a potent stimulator of 5-LO activity and of 15-LO activity. LTB4 can induce both inflammation and contribute to hyperproliferation in the skin. 15-HETE in contrast has the ability to inhibit the effects induced by LTB4. Because IL-8 is able to stimulate both LTB4 and 15-HETE formation, the effect of IL-8 as a putative regulator of inflammatory processes may be dependent on the relative stimulation of 5-LO and 15-LO.

Topics: Chromatography, High Pressure Liquid; Humans; Hydroxyeicosatetraenoic Acids; In Vitro Techniques; Interleukin-8; Lipids; Neutrophils

Extreme sensitivity of airways to multiple stimuli characterizes asthma. Airway hyperresponsiveness can be produced experimentally in otherwise healthy subjects or animals by inflammatory damage (e.g., induced by respiratory viruses or by inhaled oxidants). Evidence is presented that cell-to-cell interactions play an important role in experimental hyperreactivity and that similar inflammatory cascades may play a similar role in clinical asthma. Although the importance of epithelial cells and neutrophils has been identified in the present studies, other inflammatory mechanisms (e.g., sensory nerve release of substance P, epithelial mast cells, eosinophils) may also play key roles. In exercise-induced bronchospasm, the stimulus (e.g., cooling or drying) must affect a cell (e.g., one near the epithelial surface) by decreasing temperature or by increasing osmolality. This signal may cause mediator release and a subsequent cascade, leading to contraction of smooth muscle. Environmental irritants (e.g., ozone) inhaled during exercise may potentiate these effects by producing further inflammation.

Topics: Animals; Arachidonic Acids; Asthma; Cell Communication; Chemotactic Factors; Dinoprostone; Dogs; Epithelial Cells; Epithelium; Humans; Hydroxyeicosatetraenoic Acids; Inflammation; Interleukin-8; Leukotriene B4; Neutrophils; Ozone; Prostaglandins E; Sputum