12-hydroxy-5-8-10-14-eicosatetraenoic-acid and Inflammation

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Animals; Arachidonic Acids; Cell Movement; Chemotaxis, Leukocyte; Cyclic GMP; Humans; Inflammation; Lipoxygenase; Macrophages; Neutrophils; Receptors, Complement; Subcellular Fractions

Acute kidney injury (AKI) due to ischemia-reperfusion (IR) is a serious and frequent complication in clinical settings, and mortality rates remain high. There are well established sex differences in renal IR, with males exhibiting greater injury following an ischemic insult compared to females. We recently reported that males have impaired renal recovery from ischemic injury vs. females. However, the mechanisms mediating sex differences in renal recovery from IR injury remain poorly understood. Elevated 12/15 lipoxygenase (LOX) activity has been reported to contribute to the progression of numerous kidney diseases. The goal of the current study was to test the hypothesis that enhanced activation of 12/15 LOX contributes to impaired recovery post-IR in males vs. females.. 13-week-old male and female spontaneously hypertensive rats (SHR) were randomized to sham or 30-minute warm bilateral IR surgery. Additional male and female SHR were randomized to treatment with vehicle or the specific 12/15 LOX inhibitor ML355 1 h prior to sham/IR surgery, and every other day following up to 7-days post-IR. Blood was collected from all rats 1-and 7-days post-IR. Kidneys were harvested 7-days post-IR and processed for biochemical, histological, and Western blot analysis. 12/15 LOX metabolites 12 and 15 HETE were measured in kidney samples by liquid chromatography-mass spectrometry (LC/MS).. Male SHR exhibited delayed recovery of renal function post-IR vs. male sham and female IR rats. Delayed recovery in males was associated with activation of renal 12/15 LOX, increased renal 12-HETE, enhanced endoplasmic reticulum (ER) stress, lipid peroxidation, renal cell death and inflammation compared to females 7-days post-IR. Treatment of male SHR with ML355 lowered levels of 12-HETE and resulted in reduced renal lipid peroxidation, ER stress, tubular cell death and inflammation 7-days post-IR with enhanced recovery of renal function compared to vehicle-treated IR male rats. ML355 treatment did not alter IR-induced increases in plasma creatinine in females, however, tubular injury and cell death were attenuated in ML355 treated females compared to vehicle-treated rats 7 days post-IR.. Our data demonstrate that sustained activation 12/15 LOX contributes to impaired renal recovery post ischemic injury in male and female SHR, although males are more susceptible on this mechanism than females.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Acute Kidney Injury; Animals; Arachidonate 15-Lipoxygenase; Female; Inflammation; Ischemia; Kidney; Male; Rats; Rats, Inbred SHR; Reperfusion Injury

EPA and DHA cause different physiological effects, which are in many cases mediated via their oxidative metabolites (oxylipins). However, metabolism studies investigating the effect of either EPA or DHA on comprehensive oxylipin patterns are lacking.. The short and long term (1, 3, 6, and 12 week) effect of 1076mg/d DHA (free of EPA) on free (unesterified) oxylipin concentrations in plasma and lipopolysacharid (LPS) stimulated blood of 12 healthy men (mean age 25.1 ± 1.5 years) was investigated.. After DHA supplementation, plasma levels of all DHA-oxylipins (HDHAs, EpDPEs, DiHDPEs) significantly increased (up to 600%) in a time-dependent fashion. Oxylipins of EPA and arachidonic acid (AA) were also affected. Whereas a slight increase in several EPA-derived hydroxy-FAs (including the RvE1 precursor 18-HEPE) and dihydroxy-FAs was observed after DHA supplementation, a trend to a slight decline in AA-derived oxylipin levels was found. In LPS stimulated blood, it is shown that DHA supplementation significantly reduces the ability of immune cells to form AA-derived COX (TXB2 and PGB2) and 12-LOX (12-HETE) eicosanoids. While no increase in EPA COX metabolites was found, n-3 PUFA 12-LOX metabolites of EPA (12-HEPE) and DHA (14-HDHA) were highly induced.. We demonstrated that DHA supplementation causes a time-dependent shift in the entire oxylipin profile suggesting a cross-linked metabolism of PUFAs and subsequent formation of oxygenated lipid mediators.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Adult; Arachidonic Acid; C-Reactive Protein; Dietary Supplements; Docosahexaenoic Acids; Eicosanoids; Fatty Acids, Unsaturated; Germany; Humans; Inflammation; Leukocyte Count; Lipopolysaccharides; Male; Oxylipins; Young Adult

To identify biomarkers of orange juice (OJ) consumption containing different doses of polyphenols and to determine its impact on oxidative stress and inflammation using an untargeted metabolomics analysis.. Thirty subjects aged 22-63 years from the BIONAOS study consumed a normal-polyphenol OJ (NPJ) or a high-polyphenol OJ (HPJ) (299 or 745 mg/L, respectively) for 12 weeks in a randomized, parallel, double-blind study. UHPLC-MS, univariate and multivariate statistical analysis and ROC curves were used to design biomarkers of consumption in serum. We propose betonicine, stachydrine, methyl glucopyranoside (alpha+beta), dihydroferulic acid and galactonate as a new metabolic signature to distinguish the intake of OJ with a different polyphenol content. Changes in metabolites related to OJ, oxidative stress and inflammation were observed. After HPJ consumption, the serum levels of hydroxyoctadecadienoic acid (9-HODE+13-HODE) and dihydroxyoctadecanoic acid (12,13-DiHOME and 9,10-DiHOME) decreased, whereas levels of 12-hydroxyeicosatetraenoic acid (12-HETE) increased. 5-HETE increased after the NPJ intervention exclusively.. We designed a new panel of biomarkers to differentiate the intake of OJs containing different doses of polyphenols. On the other hand, the consumption of an OJ with a high content of flavanones improved oxidative stress and inflammatory biomarkers.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Adult; Biomarkers; Citrus sinensis; Female; Fruit and Vegetable Juices; Gas Chromatography-Mass Spectrometry; Humans; Hydroxyeicosatetraenoic Acids; Inflammation; Male; Metabolomics; Middle Aged; Oxidative Stress; Polyphenols; Proline; Tandem Mass Spectrometry; Young Adult

Safe systemic protection from the health hazards of ultraviolet radiation (UVR) in sunlight is desirable. Green tea is consumed globally and is reported to have anti-inflammatory properties, which may be mediated through the impact on cyclooxygenase and lipoxygenase pathways. Recent data suggest that green tea catechins (GTCs) reduce acute UVR effects, but human trials examining their photoprotective potential are scarce.. We performed a double-blind, randomized, placebo-controlled trial to examine whether GTCs protect against clinical, histologic, and biochemical indicators of UVR-induced inflammation.. Healthy adults (aged 18-65 y, phototypes I-II) were randomly allocated to 1350 mg encapsulated green tea extract (540 mg GTC) with 50 mg vitamin C or placebo twice daily for 3 mo. Impact on skin erythema, dermal leukocytic infiltration, and concentrations of proinflammatory eicosanoids was assessed after solar-simulated UVR challenge, and subject compliance was determined through assay of urinary GTC metabolite epigallocatechin glucuronide.. Volunteers were assigned to the active (n = 25) or the placebo (n = 25) group. After supplementation, median (IQR) sunburn threshold (minimal erythema dose) was 28 (20-28) and 20 (20-28) mJ/cm(2) in the active and placebo groups, respectively (nonsignificant), with no difference in AUC analysis for measured erythema index after a geometric series of 10 UVR doses. Skin immunohistochemistry showed increased neutrophil and CD3(+) T-lymphocyte numbers post-UVR in both groups (P < 0.01) with no statistically significant differences between groups after supplementation. Cyclooxygenase and lipoxygenase metabolites prostaglandin E2 (vasodilator) and 12-hydroxyeicosatetraenoicacid (chemoattractant), respectively, increased after UVR (P < 0.05), with no differences between supplementation groups.. Oral GTC (1080 mg/d) with vitamin C over 3 mo did not significantly reduce skin erythema, leukocyte infiltration, or eicosanoid response to UVR inflammatory challenge. This trial was registered at clinicaltrials.gov as NCT01032031.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Administration, Oral; Adult; Antioxidants; Ascorbic Acid; Catechin; Dietary Supplements; Dinoprostone; Dose-Response Relationship, Drug; Double-Blind Method; Erythema; Female; Humans; Inflammation; Male; Middle Aged; Skin; Sunburn; Tea; Ultraviolet Rays; Young Adult

Heart failure with preserved ejection fraction (HFpEF) is a complex clinical syndrome, but a predominant subset of HFpEF patients has metabolic syndrome (MetS). Mechanistically, systemic, nonresolving inflammation associated with MetS might drive HFpEF remodeling. Free fatty acid receptor 4 (Ffar4) is a GPCR for long-chain fatty acids that attenuates metabolic dysfunction and resolves inflammation. Therefore, we hypothesized that Ffar4 would attenuate remodeling in HFpEF secondary to MetS (HFpEF-MetS). To test this hypothesis, mice with systemic deletion of Ffar4 (Ffar4KO) were fed a high-fat/high-sucrose diet with L-NAME in their water to induce HFpEF-MetS. In male Ffar4KO mice, this HFpEF-MetS diet induced similar metabolic deficits but worsened diastolic function and microvascular rarefaction relative to WT mice. Conversely, in female Ffar4KO mice, the diet produced greater obesity but no worsened ventricular remodeling relative to WT mice. In Ffar4KO males, MetS altered the balance of inflammatory oxylipins systemically in HDL and in the heart, decreasing the eicosapentaenoic acid-derived, proresolving oxylipin 18-hydroxyeicosapentaenoic acid (18-HEPE), while increasing the arachidonic acid-derived, proinflammatory oxylipin 12-hydroxyeicosatetraenoic acid (12-HETE). This increased 12-HETE/18-HEPE ratio reflected a more proinflammatory state both systemically and in the heart in male Ffar4KO mice and was associated with increased macrophage numbers in the heart, which in turn correlated with worsened ventricular remodeling. In summary, our data suggest that Ffar4 controls the proinflammatory/proresolving oxylipin balance systemically and in the heart to resolve inflammation and attenuate HFpEF remodeling.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Animals; Female; Heart Failure; Inflammation; Male; Metabolic Syndrome; Mice; Oxylipins; Stroke Volume; Ventricular Remodeling

The hydroxylase cytochrome P450 1A1 (CYP1A1) is regulated by the inflammation-limiting aryl hydrocarbon receptor (AhR), but CYP1A1 immune functions remain unclear. We observed CYP1A1 overexpression in peritoneal macrophages (PMs) isolated from mice following LPS or heat-killed Escherichia. coli (E. coli) challenge. CYP1A1 overexpression augmented TNF-α and IL-6 production in RAW264.7 cells (RAW) by enhancing JNK/AP-1 signalling. CYP1A1 overexpression also promoted 12S-hydroxy-5Z,8Z,10E,14Z-eicosatetraenoic acid (12(S)-HETE) production in activated RAW, while a 12(S)-HETE antibody attenuated and 12(S)-HETE alone induced inflammatory responses. Macrophages harbouring hydroxylase-deficient CYP1A1 demonstrated reduced 12(S)-HETE generation and LPS-induced TNF-α/IL-6 secretion. CYP1A1 overexpression also impaired phagocytosis of bacteria via decreasing the expression of scavenger receptor A (SR-A) in PMs. Mice injected with CYP1A1-overexpressing PMs were more susceptible to CLP- or E. coli-induced mortality and bacteria invading, while Rhapontigenin, a selective CYP1A1 inhibitor, improved survival and bacteria clearance of mice in sepsis. CYP1A1 and 12(S)-HETE were also elevated in monocytes and plasma of septic patients and positively correlated with SOFA scores. Macrophage CYP1A1 disruption could be a promising strategy for treating sepsis. Video abstract.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Adult; Aged; Animals; Cytochrome P-450 CYP1A1; Escherichia coli; Humans; Inflammation; Macrophages, Peritoneal; Male; MAP Kinase Kinase 4; Mice; Mice, Inbred C57BL; Middle Aged; Phagocytosis; RAW 264.7 Cells; Sepsis; Young Adult

12-HETE is a metabolite of arachidonic acid (AA). AA is normally present in membrane phospholipids. The exposure to different stimuli can trigger the release of AA through the activity of phospholipase A

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Arachidonic Acid; Humans; Inflammation; Oxidative Stress

Polyunsaturated fatty acid (PUFA) intake has increased over the last 100 yr, contributing to the current obesogenic environment. Obesity and aging are prominent risk factors for myocardial infarction (MI). How obesity interacts with aging to alter the post-MI response, however, is unclear. We tested the hypothesis that obesity in aging mice would impair the resolution of post-MI inflammation. PUFA diet (PUFA aging group) feeding to 12-mo-old C57BL/6J mice for 5 mo showed higher fat mass compared with standard lab chow (LC)-fed young (LC young group; 3-5 mo old) or aging alone control mice (LC aging group). LC young, LC aging, and PUFA aging mice were subjected to coronary artery ligation to induce MI. Despite similar infarct areas post-MI, plasma proteomic profiling revealed higher VCAM-1 in the PUFA aging group compared with LC young and LC aging groups, leading to increased neutrophil infiltration in the PUFA aging group (P<0.05). Macrophage inflammatory protein-1γ and CD40 were also increased at day 1, and myeloperoxidase remained elevated at day 5, an observation consistent with delayed wound healing in the PUFA aging group. Lipidomic analysis showed higher levels of arachidonic acid and 12(S)-hydroxyeicosatetraenoic acid at day 1 post-MI in the PUFA aging group compared with the LC aging group (all P<0.05), thereby mediating neutrophil extravasation in the PUFA aging group. The inflammation-resolving enzymes 5-lipoxygenase, cyclooxygenase-2, and heme oxyegnase-1 were altered to delay wound healing post-MI in the PUFA aging group compared with LC young and LC aging groups. PUFA aging magnifies the post-MI inflammatory response and impairs the healing response by stimulating prolonged neutrophil trafficking and proinflammatory lipid mediators.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Aging; Animals; Arachidonic Acid; CD40 Antigens; Cyclooxygenase 2; Diet, High-Fat; Fatty Acids, Omega-3; Heme Oxygenase-1; Inflammation; Lipoxygenase; Macrophage Inflammatory Proteins; Mice; Mice, Inbred C57BL; Myocardial Infarction; Neutrophil Infiltration; Obesity; Ventricular Function; Wound Healing

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Adult; Antibodies, Antineutrophil Cytoplasmic; Biopsy; Breath Tests; Case-Control Studies; Chromatography, High Pressure Liquid; Eicosanoids; Exhalation; Female; Granulomatosis with Polyangiitis; Humans; Inflammation; Lipoxygenases; Male; Middle Aged; Prostaglandin-Endoperoxide Synthases; Respiratory Function Tests; Respiratory System; Tandem Mass Spectrometry

The 12/15-Lipoxygenase (12/15-LO) and its metabolite 12(S)-Hydroxyeicosatetraenoic acid [12(S)-HETE] mediate proatherogenic responses in vascular smooth muscle cells (VSMCs). We examined the role of the nonreceptor tyrosine kinase Src in the signaling and epigenetic chromatin mechanisms involved in these processes.. Rat VSMCs (RVSMCs) were stimulated with 12(S)-HETE (0.1 micromol/L) in the presence or absence of the Src inhibitor PP2 (10 micromol/L). Src activation and downstream signaling events including inflammatory gene expression and chromatin histone H3-Lys-9/14 acetylation were examined by immunoblotting, RT-PCR, and chromatin immunoprecipitation assays, respectively. 12(S)-HETE significantly activated Src, focal adhesion kinase, Akt, p38MAPK, and CREB. Expression of monocyte chemoattractant protein-1 and interleukin-6 genes and histone H3-Lys-9/14 acetylation on their promoters were also increased by 12(S)-HETE. PP2 inhibited these responses as well as 12(S)-HETE-induced VSMC migration. Furthermore, dominant negative mutants of Src, CREB, and a histone acetyltransferase p300 significantly blocked 12(S)-HETE-induced inflammatory gene expression. In addition, growth factor induced Src signaling and downstream events including H3-Lys-9/14 acetylation and migration were significantly attenuated in VSMCs derived from 12/15-LO(-/-) mice relative to WT.. Src kinase signaling plays a central role in the proatherogenic responses mediated by 12/15-LO and its oxidized lipid metabolite 12(S)-HETE in VSMCs.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Acetylation; Animals; Arachidonate 12-Lipoxygenase; Arachidonate 15-Lipoxygenase; Atherosclerosis; Cells, Cultured; Chemokine CCL2; Chromatin Assembly and Disassembly; Cyclic AMP Response Element-Binding Protein; Enzyme Activation; Focal Adhesion Protein-Tyrosine Kinases; Gene Expression Regulation; Histones; Inflammation; Interleukin-6; Mice; Mice, Inbred C57BL; Mice, Knockout; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; p38 Mitogen-Activated Protein Kinases; Promoter Regions, Genetic; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Pyrimidines; Rats; Rats, Sprague-Dawley; Signal Transduction; src-Family Kinases; Time Factors; Transfection

Inflammation and insulin resistance associated with visceral obesity are important risk factors for the development of type 2 diabetes, atherosclerosis, and the metabolic syndrome. The 12/15-lipoxygenase (12/15-LO) enzyme has been linked to inflammatory changes in blood vessels that precede the development of atherosclerosis. The expression and role of 12/15-LO in adipocytes have not been evaluated. We found that 12/15-LO mRNA was dramatically upregulated in white epididymal adipocytes of high-fat fed mice. 12/15-LO was poorly expressed in 3T3-L1 fibroblasts and was upregulated during differentiation into adipocytes. Interestingly, the saturated fatty acid palmitate, a major component of high fat diets, augmented expression of 12/15-LO in vitro. When 3T3-L1 adipocytes were treated with the 12/15-LO products, 12-hydroxyeicosatetranoic acid (12(S)-HETE) and 12-hydroperoxyeicosatetraenoic acid (12(S)-HPETE), expression of proinflammatory cytokine genes, including tumor necrosis factor-alpha (TNF-alpha), monocyte chemoattractant protein 1 (MCP-1), interleukin 6 (IL-6), and IL-12p40, was upregulated whereas anti-inflammatory adiponectin gene expression was downregulated. 12/15-LO products also augmented c-Jun N-terminal kinase 1 (JNK-1) phosphorylation, a known negative regulator of insulin signaling. Consistent with impaired insulin signaling, we found that insulin-stimulated 3T3-L1 adipocytes exhibited decreased IRS-1(Tyr) phosphorylation, increased IRS-1(Ser) phosphorylation, and impaired Akt phosphorylation when treated with 12/15-LO product. Taken together, our data suggest that 12/15-LO products create a proinflammatory state and impair insulin signaling in 3T3-L1 adipocytes. Because 12/15-LO expression is upregulated in visceral adipocytes by high-fat feeding in vivo and also by addition of palmitic acid in vitro, we propose that 12/15-LO plays a role in promoting inflammation and insulin resistance associated with obesity.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; 3T3-L1 Cells; Adipocytes; Adiponectin; Animals; Arachidonate 12-Lipoxygenase; Arachidonate 15-Lipoxygenase; Cell Differentiation; Cytokines; Disease Models, Animal; Gene Expression Regulation, Enzymologic; Inflammation; Inflammation Mediators; Insulin; Insulin Receptor Substrate Proteins; Insulin Resistance; Leukotrienes; Male; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinase 8; Obesity; Palmitic Acid; Phosphorylation; Proto-Oncogene Proteins c-akt; RNA, Messenger; Signal Transduction; Time Factors; Up-Regulation

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Animals; Arachidonate 12-Lipoxygenase; Arachidonate 15-Lipoxygenase; beta-N-Acetylhexosaminidases; Chitinases; Cytokines; Inflammation; Lectins; Lipoxygenase Inhibitors; Signal Transduction; Th2 Cells

Increased expression and activity of 12/15-lipoxygenase (12/15-LO) in vascular smooth muscle cells (VSMCs) play a key role in the pathogenesis of diabetes and vascular complications. However, the consequences of 12/15-LO overexpression for VSMC migration and inflammatory gene expression are not known. In this study, 12/15-LO was overexpressed using adeno- and baculoviral vectors in human VSMC (HVSMCs) and proatherogenic responses compared with control enhanced green fluorescent protein (EGFP)-expressing cells. HVSMCs transduced with 12/15-LO viruses expressed high levels of enzymatically active protein and produced increased levels of the LO product, 12(S)-hydroxyeicosatetraenoic acid. 12/15-LO-overexpressing HVSMCs exhibited increased oxidant stress, activation of p38 mitogen-activated protein kinase, migration and inflammatory gene expression relative to HVSMCs expressing EGFP. Furthermore, inflammatory gene expression induced by 12/15-LO overexpression was abolished by anti-oxidants, siRNAs targeting p65 (nuclear factor-kappaB), or new-generation baculoviruses expressing inhibitory IkappaBalpha or IkappaBalpha superrepressor mutant. Thus, we have used novel viral vector delivery systems, including baculoviruses, for the first time to deliver foreign genes into VSMCs and thereby demonstrated that 12/15-LO overexpression increases oxidant stress, mitogen-activated protein kinase activation, migration and inflammatory genes in VSMCs and that NF-kappaB is a key downstream effector. Enhanced proatherogenic responses in VSMCs triggered by increased 12/15-LO levels under pathological conditions may contribute to vascular dysfunction.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Adenoviridae; Animals; Antioxidants; Arachidonate 12-Lipoxygenase; Arachidonate 15-Lipoxygenase; Baculoviridae; Cell Movement; Cells, Cultured; Enzyme Activation; Gene Expression; Genetic Vectors; Humans; I-kappa B Proteins; Inflammation; Inflammation Mediators; Mice; Multienzyme Complexes; Muscle, Smooth, Vascular; Mutation; Myocytes, Smooth Muscle; NF-KappaB Inhibitor alpha; Oxidative Stress; p38 Mitogen-Activated Protein Kinases; RNA Interference; RNA, Small Interfering; Transcription Factor RelA; Transduction, Genetic; Up-Regulation

The leukocyte-type 12/15-lipoxygenase (12/15-LO) has been implicated in the pathogenesis of atherosclerosis, hypertension, and diabetes. 12/15-LO and its products are associated with LDL oxidation, cellular growth, migration, adhesion, and inflammatory gene expression in monocytes/macrophages, endothelial cells, and vascular smooth muscle cells (VSMCs). Our objective, therefore, was to develop novel expression vectors for short interfering RNAs (siRNAs) targeting 12/15-LO to evaluate its functional relevance in macrophages and VSMCs. We used a PCR-based approach to rapidly identify effective siRNA target sites on mouse 12/15-LO and initially tested their efficacy on a fusion construct of 12/15-LO cDNA and enhanced green fluorescent protein. We then cloned these U6 promoter+siRNA PCR products into plasmid vectors [short hairpin siRNAs (shRNAs)] to knockdown endogenous 12/15-LO expression in mouse macrophages and also rat and mouse VSMCs. Furthermore, the functional effects of shRNA-mediated 12/15-LO knockdown were noted by the reduced oxidant stress and chemokine [monocyte chemoattractant protein-1 (MCP-1)] expression in a differentiated mouse monocytic cell line as well as by the reduced cellular adhesion and fibronectin expression in VMSCs. Knocking down 12/15-LO expression also reduced the expression of inflammatory genes, MCP-1, vascular cell adhesion molecule-1, and interleukin-6 in VSMCs. Our results illustrate the functional relevance of 12/15-LO activation in macrophages and VSMCs and its relationship to oxidant stress and inflammation.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Animals; Arachidonate 12-Lipoxygenase; Arachidonate 15-Lipoxygenase; Base Sequence; Blotting, Western; Cell Adhesion; Cell Line; Cell Movement; Cells, Cultured; Chemokine CCL2; Chemokines; DNA Primers; DNA, Complementary; Down-Regulation; Endothelium, Vascular; Ethidium; Fibronectins; Gene Silencing; Green Fluorescent Proteins; Humans; Immunoblotting; Inflammation; Lipoproteins, LDL; Macrophages; Mice; Microscopy, Fluorescence; Molecular Sequence Data; Monocytes; Myocytes, Smooth Muscle; Oxidants; Oxidative Stress; Polymerase Chain Reaction; Promoter Regions, Genetic; Protein Binding; Rats; Recombinant Fusion Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Small Interfering; Superoxides; Transfection

Lipoxygenases (LOX) contribute to vascular disease and inflammation through generation of bioactive lipids, including 12-hydro(pero)xyeicosatetraenoic acid (12-H(P)ETE). The physiological mechanisms that acutely control LOX product generation in mammalian cells are uncharacterized. Human platelets that contain a 12-LOX isoform (p12-LOX) were used to define pathways that activate H(P)ETE synthesis in the vasculature. Collagen and collagen-related peptide (CRP) (1 to 10 microg/mL) acutely induced platelet 12-H(P)ETE synthesis. This implicated the collagen receptor glycoprotein VI (GPVI), which signals via the immunoreceptor-based activatory motif (ITAM)-containing FcRgamma chain. Conversely, thrombin only activated at high concentrations (> 0.2 U/mL), whereas U46619 and ADP alone were ineffective. Collagen or CRP-stimulated 12-H(P)ETE generation was inhibited by staurosporine, PP2, wortmannin, BAPTA/AM, EGTA, and L-655238, implicating src-tyrosine kinases, PI3-kinase, Ca2+ mobilization, and p12-LOX translocation. In contrast, protein kinase C (PKC) inhibition potentiated 12-H(P)ETE generation. Finally, activation of the immunoreceptor tyrosine-based inhibitory motif (ITIM)-containing platelet endothelial cell adhesion molecule (PECAM-1) inhibited p12-LOX product generation. This study characterizes a receptor-dependent pathway for 12-H(P)ETE synthesis via the collagen receptor GPVI, which is negatively regulated by PECAM-1 and PKC, and demonstrates a novel link between immune receptor signaling and lipid mediator generation in the vasculature.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Adenosine Diphosphate; Amino Acid Motifs; Arachidonate 12-Lipoxygenase; Arachidonic Acid; Blood Platelets; Calcimycin; Calcium Signaling; Carrier Proteins; Collagen; Cyclooxygenase 1; Egtazic Acid; Enzyme Activation; Enzyme Inhibitors; Humans; Inflammation; Isoenzymes; Leukotrienes; Membrane Proteins; p38 Mitogen-Activated Protein Kinases; Peptides; Phosphorylation; Platelet Activation; Platelet Endothelial Cell Adhesion Molecule-1; Platelet Membrane Glycoproteins; Prostaglandin-Endoperoxide Synthases; Protein Kinase C; Protein Processing, Post-Translational; Protein Transport; Quinolines; Receptors, IgG; Thrombin

Atherosclerosis is a major complication of diabetes. Up to 16 weeks of age, the db/db mouse is insulin-resistant and hyperglycemic and is a good model of Type 2 diabetes. After approximately 16 weeks of age, the mice develop pancreatic beta cell failure that can progress to a Type 1 diabetes phenotype. We have previously shown that glucose increases production of endothelial 12/15 lipoxygenase (12/15LO) products in vitro. In young 10-week-old Type 2 diabetic db/db mice, we found significant elevations in levels of urinary 12/15LO products, 12S-hydroxyeicosatetraenoic acid (12S-HETE) and 13S-hydroxyoctadecaenoic acid (13S-HODE) in vivo compared with C57BLKS/J mice. Using isolated primary aortic endothelial cells (ECs) from db/db mice and WEHI78/24 mouse monocyte cells in static adhesion assays, we found increased WEHI monocyte adhesion to db/db ECs (14 +/- 2 monocytes/field for db/db ECs versus 4 +/- 1 monocytes/field for C57BLKS/J ECs, p < 0.002). Thus, ECs from db/db mice appear to be "pre-activated" to bind monocytes. Analysis of db/db ECs revealed a 2-fold elevation in 12/15LO protein compared with C57BLKS/J EC. To determine that 12/15LO products were responsible for the increased monocyte adhesion observed with db/db ECs, we inhibited expression of murine 12/15LO using either an adenovirus expressing a ribozyme to 12/15LO (AdRZ) or with the 12/15LO inhibitor cinnamyl-3,4-dihydroxy-alpha-cyanocinnamate. Treatment of db/db ECs for 48 h with AdRZ or 4 h with 10 microm cinnamyl-3,4-dihydroxy-alpha-cyanocinnamate significantly reduced monocyte adhesion to db/db endothelium (p < 0.009). Thus, inhibition of the murine 12/15LO in db/db mice significantly reduced monocyte/endothelial interactions. We also found that adhesion of monocytes to diabetic db/db ECs was mediated by interactions of alpha4beta1 integrin on monocytes with endothelial vascular cell adhesion molecule 1 and connecting segment 1 fibronectin and interactions of beta2 integrins with endothelial intercellular adhesion molecule 1. In summary, regulation of the 12/15LO pathway is important for mediating early vascular changes in diabetes. Modulation of the 12/15LO pathway in the vessel wall may provide therapeutic benefit for early vascular inflammatory events in diabetes.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Animals; Aorta; Arachidonate 12-Lipoxygenase; Arachidonate 15-Lipoxygenase; Cell Adhesion; Eicosanoids; Endothelium, Vascular; Fibronectins; Flow Cytometry; Immunoassay; Inflammation; Islets of Langerhans; Linoleic Acids; Male; Mice; Mice, Inbred C57BL; Mitochondria; Monocytes; Phenotype; Reactive Oxygen Species

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; 8,11,14-Eicosatrienoic Acid; Animals; Burns; Contact Lenses; Cytochrome P-450 Enzyme System; Disease Models, Animal; Eicosanoids; Eye Injuries; Inflammation; Neovascularization, Physiologic; Rabbits; Wound Healing

Human esophageal adenocarcinoma (EAC) develops in a sequence from gastroesophageal reflux disease (GERD), columnar-lined esophagus (CLE), dysplasia, and eventually to EAC. We established a rat surgical EAC model with esophagogastroduodenal anastomosis (EGDA) to mimic the staged process of esophageal adenocarcinogenesis. Profiling of the AA metabolites with mass spectrometry showed that prostaglandin E2 (PGE2), leukotriene B4 (LTB4), 15-hydroeicosatetraenoic acid (HETE), 12-HETE, 8-HETE and 5-HETE all increased at the esophagoduodenal junction after EGDA as compared with the proximal esophagus, with PGE2 as the major metabolite. Consistent with this profile, cyclooxygenase 2 (Cox2) was overexpressed in the basal cell layer of esophageal squamous epithelium, CLE cells and EAC tumor cells of the EGDA rats, as compared with the normal esophageal epithelium. Sulindac (a Cox inhibitor), nordihydroguaiaretic acid (NDGA, a lipoxygenase inhibitor) and alpha-difluoromethylornithine (DFMO, an ornithine decarboxylase inhibitor) were tested for their possible inhibitory actions against the formation of EAC in the rat EGDA model. In a short-term study (for 4 weeks after surgery), dietary administration of both sulindac (300 and 600 p.p.m.) and NDGA (100 p.p.m.) effectively reduced the EGDA-induced inflammation. In a long-term chemoprevention study (for 40 weeks after surgery), 300 p.p.m. sulindac, alone or in combination with 100 p.p.m. NDGA or 0.5% DFMO, decreased the tumor incidence from 57.7 to 26.9%, or 16.7 or 20%, respectively (P < 0.05). NDGA alone (100 and 200 p.p.m.) slightly decreased the tumor incidence to 52.4 and 37%, respectively, although the difference was not statistically significant. DFMO alone did not show significant effects on tumor incidence. Inhibition of tumor formation by sulindac was correlated with lowered levels of PGE2. In conclusion, sulindac exerted its chemopreventive effect against the formation of EAC in the rat EGDA model possibly through its inhibition of Cox.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Animals; Arachidonic Acid; Body Weight; Cyclooxygenase 2; Dinoprostone; Eflornithine; Esophageal Neoplasms; Esophagus; Gas Chromatography-Mass Spectrometry; Hydroxyeicosatetraenoic Acids; Immunoenzyme Techniques; In Situ Hybridization; Inflammation; Isoenzymes; Leukotriene B4; Male; Masoprocol; Mass Spectrometry; Neoplasms; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Sprague-Dawley; Sulindac; Time Factors

Increased production of 12-hydroxyeicosatetraenoic acid [12(R)-HETE] and 12-hydroxyeicosatrienoic acid [12(R)-HETrE] positively correlates with the in vivo progression of ocular surface inflammation in rabbits. Tear film was collected from human subjects with inflamed eyes to determine whether these eicosanoids could be detected from endogenous sources.. Control and inflamed eyes were assessed and assigned a subjective inflammatory score. Tears were collected and extracted with an internal standard. Single-ion-monitoring gas chromatography-mass spectrometry (SIM-GC-MS) was performed to quantitate endogenous levels of 12-HETE and 12-HETrE.. 12-HETrE was detected in the tear film of both control and inflamed eyes, with the mean level being seven times higher in inflamed tears. 12-HETE was not detected in control tears and was detected in only 6 of 38 inflamed-eye tear samples.. The current findings demonstrate that the human eye produces detectable amounts of 12-HETrE, which is released into the tear flow. The increased levels of 12-HETrE associated with ocular surface inflammation suggest that this eicosanoid may contribute to inflammation of the ocular surface in humans.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Arachidonic Acid; Conjunctivitis; Eye Foreign Bodies; Gas Chromatography-Mass Spectrometry; Humans; Inflammation; Iridocyclitis; Keratitis; Keratitis, Herpetic; Keratoconjunctivitis; Tears

In this study we set out to investigate whether the inflammatory agents, bradykinin (BK) and platelet activating factor (PAF), affect the lipoxygenase pathway in rat skin in vivo and whether the main products so formed may be involved in the inflammatory actions of these agents. In vitro preparations of epidermis were also investigated to determine whether lipoxygenases are stimulated by these agents. We also investigated the actions of arachidonic acid and 12(S)-HPETE as substrates for the lipoxygenases. Our results indicated that 12-lipoxygenase is actively and selectively stimulated in a dose-dependent way in both preparations by the administration of BK and PAF; the main product, 12-HETE, was shown by chiral analysis to be exclusively of the S-configuration, indicating that 12(S)-lipoxygenase was present in the rat skin and was stimulated by these inflammatory agents. Hepoxilins were also formed but to a lesser extent in both in vivo and in vitro preparations. In separate experiments, 12(S)-HETE administered intradermally on its own (40 ng/site), increased vascular permeability as also seen with bradykinin (100 ng/site) and PAF (10 ng/site). However, unlike previously observed with hepoxilin A3 administration, 12(S)-HETE did not stimulate the action of BK on vascular permeability, suggesting that the two compounds may have different mechanisms of action to enhance inflammation. These observations suggest that the vascular permeability and plasma extravasation observed with both inflammatory agents (BK and PAF) may be mediated at least in part through the activation of 12(S)-lipoxygenase, resulting in enhanced formation of 12(S)-HETE which causes acute inflammation.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; 8,11,14-Eicosatrienoic Acid; Animals; Arachidonate 12-Lipoxygenase; Bradykinin; Capillary Permeability; Enzyme Activation; Inflammation; Inflammation Mediators; Male; Platelet Activating Factor; Rats; Rats, Wistar; Skin

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Asthma; Biomarkers; Blood Chemical Analysis; Case-Control Studies; Chromatography, High Pressure Liquid; Humans; Hydroxyeicosatetraenoic Acids; Inflammation; Inflammation Mediators; Reference Standards; Rhinitis, Allergic, Seasonal

The corneal epithelium metabolizes arachidonic acid by a cytochrome P450-(CYP) mediated pathway to 12(R)hydroxy-5,8,10,14-eicosatrienoic acid [12(R)-HETE] and 12(R)hydroxy-5,8,14-eicosatrienoic acid [12(R)-HETrE]. Both metabolites possess potent inflammatory properties with 12(R)-HETrE being a powerful angiogenic factor and assume the role of inflammatory mediators in hypoxia- and chemical-induced injury in the cornea, in vivo. We developed an in vitro model of corneal organ culture to characterize the biochemical and molecular events involved in the increased synthesis of these metabolites. These cultured corneas exhibit epithelial cytochrome P450 CYP-dependent 12(R)-HETE and 12(R)-HETrE synthesis as indicated by chiral analysis and by the ability of CYP enzyme inhibitors to repress their synthesis. Hypoxia greatly and selectively stimulated the synthesis of 12(R)-HETE (7-fold over control normoxic conditions) and 12(R)-HETrE. The bacterial endotoxin, lipopolysaccharide, also increased the synthesis of these eicosanoids, substantiating the notion that this activity may function as an inflammatory pathway. These metabolites were detected in the culture medium by gas chromatography/mass spectroscopy (GC/MS) analysis and their levels significantly increased in hypoxia-treated corneas, further indicating their endogenous formation in response to injury. This in vitro model provides an excellent preparation for studying factors regulating the synthesis of these inflammatory eicosanoids and for isolating, identifying and characterizing the CYP protein responsible for their synthesis.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; 8,11,14-Eicosatrienoic Acid; Animals; Cell Hypoxia; Culture Media; Cytochrome P-450 Enzyme System; Epithelium, Corneal; Inflammation; Lipopolysaccharides; Organ Culture Techniques; Rabbits

The arylpropionate anti-inflammatory drug, carprofen, was administered intravenously as the racemate at a dose rate of 0.7 mg kg-1 body weight to six Friesian bull calves aged 16-17 weeks. Anti-inflammatory and pharmacokinetic properties were investigated using a tissue cage model of inflammation based on intracaveal injection of the mild irritant, carrageenin. Carprofen displayed enantioselective pharmacokinetics, with the R(-) enantiomer predominating in plasma at all measuring times. Elimination half-life and mean residence time were shorter and volume of distribution and clearance were greater for the S(+) than for the R(-) enantiomer. Penetration of both enantiomers into transudate (non-stimulated tissue cage) was poor but penetration into exudate (carrageenin-stimulated tissue cage) was good. Carprofen failed to reduce exudate concentration of prostaglandin E2 and the reductions in 12-hydroxyeicosatetraenoic acid were non-significant at most sampling times. The long elimination half-life of both R(-) and S(+) carprofen enantiomers and their ready penetration into and slow clearance from inflammatory exudate indicate that the drug is likely to have a long duration of action in calves. The mechanism of action is unknown but it is unlikely to involve inhibition of either cyclooxygenase or 12-lipoxygenase.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Acute Disease; Animals; Anti-Inflammatory Agents, Non-Steroidal; Carbazoles; Carrageenan; Cattle; Cattle Diseases; Cross-Over Studies; Dinoprostone; Exudates and Transudates; Hydroxyeicosatetraenoic Acids; Inflammation; Male; Proteins; Time Factors; Zymosan

Previously, we have shown that Pseudomonas aeruginosa lipase and phospholipase C (PLC), two extracellular lipolytic enzymes, interact with each other during 12-hydroxyeicosatetraenoic acid (HETE) generation from human platelets. In this regard. the addition of purified P. aeruginosa lipase to PLC-containing crude P. aeruginosa culture supernatants enhances the generation of the chemotactically active 12-HETE from human platelets. Therefore, we analyzed the interaction of purified P. aeruginosa lipase and purified hemolytic P. aeruginosa PLC with regard to inflammatory mediator release from human platelets, neutrophilic and basophilic granulocytes, and monocytes. Purified P. aeruginosa PLC, but not purified lipase by itself, induced 12-HETE generation from human platelets, the generation of leukotriene B4 (LTB4) and oxygen metabolites, enzyme release from human neutrophils, and histamine release from basophils but diminished interleukin-8 (IL-8) release from human monocytes in a dose-dependent manner. The addition of purified lipase enhanced PLC-induced 12-HETE and LTB4 generation, did not influence enzyme, histamine, or IL-8 release, but diminished the PLC-induced chemiluminescent response. Similar results were obtained when the hemolytic PLC from Clostridium perfringens was used instead of P. aeruginosa PLC. For further comparison, we used the well-defined calcium ionophore A23187 and phorbol-12-myristate-13-acetate (PMA) as stimuli. Lipase enhanced calcium ionophore-induced LTB4 generation and beta-glucuronidase release but reduced calcium ionophore-induced and PMA-induced chemiluminescence. In parallel, we analyzed the role of lipase in a crude P. aeruginosa culture supernatant containing PLC and lipase. Lipase activity in the P. aeruginosa culture supernatant was inhibited by treatment with the lipase-specific inhibitor hexadecylsulfonyl fluoride, leaving the activity of PLC unaffected. The capacity of "lipase-inactivated culture supernatant" to induce 12-HETE and LTB4 generation was diminished by 50 to 100%. Our results suggest that the simultaneous secretion of lipase and PLC by P. aeruginosa residing in an infected host may result in severe pathological effects which cannot be explained by the sole action of the individual virulence factor on inflammatory effector cells.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Basophils; Blood Platelets; Chemotaxis, Leukocyte; Enzymes; Histamine; Humans; Hydroxyeicosatetraenoic Acids; Inflammation; Interleukin-8; Leukocytes; Leukotriene B4; Lipase; Luminescent Measurements; Monocytes; Neutrophils; Pseudomonas aeruginosa; Type C Phospholipases

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Acrylates; Animals; Anti-Inflammatory Agents, Non-Steroidal; Arachidonic Acid; Calcium; Cell Line; Edema; Humans; Hydroxyeicosatetraenoic Acids; Inflammation; Leukotriene B4; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; Pyridines; Receptors, Leukotriene B4; Tumor Cells, Cultured

Tolfenamic acid was administered to beagle dogs at 2, 4 and 8 mg/kg bodyweight i.m. and the concentration of drug in plasma and in inflamed (administered carrageenan) and non-inflamed subcutaneous tissue cage fluid was measured. The concentration of thromboxane B2 in serum from blood allowed to clot under standardized conditions was determined and the concentrations of prostaglandin E2, 12-hydroxyeicosatetraenoic acid (12-HETE) and leucocyte numbers were measured in fluid from the carrageenan administered tissue cages. Skin temperature was also measured over each tissue cage following administration of drug. Tolfenamic acid displayed linear pharmacokinetics since the area under the plasma concentration time curve (AUC) values were 13.74 +/- 1.88, 29.82 +/- 6.53 and 50.52 +/- 5.73 micrograms/ml.h following administration of 2, 4 and 8 mg/kg, respectively. Tolfenamic acid proved to be a potent inhibitor of ex vivo thromboxane B2 generation in clotting blood. Maximal inhibition was greater than 80% at all dose rates and 97% at the 8 mg/kg dose rate 1 h after drug administration. It also proved to be a potent inhibitor of prostaglandin E2 production in inflammatory exudate, and significantly (P < 0.05) decreased prostaglandin E2 production at all dose levels. Tolfenamic acid did not significantly alter 12-HETE generation or white blood cell accumulation in inflammatory exudate. Tolfenamic acid significantly reduced the elevated skin temperature over carrageenan administered cages at all dose levels.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Count; Dinoprostone; Dogs; Dose-Response Relationship, Drug; Exudates and Transudates; Female; Hydroxyeicosatetraenoic Acids; Inflammation; Injections, Intramuscular; Leukocyte Count; Male; ortho-Aminobenzoates; Skin Temperature; Thromboxane B2

We analyzed the role of soluble purified Pseudomonas aeruginosa alginate on Escherichia coli K-12 (pANN5211) as well as on Staphylococcus aureus 121c-induced inflammatory mediator release from human platelets, granulocytes, and basophils. In the presence of alginate (1-4 mg/ml), the mucoid exopolysaccharide of P. aeruginosa, the bacteria-induced inflammatory mediator release was modulated as follows: (1) the E. coli- as well as S. aureus-induced chemiluminescence response from human neutrophils increased 2- to 3-fold and 5- to 6-fold, respectively; (2) the E. coli-induced leukotriene B4 formation from human neutrophils was enhanced (from 29.17 +/- 1.8 up to 36.9 +/- 4 ng/10(7) cells) as was also observed for the E. coli- and S. aureus-induced histamine release (3- to 4-fold) and the 12-hydroxyeicosatetraenoic acid generation from human platelets (2-fold), and (3) prolonged duration of the E. coli-induced increase in CD11b expression was observed. Alginate by itself was inactive. Our results provide evidence that alginate interacts with hemolysin-producing E. coli and S. aureus bacteria and thus leads to a modulation of the cellular response pattern, which leads to the local destruction of the lung in cystic fibrosis.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Alginates; Escherichia coli; Histamine Release; Humans; Hydroxyeicosatetraenoic Acids; In Vitro Techniques; Inflammation; Leukocytes; Luminescent Measurements; Pseudomonas aeruginosa; Pseudomonas Infections; Respiratory Burst; Staphylococcus aureus

Normal human epidermal melanocytes became swollen and more dendritic with an increase in the amount of tyrosinase and immunoreactive b-locus protein when they were cultured for 2 days with the following arachidonic acid metabolites: prostaglandin (PG) D2, leukotriene (LT) B4, LTC4, LTD4, LTE4, thromboxane (TX) B2 and 12-hydroxy eicosatetraenoic acid (12-HETE). The effect of LTC4 was particularly strong compared to that of PGE2, about which we have previously reported. On the other hand, PGE1, PGF2 alpha and 6-ketoPGF1 alpha did not show any significant stimulatory effect. These data suggest that arachidonate-derived chemical mediators, especially LTC4, may be responsible for the induction of post-inflammatory hyperpigmentation of the skin.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Adult; Arachidonic Acids; Cell Division; Fibroblast Growth Factor 2; Fluorescent Antibody Technique; Humans; Hydroxyeicosatetraenoic Acids; Inflammation; Leukotrienes; Male; Melanocytes; Monophenol Monooxygenase; Prostaglandin D2; Skin Pigmentation; Thromboxane B2

Uncovered fetal rabbit excisional wounds do not exhibit any classic signs of healing; wounds covered with an impermeable cover do contract, reepithelialize, and exhibit inflammation. Prostaglandin E2 (PGE2) is elevated in amniotic fluid, acting as an immunosuppressant at the maternal-fetal interface. Full-thickness excisional wounds were made on 25-day gestational age rabbit fetuses. Half the wounds were covered with an impermeable cover. Tissue from covered, uncovered, and nonwounded fetuses was examined 72 h after wounding for arachidonic acid metabolites. Uncovered wounds had significantly (P less than or equal to 0.05) elevated levels of PGE2, PGF2 alpha, and 12-HETE versus covered wounds and control tissue. Covered wounds had significantly elevated levels of 15-HETE compared to uncovered and control tissue. The elevated PGE2 in uncovered wounds may act as a fetal immunosuppressant; covered wounds (lower PGE2) developed cellular inflammation. Further investigations of these interactions may permit modulation of adult inflammation.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Amniotic Fluid; Animals; Arachidonic Acids; Dinoprost; Dinoprostone; Female; Fetus; Gestational Age; Hydroxyeicosatetraenoic Acids; Inflammation; Leukotrienes; Occlusive Dressings; Pregnancy; Prenatal Injuries; Rabbits; Silicones; Sutures; Wound Healing; Wounds, Penetrating

Despite the postulated role of arachidonic acid-derived metabolites in the pathophysiology of chronic inflammatory dermatoses such as psoriasis and atopic or contact dermatitis, the cutaneous effects of their chronic application have not yet been investigated. We therefore studied systematically the effects of chronic intracutaneous administration of arachidonic acid, prostaglandin E2 (PGE2), leukotriene B4 (LTB4), and 12-hydroxyeicosatetraenoic acid (12-HETE) in guinea pigs, and describe previously unrecognized findings partly different from those reported in the past for short-term or topical application of these inflammatory mediators. Leukotriene B4 and 12-HETE led to massive histologic changes characteristic of leukocytoclastic vasculitis. These changes could be prevented by concomitant PGE2 administration. In epidermis, LTB4 and 12-HETE caused some spongiosis as well as hyperplasia and increased tritiated thymidine autoradiographic labeling index. Arachidonic acid and PGE2 alone had little effect. These data suggest that in addition to other inflammatory or hyperproliferative dermatoses, arachidonic acid metabolites formed via lipoxygenase pathways could play a major role in leukocytoclastic vasculitis, whereas PGs could exert a tissue-protective effect.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Animals; Arachidonic Acid; Arachidonic Acids; Dinoprostone; Epidermis; Female; Guinea Pigs; Hydroxyeicosatetraenoic Acids; Inflammation; Injections; Leukotriene B4; Prostaglandins E; Skin; Vasculitis

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Adult; Eicosanoic Acids; Erythema; Female; Humans; Hydroxyeicosatetraenoic Acids; Inflammation; Leukotriene B4; Male; Photosensitivity Disorders; Skin; Ultraviolet Rays

Monohydroxy acids (HETEs) and leukotriene B4 (LTB4) metabolites of arachidonic acid were measured in skin of healthy volunteers after ultraviolet B irradiation, and in the uninvolved skin of psoriatics after topical dithranol application. Exudate was collected from suction bullae on control and inflamed abdominal skin, and analysed for 12-HETE and PGE2 by GC-MS and LTB4 by bioassay. 12-HETE and PGE2 were raised at 24 h but not at 72 h after u.v.B irradiation: control and 24 h values were 13.7 and 41.5 ng ml-1 (P less than 0.05, n = 6) for 12-HETE respectively, and 4.5 and 30.2 ng ml-1 (P less than 0.01, n = 6) for PGE2. Dithranol application raised PGE2 levels from 23.1 ng ml-1 in control exudate to 62 ng ml-1 (P less than 0.01, n = 6) at 24 h before declining to base levels at 72 h. However, 12-HETE was raised at 72 h (200 ng ml-1, P less than 0.01, n = 5) but not at 24 h (104 ng ml-1) compared to control levels (50 ng ml-1, n = 5). The levels of the LTB4 were low (less than 100 pg ml-1), and no significant increases were observed. Arachidonic acid in inflamed skin can be metabolised by the cyclo-oxygenase and lipoxygenase pathway. It is probable that the lipoxygenase product 12-HETE is involved in these inflammatory reactions.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Adult; Anthralin; Arachidonic Acid; Arachidonic Acids; Dinoprostone; Humans; Hydroxyeicosatetraenoic Acids; Inflammation; Leukotriene B4; Lipoxygenase; Male; Prostaglandins E; Psoriasis; Radiation Injuries; Skin; Time Factors; Ultraviolet Rays

1. The inflammatory effects of hydroperoxy (HPETE) and hydroxy (HETE) acids, synthesized by arachidonic acid lipoxygenases, have been investigated in rabbit skin. 2. High doses (10-20 micrograms) of 5-, 12- or 15-HPETE or the 5,12-di-hydroxy acid, leukotriene B4 (0.1-1 micrograms), caused small but significant increases in plasma exudation following intra-dermal injection. 3. Leukotriene B4 was equipotent with prostaglandin E2 and prostacyclin in potentiating bradykinin-induced plasma exudation, and was 100 times more active in this property than any other lipoxygenase product tested. 4. Leukotriene B4-induced plasma exudation was enhanced by prostaglandin E2. 5. The mono-HETEs were relatively inactive in causing or enhancing plasma exudation. 6. Leukotriene B4 (0.1 microgram) or prostaglandin E1 (1.0 micrograms) significantly elevated leukocyte accumulation in rabbit skin, whereas PGE2, 5-HPETE, 5-HETE, 12-HPETE or 12-HETE were inactive at doses up to 1 microgram.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Animals; Arachidonic Acids; Bradykinin; Dose-Response Relationship, Drug; Epoprostenol; Exudates and Transudates; Inflammation; Leukocytes; Leukotriene B4; Leukotrienes; Lipid Peroxides; Prostaglandins E; Rabbits; Skin

The development of chronic inflammation in adjuvant arthritic rats was found to be strongly correlated with the appearance in serum of a factor (HSF) which enhanced the formation of 12-L-HETE by platelet-lipoxygenase, and with the serum-concentration of 12-L-HETE. The latter was determined by scanning at 235 nm after extraction and high performance thin-layer chromatography. Arthritic rat platelet-rich plasma (PRP) converted exogenous arachidonic acid to 12-L-HETE at a rate 2.6-fold higher than control rat PRP. By resuspending arthritic rat platelets in normal rat plasma, and normal rat platelets in arthritic rat plasma, this increase in conversion rate was found to be caused by HSF present in the arthritic rat plasma. Treatment of arthritis with non-steroidal anti-inflammatory drugs inhibited HSF activity as well as the increase in serum-12-L-HETE concentration, which indicates a prostaglandin-mediated mechanism of HSF synthesis or release.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Animals; Anti-Inflammatory Agents; Arachidonic Acids; Arthritis; Arthritis, Experimental; Chronic Disease; Female; Inflammation; Rats; Rats, Inbred Strains

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Animals; Arachidonic Acids; Carrageenan; Granuloma; Indomethacin; Inflammation; Lipoxygenase Inhibitors; Male; Prostaglandins E; Rats; Time Factors

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Airway Obstruction; Animals; Arachidonic Acids; Capillary Permeability; Chemotactic Factors; Constriction, Pathologic; Eosinophils; Guinea Pigs; Humans; Hypersensitivity, Immediate; Inflammation; Leukotriene B4; Lipoxygenase; Muscle Contraction; Muscle, Smooth; Neutrophils; Rats; Skin; SRS-A; Trachea

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Arachidonic Acids; Disease Models, Animal; Fatty Acids; Granuloma; Inflammation; Prostaglandins E