51
|
Lee SJ, Choi EK, Seo KW, Bae JU, Kim YH, Park SY, Oh SO, Kim CD. 5-Lipoxygenase plays a pivotal role in endothelial adhesion of monocytes via an increased expression of Mac-1. Cardiovasc Res 2013; 99:724-33. [DOI: 10.1093/cvr/cvt135] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
|
52
|
Mothe-Satney I, Filloux C, Amghar H, Pons C, Bourlier V, Galitzky J, Grimaldi PA, Féral CC, Bouloumié A, Van Obberghen E, Neels JG. Adipocytes secrete leukotrienes: contribution to obesity-associated inflammation and insulin resistance in mice. Diabetes 2012; 61:2311-9. [PMID: 22688342 PMCID: PMC3425405 DOI: 10.2337/db11-1455] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Leukotrienes (LTs) are potent proinflammatory mediators, and many important aspects of innate and adaptive immune responses are regulated by LTs. Key members of the LT synthesis pathway are overexpressed in adipose tissue (AT) during obesity, resulting in increased LT levels in this tissue. We observed that several mouse adipocyte cell lines and primary adipocytes from mice and humans both can secrete large amounts of LTs. Furthermore, this production increases with a high-fat diet (HFD) and positively correlates with adipocyte size. LTs produced by adipocytes play an important role in attracting macrophages and T cells in in vitro chemotaxis assays. Mice that are deficient for the enzyme 5-lipoxygenase (5-LO), and therefore lack LTs, exhibit a decrease in HFD-induced AT macrophage and T-cell infiltration and are partially protected from HFD-induced insulin resistance. Similarly, treatment of HFD-fed wild-type mice with the 5-LO inhibitor Zileuton also results in a reduction of AT macrophages and T cells, accompanied by a decrease in insulin resistance. Together, these findings suggest that LTs represent a novel target in the prevention or treatment of obesity-associated inflammation and insulin resistance.
Collapse
Affiliation(s)
- Isabelle Mothe-Satney
- INSERM, U907, Nice, France
- Faculty of Medicine, University of Nice-Sophia Antipolis, Nice, France
| | - Chantal Filloux
- INSERM, U907, Nice, France
- Faculty of Medicine, University of Nice-Sophia Antipolis, Nice, France
| | - Hind Amghar
- INSERM, U907, Nice, France
- Faculty of Medicine, University of Nice-Sophia Antipolis, Nice, France
| | - Catherine Pons
- Faculty of Medicine, University of Nice-Sophia Antipolis, Nice, France
- Avenir Team, INSERM, U634, Nice, France
| | - Virginie Bourlier
- “Stroma-Vascular Cells of Adipose Tissue” Team, Institute of Metabolic and Cardiovascular Diseases, INSERM, U1048, Toulouse, France
- Université Paul Sabatier, University of Toulouse, Toulouse, France
| | - Jean Galitzky
- “Stroma-Vascular Cells of Adipose Tissue” Team, Institute of Metabolic and Cardiovascular Diseases, INSERM, U1048, Toulouse, France
- Université Paul Sabatier, University of Toulouse, Toulouse, France
| | - Paul A. Grimaldi
- INSERM, U907, Nice, France
- Faculty of Medicine, University of Nice-Sophia Antipolis, Nice, France
| | - Chloé C. Féral
- Faculty of Medicine, University of Nice-Sophia Antipolis, Nice, France
- Avenir Team, INSERM, U634, Nice, France
| | - Anne Bouloumié
- “Stroma-Vascular Cells of Adipose Tissue” Team, Institute of Metabolic and Cardiovascular Diseases, INSERM, U1048, Toulouse, France
- Université Paul Sabatier, University of Toulouse, Toulouse, France
| | - Emmanuel Van Obberghen
- INSERM, U907, Nice, France
- Faculty of Medicine, University of Nice-Sophia Antipolis, Nice, France
- Biochemistry Laboratory, Pasteur Hospital, Nice, France
| | - Jaap G. Neels
- INSERM, U907, Nice, France
- Faculty of Medicine, University of Nice-Sophia Antipolis, Nice, France
- Corresponding author: Jaap G. Neels,
| |
Collapse
|
53
|
Stanke-Labesque F, Pépin JL, de Jouvencel T, Arnaud C, Baguet JP, Petri MH, Tamisier R, Jourdil JF, Lévy P, Bäck M. Leukotriene B4 pathway activation and atherosclerosis in obstructive sleep apnea. J Lipid Res 2012; 53:1944-51. [PMID: 22761257 PMCID: PMC3413233 DOI: 10.1194/jlr.p022814] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 06/20/2012] [Indexed: 11/20/2022] Open
Abstract
Leukotriene B(4) (LTB(4)) production increases in obstructive sleep apnea syndrome (OSA) and is linked to early vascular remodeling, the mechanism of which is unknown. The objective of this study was to to determine the molecular mechanisms of LTB(4) pathway activation in polymorphonuclear cells (PMNs) and early vascular remodeling in OSA and the specific contribution of intermittent hypoxia (IH). PMNs were isolated from 120 OSA patients and 33 healthy subjects and used for measurements of LTB(4) production, determination of mRNA and protein expression levels, or exposed for four cycles of in vitro IH. PMNs derived from OSA patients exhibited increased LTB(4) production, for which apnea-hypopnea index was an independent predictor (P=0.042). 5-Lipoxygenase-activating protein (FLAP) mRNA and protein increased significantly in PMNs from OSA patients versus controls and were associated with carotid luminal diameter and intima-media thickness. LTB(4) (10 ng/ml) increased IL-6 (P=0.006) and MCP-1 (P=0.002) production in OSA patient monocytes. In vitro exposure of PMNs from controls to IH enhanced FLAP mRNA levels (P= 0.027) and induced a 2.7-fold increase (P=0.028) in LTB(4) secretion compared with PMNs exposed to normoxia. In conclusion, upregulation of FLAP in PMNs in response to IH may participate in early vascular remodeling in OSA patients, suggesting FLAP as a potential therapeutic target for the cardiovascular morbidity associated with OSA.
Collapse
Affiliation(s)
- Françoise Stanke-Labesque
- INSERM U1042, Grenoble, F-38042 France
- Université Grenoble 1, Faculté de Médecine, IFR1, Grenoble, F-38042 France
- Laboratoire de pharmacologie, CHU, Hôpital A. Michallon, BP217, Grenoble, F-38043 France
| | - Jean-Louis Pépin
- INSERM U1042, Grenoble, F-38042 France
- Université Grenoble 1, Faculté de Médecine, IFR1, Grenoble, F-38042 France
- Pôle réeducation et Physiologie, CHU, Hôpital A. Michallon, BP217, Grenoble, F-38043 France and
| | - Tiphaine de Jouvencel
- INSERM U698, Paris 7 Denis Diderot University, Bichat University Hospital, 75018 Paris, France
| | | | - Jean-Philippe Baguet
- Université Grenoble 1, Faculté de Médecine, IFR1, Grenoble, F-38042 France
- Clinique de cardiologie, CHU, Hôpital A. Michallon, BP217, Grenoble, F-38043 France
| | - Marcelo H. Petri
- Department of Medicine, Karolinska Institutet, 17176 Stockholm, Sweden; and
| | - Renaud Tamisier
- INSERM U1042, Grenoble, F-38042 France
- Université Grenoble 1, Faculté de Médecine, IFR1, Grenoble, F-38042 France
- Pôle réeducation et Physiologie, CHU, Hôpital A. Michallon, BP217, Grenoble, F-38043 France and
| | - Jean François Jourdil
- Laboratoire de pharmacologie, CHU, Hôpital A. Michallon, BP217, Grenoble, F-38043 France
| | - Patrick Lévy
- INSERM U1042, Grenoble, F-38042 France
- Université Grenoble 1, Faculté de Médecine, IFR1, Grenoble, F-38042 France
- Pôle réeducation et Physiologie, CHU, Hôpital A. Michallon, BP217, Grenoble, F-38043 France and
| | - Magnus Bäck
- INSERM U698, Paris 7 Denis Diderot University, Bichat University Hospital, 75018 Paris, France
- Department of Medicine, Karolinska Institutet, 17176 Stockholm, Sweden; and
- Department of Cardiology, Karolinska University Hospital, CMM L8:03, 17176 Stockholm, Sweden
| |
Collapse
|
54
|
GRICE CHERYLA, FOURIE ANNEM, LEE-DUTRA ALICE. Leukotriene A4 Hydrolase: Biology, Inhibitors and Clinical Applications. ANTI-INFLAMMATORY DRUG DISCOVERY 2012. [DOI: 10.1039/9781849735346-00058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Leukotriene A4 hydrolase is a zinc-containing cytosolic enzyme with both hydrolase and aminopeptidase activity. LTA4H stereospecifically catalyzes the transformation of the unstable epoxide LTA4 to the potent pro-inflammatory mediator LTB4. Variations in the lta4h gene have been linked to susceptibility to multiple diseases including myocardial infarction, stroke and asthma. Pre-clinical animal models and human biomarker data have implicated LTB4 in inflammatory diseases. Several groups have now identified selective inhibitors of LTA4H, many of which were influenced by the disclosure of a protein crystal structure a decade ago. Clinical validation of LTA4H remains elusive despite the progression of inhibitors into pre-clinical and clinical development.
Collapse
Affiliation(s)
- CHERYL A. GRICE
- Johnson & Johnson Pharmaceutical Research & Development, 3210 Merryfield Row, San Diego California 92121 USA
| | - ANNE M. FOURIE
- Johnson & Johnson Pharmaceutical Research & Development, 3210 Merryfield Row, San Diego California 92121 USA
| | - ALICE LEE-DUTRA
- Johnson & Johnson Pharmaceutical Research & Development, 3210 Merryfield Row, San Diego California 92121 USA
| |
Collapse
|
55
|
Riccioni G, Bäck M. Leukotrienes as modifiers of preclinical atherosclerosis? ScientificWorldJournal 2012; 2012:490968. [PMID: 22645425 PMCID: PMC3354776 DOI: 10.1100/2012/490968] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Accepted: 12/15/2011] [Indexed: 12/13/2022] Open
Abstract
Preclinical atherosclerosis represents a crucial period associated with several pathophysiological reactions in the vascular wall. Failure to diagnose preclinical atherosclerosis at this stage misses a major opportunity to prevent the long-term consequences of this disease. Surrogate biological and structural vascular markers are available to determine the presence and the extension of preclinical vascular injury in the general population. Examples of surrogate markers are carotid intima media thickness and biomarkers including high-sensitivity C-reactive protein, cell adhesion molecules and matrix metalloproteinases, and leukotrienes. Recently, leukotrienes have been implicated as mediators, biomarkers, and possible therapeutic targets in the context of subclinical atherosclerosis. The aim of this short paper is to focus on the relation between preclinical atherosclerosis and leukotrienes, with particular attention to the recent development on the use of leukotriene modifiers in the treatment of atherosclerosis.
Collapse
Affiliation(s)
- Graziano Riccioni
- Cardiology Unit, San Camillo de Lellis Hospital, Manfredonia, Foggia, Italy.
| | | |
Collapse
|
56
|
Disruption of the 5-lipoxygenase pathway attenuates atherogenesis consequent to COX-2 deletion in mice. Proc Natl Acad Sci U S A 2012; 109:6727-32. [PMID: 22493243 DOI: 10.1073/pnas.1115313109] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Suppression of cyclooxygenase 2 (COX-2)-derived prostacyclin (PGI(2)) is sufficient to explain most elements of the cardiovascular hazard from nonsteroidal antinflammatory drugs (NSAIDs). However, randomized trials are consistent with the emergence of cardiovascular risk during chronic dosing with NSAIDs. Although deletion of the PGI(2) receptor fosters atherogenesis, the importance of COX-2 during development has constrained the use of conventional knockout (KO) mice to address this question. We developed mice in which COX-2 was deleted postnatally, bypassing cardiorenal defects exhibited by conventional KOs. When crossed into ApoE-deficient hyperlipidemic mice, COX-2 deletion accelerated atherogenesis in both genders, with lesions exhibiting leukocyte infiltration and phenotypic modulation of vascular smooth muscle cells, as reflected by loss of α-smooth muscle cell actin and up-regulation of vascular cell adhesion molecule-1. Stimulated peritoneal macrophages revealed suppression of COX-2-derived prostanoids and augmented 5-lipoxygenase product formation, consistent with COX-2 substrate rediversion. Although deletion of the 5-lipoxygenase activating protein (FLAP) did not influence atherogenesis, it attenuated the proatherogeneic impact of COX-2 deletion in hyperlipidemic mice. Chronic administration of NSAIDs may increasingly confer a cardiovascular hazard on patients at low initial risk. Promotion of atherogenesis by postnatal COX-2 deletion affords a mechanistic explanation for this observation. Coincident inhibition of FLAP may offer an approach to attenuating such a risk from NSAIDs.
Collapse
|
57
|
Capra V, Bäck M, Barbieri SS, Camera M, Tremoli E, Rovati GE. Eicosanoids and Their Drugs in Cardiovascular Diseases: Focus on Atherosclerosis and Stroke. Med Res Rev 2012; 33:364-438. [DOI: 10.1002/med.21251] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Valérie Capra
- Department of Pharmacological Sciences; University of Milan; Via Balzaretti 9 20133 Milan Italy
| | - Magnus Bäck
- Department of Cardiology and Center for Molecular Medicine; Karolinska University Hospital; Stockholm Sweden
| | | | - Marina Camera
- Department of Pharmacological Sciences; University of Milan; Via Balzaretti 9 20133 Milan Italy
- Centro Cardiologico Monzino; I.R.C.C.S Milan Italy
| | - Elena Tremoli
- Department of Pharmacological Sciences; University of Milan; Via Balzaretti 9 20133 Milan Italy
- Centro Cardiologico Monzino; I.R.C.C.S Milan Italy
| | - G. Enrico Rovati
- Department of Pharmacological Sciences; University of Milan; Via Balzaretti 9 20133 Milan Italy
| |
Collapse
|
58
|
Bäck M, Dahlén SE, Drazen JM, Evans JF, Serhan CN, Shimizu T, Yokomizo T, Rovati GE. International Union of Basic and Clinical Pharmacology. LXXXIV: Leukotriene Receptor Nomenclature, Distribution, and Pathophysiological Functions. Pharmacol Rev 2011; 63:539-84. [DOI: 10.1124/pr.110.004184] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
|
59
|
Spite M, Hellmann J, Tang Y, Mathis SP, Kosuri M, Bhatnagar A, Jala VR, Haribabu B. Deficiency of the leukotriene B4 receptor, BLT-1, protects against systemic insulin resistance in diet-induced obesity. THE JOURNAL OF IMMUNOLOGY 2011; 187:1942-9. [PMID: 21742977 DOI: 10.4049/jimmunol.1100196] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Chronic inflammation is an underlying factor linking obesity with insulin resistance. Diet-induced obesity promotes an increase in circulating levels of inflammatory monocytes and their infiltration into expanding adipose tissue. Nevertheless, the endogenous pathways that trigger and sustain chronic low-grade inflammation in obesity are incompletely understood. In this study, we report that a high-fat diet selectively increases the circulating levels of CD11b(+) monocytes in wild-type mice that express leukotriene B(4) receptor, BLT-1, and that this increase is abolished in BLT-1-null mice. The accumulation of classically activated (M1) adipose tissue macrophages (ATMs) and the expression of proinflammatory cytokines and chemokines (i.e., IL-6 and Ccl2) was largely blunted in adipose tissue of obese BLT-1(-/-) mice, whereas the ratio of alternatively activated (M2) ATMs to M1 ATMs was increased. Obese BLT-1(-/-) mice were protected from systemic glucose and insulin intolerance and this was associated with a decrease in inflammation in adipose tissue and liver and a decrease in hepatic triglyceride accumulation. Deletion of BLT-1 prevented high fat-induced loss of insulin signaling in liver and skeletal muscle. These observations elucidate a novel role of chemoattractant receptor, BLT-1, in promoting monocyte trafficking to adipose tissue and promoting chronic inflammation in obesity and could lead to the identification of new therapeutic targets for treating insulin resistance in obesity.
Collapse
Affiliation(s)
- Matthew Spite
- Division of Cardiovascular Medicine, Diabetes and Obesity Center, University of Louisville School of Medicine, Louisville, KY 40202, USA.
| | | | | | | | | | | | | | | |
Collapse
|
60
|
Baek HS, Kim YD, Shin JH, Kim JH, Oh JW, Lee HB. Serum leptin and adiponectin levels correlate with exercise-induced bronchoconstriction in children with asthma. Ann Allergy Asthma Immunol 2011; 107:14-21. [PMID: 21704880 DOI: 10.1016/j.anai.2011.03.013] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 03/15/2011] [Accepted: 03/28/2011] [Indexed: 10/18/2022]
Abstract
BACKGROUND Exercise-induced bronchoconstriction (EIB), a form of bronchial hyperresponsiveness (BHR), is common in children with asthma or obesity. Epidemiological studies have shown that asthma and obesity are increasing in parallel, but obesity- and adipokine-related effects on inflammation and BHR have not yet been demonstrated in the human airway. OBJECTIVE To address the relationship between leptin and adiponectin and EIB in children with asthma. METHODS Eighty-five prepubertal children between the ages of 6 and 10 years were included in our study. They comprised obese with asthma (n = 19), normal weight with asthma (n = 23), obese without asthma (n = 23), and healthy (n = 20). We measured serum leptin and adiponectin levels. We also performed pulmonary function tests: baseline, postbronchodilator inhalation, methacholine inhalation, and exercise. The area under the forced expiratory volume in 1 second (FEV(1))-time curve quantified the severity of EIB over a 20-minute period after exercise (AUC(20)). RESULTS The obese children had significantly elevated levels of leptin and reduced levels of adiponectin. The maximum decreases in %FEV(1) and AUC(20) after exercise were positively correlated with leptin levels and negatively with serum adiponectin levels in children with asthma. The odds for having EIB were incrementally and significantly higher for children with higher levels of serum leptin. CONCLUSIONS Levels of the adipocyte-derived hormones leptin and adiponectin are significantly correlated with BHR induced by exercise challenge in children with asthma. Further studies are needed to elucidate whether the changes in leptin and adiponectin levels bear a causal relationship to the EIB/BHR.
Collapse
Affiliation(s)
- Hey-Sung Baek
- Department of Pediatrics, Hanyang University School of Medicine, 17 Haengdang-Dong, Seoul, Korea
| | | | | | | | | | | |
Collapse
|
61
|
Winnik S, Lohmann C, Richter EK, Schäfer N, Song WL, Leiber F, Mocharla P, Hofmann J, Klingenberg R, Borén J, Becher B, Fitzgerald GA, Lüscher TF, Matter CM, Beer JH. Dietary α-linolenic acid diminishes experimental atherogenesis and restricts T cell-driven inflammation. Eur Heart J 2011; 32:2573-84. [PMID: 21285075 PMCID: PMC3195262 DOI: 10.1093/eurheartj/ehq501] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Aims Epidemiological studies report an inverse association between plant-derived dietary α-linolenic acid (ALA) and cardiovascular events. However, little is known about the mechanism of this protection. We assessed the cellular and molecular mechanisms of dietary ALA (flaxseed) on atherosclerosis in a mouse model. Methods and results Eight-week-old male apolipoprotein E knockout (ApoE−/−) mice were fed a 0.21 % (w/w) cholesterol diet for 16 weeks containing either a high ALA [7.3 % (w/w); n = 10] or low ALA content [0.03 % (w/w); n = 10]. Bioavailability, chain elongation, and fatty acid metabolism were measured by gas chromatography of tissue lysates and urine. Plaques were assessed using immunohistochemistry. T cell proliferation was investigated in primary murine CD3-positive lymphocytes. T cell differentiation and activation was assessed by expression analyses of interferon-γ, interleukin-4, and tumour necrosis factor α (TNFα) using quantitative PCR and ELISA. Dietary ALA increased aortic tissue levels of ALA as well as of the n−3 long chain fatty acids (LC n−3 FA) eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid. The high ALA diet reduced plaque area by 50% and decreased plaque T cell content as well as expression of vascular cell adhesion molecule-1 and TNFα. Both dietary ALA and direct ALA exposure restricted T cell proliferation, differentiation, and inflammatory activity. Dietary ALA shifted prostaglandin and isoprostane formation towards 3-series compounds, potentially contributing to the atheroprotective effects of ALA. Conclusion Dietary ALA diminishes experimental atherogenesis and restricts T cell-driven inflammation, thus providing the proof-of-principle that plant-derived ALA may provide a valuable alternative to marine LC n−3 FA.
Collapse
Affiliation(s)
- Stephan Winnik
- Cardiovascular Research, Institute of Physiology, Zurich University, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
62
|
Chakrabarti SK, Wen Y, Dobrian AD, Cole BK, Ma Q, Pei H, Williams MD, Bevard MH, Vandenhoff GE, Keller SR, Gu J, Nadler JL. Evidence for activation of inflammatory lipoxygenase pathways in visceral adipose tissue of obese Zucker rats. Am J Physiol Endocrinol Metab 2011; 300:E175-87. [PMID: 20978234 PMCID: PMC3023204 DOI: 10.1152/ajpendo.00203.2010] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Central obesity is associated with low-grade inflammation that promotes type 2 diabetes and cardiovascular disease in obese individuals. The 12- and 5-lipoxygenase (12-LO and 5-LO) enzymes have been linked to inflammatory changes, leading to the development of atherosclerosis. 12-LO has also been linked recently to inflammation and insulin resistance in adipocytes. We analyzed the expression of LO and proinflammatory cytokines in adipose tissue and adipocytes in obese Zucker rats, a widely studied genetic model of obesity, insulin resistance, and the metabolic syndrome. mRNA expression of 12-LO, 5-LO, and 5-LO-activating protein (FLAP) was upregulated in adipocytes and adipose tissue from obese Zucker rats compared with those from lean rats. Concomitant with increased LO gene expression, the 12-LO product 12-HETE and the 5-LO products 5-HETE and leukotriene B4 (LTB4) were also increased in adipocytes. Furthermore, upregulation of key proinflammatory markers interleukin (IL)-6, TNFα, and monocyte chemoattractant protein-1 were observed in adipocytes isolated from obese Zucker rats. Immunohistochemistry indicated that the positive 12-LO staining in adipose tissue represents cells in addition to adipocytes. This was confirmed by Western blotting in stromal vascular fractions. These changes were in part reversed by the novel anti-inflammatory drug lisofylline (LSF). LSF also reduced p-STAT4 in visceral adipose tissue from obese Zucker rats and improved the metabolic profile, reducing fasting plasma glucose and increasing insulin sensitivity in obese Zucker rats. In 3T3-L1 adipocytes, LSF abrogated the inflammatory response induced by LO products. Thus, therapeutic agents reducing LO or STAT4 activation may provide novel tools to reduce obesity-induced inflammation.
Collapse
|
63
|
Protection from hepatic lipid accumulation and inflammation by genetic ablation of 5-lipoxygenase. Prostaglandins Other Lipid Mediat 2010; 92:54-61. [PMID: 20227514 DOI: 10.1016/j.prostaglandins.2010.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Revised: 03/01/2010] [Accepted: 03/01/2010] [Indexed: 02/06/2023]
Abstract
Five-lipoxygenase (5-LO) has been postulated as a pathogenic factor in liver injury. Indeed, Alox5, the gene coding for 5-LO, is heavily over-expressed in experimental liver disease, in which 5-LO inhibition consistently ameliorates hepatic steatosis, inflammation and fibrosis. Herein, we report the findings in mice with targeted deletion of Alox5 as a proof of concept of the role of 5-LO in liver injury. Our findings demonstrate that ablation of Alox5 in mice confers protection against carbon tetrachloride-induced liver injury since hepatic necroinflammation, inflammatory infiltrate, hepatocyte ballooning and serum ALT levels were significantly reduced in Alox5-deficient mice. These mice also showed a lower degree of hepatic steatosis, which affected micro- and macrosteatosis to a similar extent. Moreover, microarray analysis revealed a differential profile of hepatic gene expression in Alox5-deficient mice, with a total of 117 genes differentially expressed in these animals. Functional grouping of these genes revealed that 28 (approximately 24% of total changes) were related to the category of lipid metabolism, including the lipogenic factors Lpin1, C/EBP, Fasn, Acly and Elovl6. Moreover, Ingenuity Pathway Analysis revealed lipid metabolism as the molecular/cellular function most affected by the loss of Alox5. These findings confirm at a genetic level that Alox5 plays a pathogenic role in the response of the liver to injury.
Collapse
|
64
|
Horrillo R, González-Périz A, Martínez-Clemente M, López-Parra M, Ferré N, Titos E, Morán-Salvador E, Deulofeu R, Arroyo V, Clària J. 5-lipoxygenase activating protein signals adipose tissue inflammation and lipid dysfunction in experimental obesity. THE JOURNAL OF IMMUNOLOGY 2010; 184:3978-87. [PMID: 20207999 DOI: 10.4049/jimmunol.0901355] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The presence of the so-called low-grade inflammatory state is recognized as a critical event in adipose tissue dysfunction, leading to altered secretion of adipokines and free fatty acids (FFAs), insulin resistance, and development of hepatic complications associated with obesity. This study was designed to investigate the potential contribution of the proinflammatory 5-lipoxygenase (5-LO) pathway to adipose tissue inflammation and lipid dysfunction in experimental obesity. Constitutive expression of key components of the 5-LO pathway, as well as leukotriene (LT) receptors, was detected in adipose tissue as well as in adipocyte and stromal vascular fractions. Adipose tissue from obese mice, compared with that from lean mice, exhibited increased 5-LO activating protein (FLAP) expression and LTB(4) levels. Incubation of adipose tissue with 5-LO products resulted in NF-kappaB activation and augmented secretion of proinflammatory adipokines such as MCP-1, IL-6, and TNF-alpha. In addition, LTB(4), but not LTD(4), reduced FFA uptake in primary adipocytes, whereas 5-LO inhibition suppressed isoproterenol-induced adipose tissue lipolysis. In mice with dietary obesity, elevated FLAP expression in adipose tissue was paralleled with macrophage infiltration, increased circulating FFA levels, and hepatic steatosis, phenomena that were reversed by FLAP inhibition with Bay-X-1005. Interestingly, FLAP inhibition induced AMP-activated protein kinase phosphorylation in parallel with decreases in hormone-sensitive lipase activity and the expression and secretion of TNF-alpha and IL-6. Similar effects were observed in differentiated 3T3-L1 adipocytes incubated with either Bay-X-1005 or the selective LTB(4) receptor antagonist U-75302. Taken together, these findings indicate that the 5-LO pathway signals the adipose tissue low-grade inflammatory state and steatogenic potential in experimental obesity.
Collapse
Affiliation(s)
- Raquel Horrillo
- Department of Biochemistry and Molecular Genetics, Hospital Clinic, August Pi i Sunyer Biomedical Research Institute, Esther Koplowitz Biomedical Research Center, University of Barcelona, Barcelona, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
65
|
Pergola C, Werz O. 5-Lipoxygenase inhibitors: a review of recent developments and patents. Expert Opin Ther Pat 2010; 20:355-75. [DOI: 10.1517/13543771003602012] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
66
|
Iyer A, Fairlie DP, Prins JB, Hammock BD, Brown L. Inflammatory lipid mediators in adipocyte function and obesity. Nat Rev Endocrinol 2010; 6:71-82. [PMID: 20098448 DOI: 10.1038/nrendo.2009.264] [Citation(s) in RCA: 203] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Survival of multicellular organisms depends on their ability to fight infection, metabolize nutrients, and store energy for times of need. Unsurprisingly, therefore, immunoregulatory and metabolic mechanisms interact in human conditions such as obesity. Both infiltrating immunoinflammatory cells and adipocytes play critical roles in the modulation of metabolic homeostasis, so it is important to understand factors that regulate both adipocyte and immune cell function. A currently favored paradigm for obesity-associated metabolic dysfunction is that chronic macronutrient and/or lipid overload (associated with adiposity) induces cellular stress that initiates and perpetuates an inflammatory cycle and pathophysiological signaling of immunoinflammatory cells and adipocytes. Many lipid mediators exert their biological effects by binding to cognate receptors, such as G-protein-coupled receptors and Toll-like receptors. This process is tightly regulated under normal physiological conditions, and any disruption can initiate disease processes. Observations that cellular lipid loading (associated with adiposity) initiates inflammatory events has encouraged studies on the role of lipid mediators. In this review, we speculate that lipid mediators act on important immune receptors to induce low-grade tissue inflammation, which leads to adipocyte and metabolic dysfunction.
Collapse
Affiliation(s)
- Abishek Iyer
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | | | | | | | | |
Collapse
|
67
|
Poeckel D, Funk CD. The 5-lipoxygenase/leukotriene pathway in preclinical models of cardiovascular disease. Cardiovasc Res 2010; 86:243-53. [PMID: 20093252 DOI: 10.1093/cvr/cvq016] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Leukotrienes (LTs) derived from 5-lipoxygenase (5-LO) activity are most widely known for their actions during acute inflammation and asthma. 5-LO/LT pathway involvement in cardiovascular disease (CVD) pathogenesis has come to the forefront based on provocative human genetic/population and animal studies leading to the hypothesis that this pathway promotes atherosclerosis, abdominal aortic aneurysm, and myocardial infarction/reperfusion injury via increased leucocyte chemotaxis, vascular inflammation and enhanced permeability, and subsequent tissue/matrix degeneration. A series of pre-clinical studies have tested this hypothesis by means of genetic or pharmacological inhibition of either the LT biosynthesis axis (5-LO, 5-LO-activating protein, LTA(4) hydrolase, LTC(4) synthase) or the cognate LT receptors. Here, we summarize, compare, and analyse these animal studies and relate their findings to human disease pathogenesis. We draw a complex picture of 5-LO/LT participation in cardiovascular disorders, which is further complicated by marked differences between species. Moreover, we discuss how the cytokine footprint of the respective pathological conditions determines the expression level and hence, the contribution of components of the pathway to the overall disease state. Current knowledge implies a role for 5-LO and LTs during the early/acute phase of CVD, but our understanding of a putative 5-LO/LT involvement in more advanced stages of CVD is limited, thereby preventing simple extrapolation of findings from animal studies to humans.
Collapse
Affiliation(s)
- Daniel Poeckel
- Department of Physiology, Queen's University, 433 Botterell Hall, Kingston, ON, Canada K7L 3N6
| | | |
Collapse
|
68
|
Inhibition of soluble epoxide hydrolase enhances the anti-inflammatory effects of aspirin and 5-lipoxygenase activation protein inhibitor in a murine model. Biochem Pharmacol 2009; 79:880-7. [PMID: 19896470 DOI: 10.1016/j.bcp.2009.10.025] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 10/24/2009] [Accepted: 10/26/2009] [Indexed: 11/21/2022]
Abstract
Inflammation is a multi-staged process whose expansive phase is thought to be driven by acutely released arachidonic acid (AA) and its metabolites. Inhibition of cyclooxygenase (COX), lipoxygenase (LOX), or soluble epoxide hydrolase (sEH) is known to be anti-inflammatory. Inhibition of sEH stabilizes the cytochrome P450 (CYP450) products epoxyeicosatrienoic acids (EETs). Here we used a non-selective COX inhibitor aspirin, a 5-lipoxygenase activation protein (FLAP) inhibitor MK886, and a sEH inhibitor t-AUCB to selectively modulate the branches of AA metabolism in a lipopolysaccharide (LPS)-challenged murine model. We used metabolomic profiling to simultaneously monitor representative AA metabolites of each branch. In addition to the significant crosstalk among branches of the AA cascade during selective modulation of COX, LOX, or sEH, we demonstrated that co-administration of t-AUCB enhanced the anti-inflammatory effects of aspirin or MK886, which was evidenced by the observations that co-administration resulted in favorable eicosanoid profiles and better control of LPS-mediated hypotension as well as hepatic protein expression of COX-2 and 5-LOX. Targeted disruption of the sEH gene displayed a parallel profile to that produced by t-AUCB. These observations demonstrate a significant level of crosstalk among the three major branches of the AA cascade and that they are not simply parallel pathways. These data illustrate that inhibition of sEH by both pharmacological intervention and gene knockout enhances the anti-inflammatory effects of aspirin and MK886, suggesting the possibility of modulating multiple branches to achieve better therapeutic effects.
Collapse
|
69
|
Stanke-Labesque F, Bäck M, Lefebvre B, Tamisier R, Baguet JP, Arnol N, Lévy P, Pépin JL. Increased urinary leukotriene E4 excretion in obstructive sleep apnea: effects of obesity and hypoxia. J Allergy Clin Immunol 2009; 124:364-70, 370.e1-2. [PMID: 19596146 DOI: 10.1016/j.jaci.2009.05.033] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Revised: 04/08/2009] [Accepted: 05/19/2009] [Indexed: 11/26/2022]
Abstract
BACKGROUND Low-grade inflammation may potentially explain the relationship between obstructive sleep apnea syndrome (OSA) and cardiovascular events. However, the respective contribution of intermittent hypoxia and confounders, such as obesity, is still debated. OBJECTIVES To monitor urinary leukotriene E(4) (U-LTE(4)), a validated marker of proinflammatory cysteinyl leukotriene production, in OSA; to determine the influence of obesity and other confounders on U-LTE(4) concentrations; to examine the mechanisms involved through transcriptional profiling of the leukotriene pathway in peripheral blood mononuclear cells (PBMCs); and to investigate the effect of continuous positive air pressure (CPAP) on U-LTE(4) concentrations. METHODS We measured U-LTE(4) by liquid chromatography-tandem mass spectrometry. RESULTS The U-LTE(4) concentrations were increased (P = .019) in 40 nonobese patients with OSA carefully matched for age, sex, and body mass index (BMI) to 25 control subjects, and correlated (r = 0.0312; P = .017) to the percentage of time spent with mean oxygen saturation (SaO(2)) less than 90%. In a larger cohort of patients with OSA (n = 72), U-LTE(4) increased as a function of BMI (r = 0.445; P = .0002). In those patients, the expression levels of 5-lipoxygenase activating protein mRNA in mononuclear cells exhibited a similar pattern. A stepwise multiple linear regression analysis performed in this cohort identified BMI (P = .001; regression coefficient, 3.33) and percentage of time spent with SaO(2) <90% (P = .001; regression coefficient, 1.01) as independent predictors of U-LTE(4) concentrations. Compared with baseline, CPAP reduced by 22% (P = .006) U-LTE(4) concentrations only in patients with OSA with normal BMI. CONCLUSION Obesity, and to a lesser extent hypoxia severity, are determinant of U-LTE(4) production in patients with OSA.
Collapse
|
70
|
Seo KW, Lee SJ, Kim CE, Yun MR, Park HM, Yun JW, Bae SS, Kim CD. Participation of 5-lipoxygenase-derived LTB(4) in 4-hydroxynonenal-enhanced MMP-2 production in vascular smooth muscle cells. Atherosclerosis 2009; 208:56-61. [PMID: 19586628 DOI: 10.1016/j.atherosclerosis.2009.06.012] [Citation(s) in RCA: 215] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Revised: 06/05/2009] [Accepted: 06/08/2009] [Indexed: 11/16/2022]
Abstract
5-Lipoxygenase (5-LO) has been suggested as a modulator of atherosclerotic plaque instability, however, its role in MMP production in vascular smooth muscle cells (VSMC) is still unclear. Thus, this study investigated the role of 5-LO in HNE-enhanced MMP-2 production in VSMC, and the mechanisms by which this enzyme could be activated by HNE. VSMC stimulated with HNE (1 microM) produced MMP-2, which was markedly attenuated in 5-LO-deficient VSMC as well as in cells pretreated with a FLAP inhibitor, MK886, confirming a role for 5-LO metabolites in HNE-enhanced MMP-2 production. Related to these results, HNE increased nuclear translocation of 5-LO promoting 5-LO activity, which was attenuated not only by SB203580, a p38 MAPK inhibitor, but also by PD98059, an ERK inhibitor. In parallel, phosphorylation of p38 MAPK and ERK occurred as early as 15 min after exposure to HNE, suggesting a potential role for p38 MAPK and ERK pathways in HNE-induced activation of 5-LO. Among leukotriene (LT) receptor antagonists, U-75302, a BLT receptor antagonist, but not MK-571 and Rev-5901, cysLT receptor antagonists, showed an inhibitory effect on HNE-enhanced MMP-2 production. Moreover, MMP-2 production in VSMC was also significantly increased by LTB(4), but not by LTC(4) and LTD(4). Collectively, these data suggest that 5-LO mediates HNE-enhanced MMP-2 production via LTB(4)-BLT receptor pathways, consequently leading to atherosclerotic plaque instability.
Collapse
Affiliation(s)
- Kyo W Seo
- MRC for Ischemic Tissue Regeneration and Medical Research Institute, Pusan National University, Yangsan, Gyeongnam, Republic of Korea
| | | | | | | | | | | | | | | |
Collapse
|
71
|
Hlawaty H, Jacob MP, Louedec L, Letourneur D, Brink C, Michel JB, Feldman L, Bäck M. Leukotriene Receptor Antagonism and the Prevention of Extracellular Matrix Degradation During Atherosclerosis and In-Stent Stenosis. Arterioscler Thromb Vasc Biol 2009; 29:518-24. [DOI: 10.1161/atvbaha.108.181750] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Hanna Hlawaty
- From the INSERM U698 (H.H., M.-P.J., L.L., D.L., C.B., J.-B.M., L.F., M.B.), University of Paris 13 (H.H., D.L.), University of Paris 7 (M.-P.J., C.B., J.-B.M., L.F.), and the Department of Cardiology (L.F., M.B.), Bichat Hospital, Paris, France; and the Center for Molecular Medicine (M.B.), Karolinska University Hospital, Stockholm, Sweden
| | - Marie-Paule Jacob
- From the INSERM U698 (H.H., M.-P.J., L.L., D.L., C.B., J.-B.M., L.F., M.B.), University of Paris 13 (H.H., D.L.), University of Paris 7 (M.-P.J., C.B., J.-B.M., L.F.), and the Department of Cardiology (L.F., M.B.), Bichat Hospital, Paris, France; and the Center for Molecular Medicine (M.B.), Karolinska University Hospital, Stockholm, Sweden
| | - Liliane Louedec
- From the INSERM U698 (H.H., M.-P.J., L.L., D.L., C.B., J.-B.M., L.F., M.B.), University of Paris 13 (H.H., D.L.), University of Paris 7 (M.-P.J., C.B., J.-B.M., L.F.), and the Department of Cardiology (L.F., M.B.), Bichat Hospital, Paris, France; and the Center for Molecular Medicine (M.B.), Karolinska University Hospital, Stockholm, Sweden
| | - Didier Letourneur
- From the INSERM U698 (H.H., M.-P.J., L.L., D.L., C.B., J.-B.M., L.F., M.B.), University of Paris 13 (H.H., D.L.), University of Paris 7 (M.-P.J., C.B., J.-B.M., L.F.), and the Department of Cardiology (L.F., M.B.), Bichat Hospital, Paris, France; and the Center for Molecular Medicine (M.B.), Karolinska University Hospital, Stockholm, Sweden
| | - Charles Brink
- From the INSERM U698 (H.H., M.-P.J., L.L., D.L., C.B., J.-B.M., L.F., M.B.), University of Paris 13 (H.H., D.L.), University of Paris 7 (M.-P.J., C.B., J.-B.M., L.F.), and the Department of Cardiology (L.F., M.B.), Bichat Hospital, Paris, France; and the Center for Molecular Medicine (M.B.), Karolinska University Hospital, Stockholm, Sweden
| | - Jean-Baptiste Michel
- From the INSERM U698 (H.H., M.-P.J., L.L., D.L., C.B., J.-B.M., L.F., M.B.), University of Paris 13 (H.H., D.L.), University of Paris 7 (M.-P.J., C.B., J.-B.M., L.F.), and the Department of Cardiology (L.F., M.B.), Bichat Hospital, Paris, France; and the Center for Molecular Medicine (M.B.), Karolinska University Hospital, Stockholm, Sweden
| | - Laurent Feldman
- From the INSERM U698 (H.H., M.-P.J., L.L., D.L., C.B., J.-B.M., L.F., M.B.), University of Paris 13 (H.H., D.L.), University of Paris 7 (M.-P.J., C.B., J.-B.M., L.F.), and the Department of Cardiology (L.F., M.B.), Bichat Hospital, Paris, France; and the Center for Molecular Medicine (M.B.), Karolinska University Hospital, Stockholm, Sweden
| | - Magnus Bäck
- From the INSERM U698 (H.H., M.-P.J., L.L., D.L., C.B., J.-B.M., L.F., M.B.), University of Paris 13 (H.H., D.L.), University of Paris 7 (M.-P.J., C.B., J.-B.M., L.F.), and the Department of Cardiology (L.F., M.B.), Bichat Hospital, Paris, France; and the Center for Molecular Medicine (M.B.), Karolinska University Hospital, Stockholm, Sweden
| |
Collapse
|
72
|
Sultan A, Strodthoff D, Robertson AK, Paulsson-Berne G, Fauconnier J, Parini P, Rydén M, Thierry-Mieg N, Johansson ME, Chibalin AV, Zierath JR, Arner P, Hansson GK. T cell-mediated inflammation in adipose tissue does not cause insulin resistance in hyperlipidemic mice. Circ Res 2009; 104:961-8. [PMID: 19299644 DOI: 10.1161/circresaha.108.190280] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Obesity is associated with chronic inflammation in adipose tissue. Proinflammatory cytokines including tumor necrosis factor-alpha and interleukin-6 secreted by adipose tissue during the metabolic syndrome are proposed to cause local and general insulin resistance and promote development of type 2 diabetes. We have used a compound mutant mouse, Apoe(-/-)xCD4dnTGFbR, with dysregulation of T-cell activation, excessive production of proinflammatory cytokines, hyperlipidemia, and atherosclerosis, to dissect the role of inflammation in adipose tissue metabolism. These mice are lean, which avoids confounding effects of concomitant obesity. Expression and secretion of a set of proinflammatory factors including tumor necrosis factor-alpha, interferon-gamma, and monocyte chemoattractant protein-1 was increased in adipose tissue of Apoe(-/-)xCD4dnTGFbR mice, as was the enzyme 11beta-hydroxysteroid dehydrogenase type 1, which converts cortisone to bioactive cortisol. Interleukin-6, which has an inhibitory glucocorticoid response element in its promoter, was not upregulated. In spite of intense local inflammation, insulin sensitivity was not impaired in adipose tissue of Apoe(-/-)xCD4dnTGFbR mice unless exogenous interleukin-6 was administered. In conclusion, T-cell activation causes inflammation in adipose tissue but does not lead to insulin resistance in this tissue in the absence of interleukin-6.
Collapse
Affiliation(s)
- Ariane Sultan
- Department of Medicine, Center for Molecular Medicine, Karolinska University Hospital, Stockholm, Sweden
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
73
|
Houard X, Ollivier V, Louedec L, Michel J, Back M. Differential inflammatory activity across human abdominal aortic aneurysms reveals neutrophilderived leukotriene B4 as a major chemotactic factor released from the intraluminal thrombus. FASEB J 2009; 23:1376-83. [DOI: 10.1096/fj.08-116202] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Xavier Houard
- INSERM U698 Paris 7 Denis Diderot UniversityCardiovascular HematologyBio‐Engineering and RemodelingBichat‐Claude Bernard HospitalParisFrance
| | - Veronique Ollivier
- INSERM U698 Paris 7 Denis Diderot UniversityCardiovascular HematologyBio‐Engineering and RemodelingBichat‐Claude Bernard HospitalParisFrance
| | - Liliane Louedec
- INSERM U698 Paris 7 Denis Diderot UniversityCardiovascular HematologyBio‐Engineering and RemodelingBichat‐Claude Bernard HospitalParisFrance
| | - Jean‐Baptiste Michel
- INSERM U698 Paris 7 Denis Diderot UniversityCardiovascular HematologyBio‐Engineering and RemodelingBichat‐Claude Bernard HospitalParisFrance
| | - Magnus Back
- INSERM U698 Paris 7 Denis Diderot UniversityCardiovascular HematologyBio‐Engineering and RemodelingBichat‐Claude Bernard HospitalParisFrance
- Department of Cardiology and Center for Molecular MedicineKarolinska University HospitalStockholmSweden
| |
Collapse
|
74
|
Bäck M. Leukotriene signaling in atherosclerosis and ischemia. Cardiovasc Drugs Ther 2008; 23:41-8. [PMID: 18949546 DOI: 10.1007/s10557-008-6140-9] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2008] [Accepted: 09/18/2008] [Indexed: 01/07/2023]
Abstract
INTRODUCTION The inflammatory process of atherosclerosis is associated with several pathophysiological reactions within the vascular wall. The arachidonic acid released by phospholipase A(2) serves as substrate for the production of a group of lipid mediators known as the leukotrienes, which induce pro-inflammatory signaling through activation of specific BLT and CysLT receptors. DISCUSSION Leukotriene signaling has been implicated in early lipid retention and foam cell accumulation, as well as in the development of intimal hyperplasia and advanced atherosclerotic lesions. Furthermore, the association of leukotrienes with degradation of extracellular matrix has suggested a role in atherosclerotic plaque rupture. Finally, studies of either myocardial or cerebral ischemia and reperfusion indicate that leukotriene signaling in addition may be involved in the development of ischemic injury. CONCLUSION Both leukotriene synthesis inhibitors and leukotriene receptor antagonists have been suggested to induce beneficial effects at different stages of the atherosclerosis process.
Collapse
Affiliation(s)
- Magnus Bäck
- INSERM U698, Bichat Hospital, 46 rue Henri Huchard, 75018, Paris, France.
| |
Collapse
|
75
|
Bibliography. Current world literature. Atherosclerosis: cell biology and lipoproteins. Curr Opin Lipidol 2008; 19:525-35. [PMID: 18769235 DOI: 10.1097/mol.0b013e328312bffc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
76
|
Cao RY, St Amand T, Gräbner R, Habenicht AJR, Funk CD. Genetic and pharmacological inhibition of the 5-lipoxygenase/leukotriene pathway in atherosclerotic lesion development in ApoE deficient mice. Atherosclerosis 2008; 203:395-400. [PMID: 18804760 DOI: 10.1016/j.atherosclerosis.2008.07.045] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Revised: 07/25/2008] [Accepted: 07/28/2008] [Indexed: 11/29/2022]
Abstract
The 5-lipoxygenase (5-LO) catalyzed formation of leukotriene (LT) lipid mediators is a pathway contributing to inflammatory events in asthma and more recently has been associated with cardiovascular disease. However, the relative impact of this pathway in atherogenesis has been controversial and a variety of mixed results reported. The goal of these studies was to assess the importance of the 5-LO/LT pathway in mice with either genetic (5-LO(-/-)) or pharmacological (L-739,010) inhibition of the 5-LO pathway on an apolipoprotein E deficient (apoE(-/-)) background when subjected to either an 8-week (Paigen) or 6 months (Western) atherosclerotic diet regimen. Atherosclerotic lesion analysis at the aortic root, brachiocephalic artery and throughout the whole aorta by en face Sudan IV staining was determined, as well as blood lipid levels. Ex vivo calcium ionophore-stimulation of whole blood demonstrated a significant reduction in the capacity to form LTB(4) in 5-LO(-/-) and drug-treated 5-LO(+/+) mice. Quantitative analysis of atherosclerotic lesions did not differ between groups at all three sites. Moreover, the composition of advanced lesions in the brachiocephalic arteries did not indicate altered plaque disruption as a result of 5-LO gene inactivation. These results do not support a role for the 5-LO/LT pathway in intermediate to advanced atherosclerotic lesion development in mice.
Collapse
Affiliation(s)
- Richard Yang Cao
- Department of Physiology, Queen's University, Kingston, ON, Canada
| | | | | | | | | |
Collapse
|
77
|
Effects of Retinoic Acid on Differentiation and Gene Expression of Pig Preadipocytes. JOURNAL OF ANIMAL SCIENCE AND TECHNOLOGY 2008. [DOI: 10.5187/jast.2008.50.4.475] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
78
|
López-Parra M, Titos E, Horrillo R, Ferré N, González-Périz A, Martínez-Clemente M, Planagumà A, Masferrer J, Arroyo V, Clària J. Regulatory effects of arachidonate 5-lipoxygenase on hepatic microsomal TG transfer protein activity and VLDL-triglyceride and apoB secretion in obese mice. J Lipid Res 2008; 49:2513-23. [PMID: 18645210 DOI: 10.1194/jlr.m800101-jlr200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
As 5-lipoxygenase (5-LO) is an emerging target in obesity and insulin resistance, we have investigated whether this arachidonate pathway is also implicated in the progression of obesity-related fatty liver disease. Our results show that 5-LO activity and 5-LO-derived product levels are significantly elevated in the liver of obese ob/ob mice with respect to wild-type controls. Treatment of ob/ob mice with a selective 5-LO inhibitor exerted a remarkable protection from hepatic steatosis as revealed by decreased oil red-O staining and reduced hepatic triglyceride (TG) concentrations. In addition, 5-LO inhibition in ob/ob mice downregulated genes involved in hepatic fatty acid uptake (i.e., L-FABP and FAT/CD36) and normalized peroxisome proliferator-activated receptor alpha (PPARalpha) and acyl-CoA oxidase expression, whereas the expression of lipogenic genes [i.e., fatty acid synthase (FASN) and SREBP-1c] remained unaltered. Furthermore, 5-LO inhibition restored hepatic microsomal TG transfer protein (MTP) activity in parallel with a stimulation of hepatic VLDL-TG and apoB secretion in ob/ob mice. Consistent with these findings, 5-LO products directly inhibited MTP activity and triggered cytosolic TG accumulation in CC-1 cells, a murine hepatocyte cell line. Taken together, these findings identify a novel steatogenic role for 5-LO in the liver through mechanisms involving the regulation of hepatic MTP activity and VLDL-TG and apoB secretion.
Collapse
Affiliation(s)
- Marta López-Parra
- Department of Biochemistry and Molecular Genetics, Centro de Investigación Biomédica Esther Koplowitz (CIBEK), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona 08036, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
79
|
Abstract
Individuals with type 2 diabetes mellitus have increased cardiovascular disease risk compared with those without diabetes. Treatment of the residual risk, other than blood pressure and LDL-cholesterol control, remains important as the rate of diabetes increases worldwide. The accelerated atherosclerosis and cardiovascular disease in diabetes is likely to be multifactorial and therefore several therapeutic approaches can be considered. Results of mechanistic studies done in vitro and in vivo--animals and people--can provide important insights with the potential to improve clinical management decisions and outcomes. In this Review, we focus on three areas in which pathophysiological considerations could be particularly informative--ie, the roles of hyperglycaemia, diabetic dyslipidaemia (other than the control of LDL-cholesterol concentrations), and inflammation (including that in adipose tissue) in the acceleration of vascular injury.
Collapse
Affiliation(s)
- Theodore Mazzone
- Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA.
| | | | | |
Collapse
|
80
|
Bäck M. Inflammatory signaling through leukotriene receptors in atherosclerosis. Curr Atheroscler Rep 2008; 10:244-51. [DOI: 10.1007/s11883-008-0038-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
81
|
Suckling K. The landscape of drug discovery in atherosclerosis and dyslipidaemia: a survey from patenting activity. Expert Opin Ther Pat 2008. [DOI: 10.1517/13543776.18.5.473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
82
|
Whatling C, McPheat W, Herslöf M. The potential link between atherosclerosis and the 5-lipoxygenase pathway: investigational agents with new implications for the cardiovascular field. Expert Opin Investig Drugs 2008; 16:1879-93. [PMID: 18041998 DOI: 10.1517/13543784.16.12.1879] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The 5-lipoxygenase pathway is responsible for the production of leukotrienes--inflammatory lipid mediators that have a role in innate immunity, but that can also have pathological effects in inflammatory diseases. Recently, a potential link between leukotriene production and atherosclerosis has been proposed. The expression of leukotriene biosynthetic enzymes and leukotriene receptors has been identified in coronary and carotid atherosclerotic plaques, and the levels of biosynthetic enzymes have been correlated with the clinical symptoms of unstable plaques. Genetic variants in 5-lipoxygenase pathway genes have also been associated with a relative risk of developing myocardial infarction and stroke. On the basis of these discoveries, antileukotriene compounds are now being evaluated for the treatment of cardiovascular disease. Several tool compounds have been shown to limit the progression of lesion development in preclinical models of atherosclerosis, and three compounds, including two drugs previously developed for asthma, are undergoing clinical trials in patients with acute coronary syndromes.
Collapse
Affiliation(s)
- Carl Whatling
- AstraZeneca R&D Mölndal, Bioscience Department, Pepparedsleden 1, 431 83 Mölndal, Sweden.
| | | | | |
Collapse
|
83
|
Tiwari R, Singh V, Barthwal M. Macrophages: An elusive yet emerging therapeutic target of atherosclerosis. Med Res Rev 2008; 28:483-544. [DOI: 10.1002/med.20118] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
84
|
Abstract
Inflammation underpins the development of atherosclerosis. Initiation and progression of vascular inflammation involves a complex cellular network, with macrophages as major contributors. Activated macrophages produce proinflammatory mediators, bridge innate and adaptive immunity, regulate lipid retention, and participate directly in vascular repair and remodeling. Recent efforts to elucidate molecular mechanisms involved in the regulation of vascular inflammation in atherosclerosis have implicated several families of innate immune recognition receptors in inflammatory activation during the course of this disease. This article reviews our current understanding of innate immune recognition receptors, signaling pathways, and putative ligands implicated in activation of macrophages in the disease. In its final section, we propose a model for the role of macrophages in bridging inflammation and atherosclerosis from the perspective of innate immune recognition and activation.
Collapse
Affiliation(s)
- Zhong-qun Yan
- Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden.
| | | |
Collapse
|
85
|
Johnston RA, Zhu M, Rivera-Sanchez YM, Lu FL, Theman TA, Flynt L, Shore SA. Allergic airway responses in obese mice. Am J Respir Crit Care Med 2007; 176:650-8. [PMID: 17641156 PMCID: PMC1994235 DOI: 10.1164/rccm.200702-323oc] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2007] [Accepted: 07/16/2007] [Indexed: 01/13/2023] Open
Abstract
RATIONALE Epidemiologic data indicate an increased incidence of asthma in the obese. OBJECTIVES To determine whether obese mice exhibit augmented pulmonary responses after allergen sensitization and challenge. METHODS Lean, wild-type (C57BL/6), obese ob/ob, and obese db/db mice were sensitized to ovalbumin (OVA), and then challenged with aerosolized OVA or phosphate-buffered saline (PBS). Changes in total pulmonary resistance (Rl) induced by intravenous methacholine were measured by forced oscillation. Blood was collected, bronchoalveolar lavage (BAL) was performed, and lungs were harvested for measurement of cytokine expression by real-time reverse transcription-polymerase chain reaction. MEASUREMENTS AND MAIN RESULTS OVA challenge increased baseline Rl in ob/ob, but not wild-type, mice, and airway responsiveness was greater in ob/ob than wild-type mice, regardless of the challenge. Compared with PBS, OVA challenge caused an increase in the number of BAL fluid (BALF) cells, an increase in lung Th2 cytokine expression, and an increase in serum IgE. Significantly fewer BALF cells were recovered from OVA-challenged ob/ob versus wild-type mice, whereas serum IgE levels were elevated significantly more in ob/ob versus wild-type mice. BALF and lung Th2 cytokine expression was not different in ob/ob versus wild-type mice. Airway responsiveness was greater in db/db versus wild-type mice, regardless of the challenge, and OVA caused airway hyperresponsiveness in db/db but not wild-type mice, despite reduced BALF cells in OVA-challenged db/db versus wild-type mice. CONCLUSIONS These results demonstrate that obesity enhances OVA-induced changes in pulmonary resistance and serum IgE and that these changes are not the result of increased Th2 type airway inflammation.
Collapse
Affiliation(s)
- Richard A Johnston
- Molecular and Integrative Physiological Sciences Program, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA.
| | | | | | | | | | | | | |
Collapse
|