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Sabbir MG, Wigle JT, Taylor CG, Zahradka P. Growth State-Dependent Expression of Arachidonate Lipoxygenases in the Human Endothelial Cell Line EA.hy926. Cells 2022; 11:cells11162478. [PMID: 36010555 PMCID: PMC9406857 DOI: 10.3390/cells11162478] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 08/05/2022] [Accepted: 08/07/2022] [Indexed: 11/30/2022] Open
Abstract
Endothelial cells regulate vascular homeostasis through the secretion of various paracrine molecules, including bioactive lipids, but little is known regarding the enzymes responsible for generating these lipids under either physiological or pathophysiological conditions. Arachidonate lipoxygenase (ALOX) expression was therefore investigated in confluent and nonconfluent EA.h926 endothelial cells, which represent the normal quiescent and proliferative states, respectively. mRNAs for ALOX15, ALOX15B, and ALOXE3 were detected in EA.hy926 cells, with the highest levels present in confluent cells compared to nonconfluent cells. In contrast, ALOX5, ALOX12, and ALOX12B mRNAs were not detected. At the protein level, only ALOX15B and ALOXE3 were detected but only in confluent cells. ALOXE3 was also observed in confluent human umbilical artery endothelial cells (HUAEC), indicating that its expression, although previously unreported, may be a general feature of endothelial cells. Exposure to laminar flow further increased ALOXE3 levels in EA.hy926 cells and HUAECs. The evidence obtained in this study indicates that proliferative status and shear stress are both important factors that mediate endothelial ALOX gene expression. The presence of ALOX15B and ALOXE3 exclusively in quiescent human endothelial cells suggests their activity likely contributes to the maintenance of a healthy endothelium.
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Affiliation(s)
- Mohammad G. Sabbir
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Jeffrey T. Wigle
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Carla G. Taylor
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
- Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Peter Zahradka
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
- Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
- Correspondence: ; Tel.: +204-235-3507; Fax: +204-237-4018
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Chen S, Zou H. Key Role of 12-Lipoxygenase and Its Metabolite 12-Hydroxyeicosatetraenoic Acid (12-HETE) in Diabetic Retinopathy. Curr Eye Res 2022; 47:329-335. [PMID: 35129022 DOI: 10.1080/02713683.2021.1995003] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE Abnormal lipid metabolism has been proved to be implicated in the complex pathogenesis of diabetic retinopathy (DR). 12-lipoxygenase (12-LOX) is a member of lipoxygenase family responsible for the oxygenation of cellular polyunsaturated fatty acids to produce lipid mediators which modulate cell inflammation. This review explores the role of 12-lipoxygenase and its products in the pathogenesis of DR. METHODS A comprehensive medical literature search was conducted on PubMed till September 2021. RESULTS Emerging evidence has demonstrated that 12-LOX and its main product 12- hydroxyeicosatetraenoic acid (12-HETE) activate retinal cells, especially retinal vascular endothelial cells, through the activation of NADPH oxidase and the subsequent generation of reactive oxygen species (ROS), mediating multiple pathological changes during DR. Genetic deletion or pharmacological inhibition models of 12-LOX in mice show protection from DR. CONCLUSION 12-LOX and its product 12-HETE take important part in DR pathogenesis and show their potential as future therapeutic targets for DR. Further studies are needed on the specific mechanism including 12-LOX pathway related molecules, 12-HETE receptors and downstream signaling pathways.
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Affiliation(s)
- Shuli Chen
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Haidong Zou
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Eye Disease Prevention and Treatment Center, Shanghai Eye Hospital, Shanghai, China.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
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Piper K, Garelnabi M. Eicosanoids: Atherosclerosis and cardiometabolic health. J Clin Transl Endocrinol 2020; 19:100216. [PMID: 32071878 PMCID: PMC7013337 DOI: 10.1016/j.jcte.2020.100216] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 01/22/2020] [Accepted: 02/01/2020] [Indexed: 02/08/2023] Open
Abstract
Cardiovascular diseases (CVD) have been the leading causes of death in the U.S. for nearly a century. Numerous studies have linked eicosanoids to cardiometabolic disease. Objectives and Methods: This review summaries recent advances and innovative research in eicosanoids and CVD. Numerous review articles and their original human or animal studies were assessed in the relevant and recent studies. OUTCOME We identified and discussed recent trends in eicosanoids known for their roles in CVD. Their subsequent relationships were assessed for any possible implications associated with consumption of different dietary lipids, essentially omega fatty acids. Eicosanoids have been heavily sought after over recent decades for their direct role in mediating the enhancement and resolution of acute immune responses. Given the short half-life of these oxidized lipid metabolites, studies on atherosclerosis have had to rely on the metabolites that are actively involved in eicosanoid production, signaling or redox reactions as markers for atherosclerosis-related molecular behaviors. CONCLUSION Further investigations expending current knowledge, should be applied to narrow the specific class and species of eicosanoids responsible for inciting inflammation especially in the context of recent clinical studies assessing the role of dietary lipid in cardiovascular diseases.
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Peroxiredoxin III Protects Tumor Suppressor PTEN from Oxidation by 15-Hydroperoxy-eicosatetraenoic Acid. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:2828493. [PMID: 31636803 PMCID: PMC6766106 DOI: 10.1155/2019/2828493] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 06/24/2019] [Accepted: 08/25/2019] [Indexed: 01/21/2023]
Abstract
Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a lipid and protein phosphatase that coordinates various cellular processes. Its activity is regulated by the reversible oxidation of an active-site cysteine residue by H2O2 and thioredoxin. However, the potential role of lipid peroxides in the redox regulation of PTEN remains obscure. To evaluate this, 15-hydroperoxy-eicosatetraenoic acid (15s-HpETE), a lipid peroxide, was employed to investigate its effect on PTEN using molecular and cellular-based assays. Exposure to 15s-HpETE resulted in the oxidation of recombinant PTEN. Reversible oxidation of PTEN was also observed in mouse embryonic fibroblast (MEF) cells treated with a 15s-HpETE and Lipofectamine mixture. The oxidative dimerization of thioredoxin was found simultaneously. In addition, the absence of peroxiredoxin III aggravated 15s-HpETE-induced PTEN oxidation in MEF cells. Our study provides novel insight into the mechanism linking lipid peroxidation to the etiology of tumorigenesis.
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Singh NK, Rao GN. Emerging role of 12/15-Lipoxygenase (ALOX15) in human pathologies. Prog Lipid Res 2019; 73:28-45. [PMID: 30472260 PMCID: PMC6338518 DOI: 10.1016/j.plipres.2018.11.001] [Citation(s) in RCA: 170] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 11/07/2018] [Accepted: 11/09/2018] [Indexed: 02/06/2023]
Abstract
12/15-lipoxygenase (12/15-LOX) is an enzyme, which oxidizes polyunsaturated fatty acids, particularly omega-6 and -3 fatty acids, to generate a number of bioactive lipid metabolites. A large number of studies have revealed the importance of 12/15-LOX role in oxidative and inflammatory responses. The in vitro studies have demonstrated the ability of 12/15-LOX metabolites in the expression of various genes and production of cytokine related to inflammation and resolution of inflammation. The studies with the use of knockout and transgenic animals for 12/15-LOX have further shown its involvement in the pathogenesis of a variety of human diseases, including cardiovascular, renal, neurological and metabolic disorders. This review summarizes our current knowledge on the role of 12/15-LOX in inflammation and various human diseases.
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Affiliation(s)
- Nikhlesh K Singh
- Department of Physiology, University of Tennessee Health Science Center, 71 S. Manassas Street Memphis, Memphis, TN 38163, USA
| | - Gadiparthi N Rao
- Department of Physiology, University of Tennessee Health Science Center, 71 S. Manassas Street Memphis, Memphis, TN 38163, USA.
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Zhang C, Ma C, Yao H, Zhang L, Yu X, Liu Y, Shen T, Zhang L, Zhang F, Chen X, Zhu D. 12-Lipoxygenase and 12-hydroxyeicosatetraenoic acid regulate hypoxic angiogenesis and survival of pulmonary artery endothelial cells via PI3K/Akt pathway. Am J Physiol Lung Cell Mol Physiol 2017; 314:L606-L616. [PMID: 29074487 DOI: 10.1152/ajplung.00049.2017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Dysfunction and injury of endothelial cells play critical roles in pulmonary arterial hypertension, including aberrant proliferation, suppressed apoptosis, and excessive angiogenesis. The 12-lipoxygenase and 12-hydroxyeicosatetraenoic acid pathway, which has been considered as a crucial mediator, elevates pulmonary vascular resistance and pulmonary arterial pressure. However, the mechanisms underlying the bioactivity of 12-hydroxyeicosatetraenoic acid in pulmonary vasculature, especially in endothelial cells, are still elusive. Thus we aim to determine the key role of 12-lipoxygenase/12-hydroxyeicosatetraenoic acid in angiogenesis and survival of pulmonary artery endothelial cells and ascertain the signaling pathways participating in the pathological process. Here we establish that hypoxia increases the formation of endogenous 12-hydroxyeicosatetraenoic acid through stimulation of 12-lipoxygenase. Furthermore, we put forward new information that 12-hydroxyeicosatetraenoic acid promotes endothelial cell migration and tube formation, whereas it inhibits the serum deprivation-induced apoptotic responses under hypoxia. Particularly, the regulatory effects of 12-lipoxygenase/12-hydroxyeicosatetraenoic acid on pulmonary artery endothelial cells, at least in part, depend on phosphatidylinositol 3-kinase (PI3K)/Akt signaling activation. Taken together, these results may have significant implications for understanding of pulmonary hypertension and offer a potential therapeutic concept focusing on the 12-lipoxygenase/12-hydroxyeicosatetraenoic acid signaling system.
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Affiliation(s)
- Chen Zhang
- Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University , Harbin , China
| | - Cui Ma
- Central Laboratory, College of Medical Laboratory Science and Technology, Harbin Medical University, Daqing, China
| | - Hongmin Yao
- Petit Science Center, Department of Biology, College of Arts and Sciences, Georgia State University , Atlanta, Georgia
| | - Lixin Zhang
- Central Laboratory, College of Medical Laboratory Science and Technology, Harbin Medical University, Daqing, China
| | - Xiufeng Yu
- Central Laboratory, College of Medical Laboratory Science and Technology, Harbin Medical University, Daqing, China
| | - Yumei Liu
- Central Laboratory, College of Medical Laboratory Science and Technology, Harbin Medical University, Daqing, China
| | - Tingting Shen
- Department of Pharmacology, Dalian Medical University , Dalian , China
| | - Linlin Zhang
- Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University , Harbin , China
| | - Fengying Zhang
- Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University , Harbin , China
| | - Xinxin Chen
- Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University , Harbin , China
| | - Daling Zhu
- Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University , Harbin , China.,Central Laboratory, College of Medical Laboratory Science and Technology, Harbin Medical University, Daqing, China.,Biopharmaceutical Key Laboratory of Heilongjiang Province, Harbin Medical University , Harbin , China
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Targeting of 12/15-Lipoxygenase in retinal endothelial cells, but not in monocytes/macrophages, attenuates high glucose-induced retinal leukostasis. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:636-645. [PMID: 28351645 DOI: 10.1016/j.bbalip.2017.03.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 02/27/2017] [Accepted: 03/24/2017] [Indexed: 11/22/2022]
Abstract
AIMS Our previous studies have established a role for 12/15-lipoxygenase (LO) in mediating the inflammatory response in diabetic retinopathy (DR). However, the extent at which the local or systemic induction of 12/15-LO activity involved is unclear. Thus, the current study aimed to characterize the relative contribution of retinal endothelial versus monocytic/macrophagic 12/15-LO to inflammatory responses in DR. MATERIALS & METHODS We first generated a clustered heat map for circulating bioactive lipid metabolites in the plasma of streptozotocin (STZ)-induced diabetic mice using liquid chromatography coupled with mass-spectrometry (LC-MS) to evaluate changes in circulating 12/15-LO activity. This was followed by comparing the in vitro mouse endothelium-leukocytes interaction between leukocytes isolated from 12/15-LO knockout (KO) versus those isolated from wild type (WT) mice using the myeloperoxidase (MPO) assay. Finally, we examined the effects of knocking down or inhibiting endothelial 12/15-LO on diabetes-induced endothelial cell activation and ICAM-1 expression. RESULTS Analysis of plasma bioactive lipids' heat map revealed that the activity of circulating 12/15-LO was not altered by diabetes as evident by no significant changes in the plasma levels of major metabolites derived from 12/15-lipoxygenation of different PUFAs, including linoleic acid (13-HODE), arachidonic acid (12- and 15- HETEs), eicosapentaenoic acid (12- and 15- HEPEs), or docosahexaenoic acid (17-HDoHE). Moreover, leukocytes from 12/15-LO KO mice displayed a similar increase in adhesion to high glucose (HG)-activated endothelial cells as do leukocytes from WT mice. Furthermore, abundant proteins of 12-LO and 15-LO were detected in human retinal endothelial cells (HRECs), while it was undetected (15-LO) or hardly detectable (12-LO) in human monocyte-like U937 cells. Inhibition or knock down of endothelial 12/15-LO in HRECs blocked HG-induced expression of ICAM-1, a well-known identified important molecule for leukocyte adhesion in DR. CONCLUSION Our data support that endothelial, rather than monocytic/macrophagic, 12/15-LO has a critical role in hyperglycemia-induced ICAM-1 expression, leukocyte adhesion, and subsequent local retinal barrier dysfunction. This may facilitate the development of more precisely targeted treatment strategies for DR.
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Siangjong L, Goldman DH, Kriska T, Gauthier KM, Smyth EM, Puli N, Kumar G, Falck JR, Campbell WB. Vascular hepoxilin and trioxilins mediate vasorelaxation through TP receptor inhibition in mouse arteries. Acta Physiol (Oxf) 2017; 219:188-201. [PMID: 26666460 DOI: 10.1111/apha.12642] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 11/04/2015] [Accepted: 12/08/2015] [Indexed: 01/12/2023]
Abstract
AIM 12/15-lipoxygenase (12/15-LO) metabolizes arachidonic acid (AA) into several vasoactive eicosanoids. In mouse arteries, we previously characterized the enzyme's 15-LO metabolites 12(S)-hydroxyeicosatetraenoic acid (HETE), 15-HETE, hydroxyepoxyeicosatrienoic acids (HEETAs) and 11,12,15-trihydroxyeicosatrienoic acids (11,12,15-THETAs) as endothelium-derived relaxing factors. However, the observed 12-LO metabolites remained uncharacterized. The purpose of this study was to determine the structure and biological functions of eicosanoids generated by the enzyme's 12-LO activity. METHODS Metabolites extracted from aortas of C57BL/6 male mice were separated using a series of reverse and normal phase chromatographic steps and identified as hepoxilin A3 , trioxilin A3 and trioxilin C3 by mass spectrometry. Activities of these natural compounds were tested on isometric tension and intracellular calcium release. The role of thromboxane (TP) receptor was determined in HEK293 cells overexpressing TPα receptor (TPα -HEK). RESULTS All identified vascular 12-LO metabolites were biologically active. In mouse mesenteric arteries, trioxilin A3 , C3 and hepoxilin A3 (3 μm) relaxed arteries constricted with the thromboxane mimetic, U46619-constricted arteries (maximum relaxations of 78.9 ± 3.2, 29.7 ± 4.6, 82.2 ± 5.0 and 88.0 ± 2.4% respectively), but not phenylephrine-constricted arteries. In TPα-HEK cells, trioxilin A3 , C3 and hepoxilin A3 (10 μm) inhibited U46619 (10 nM)-induced increases in intracellular calcium by 53.0 ± 7.2%, 32.8 ± 5.0% and 37.9 ± 13.5% respectively. In contrast, trioxilin B3 and hepoxilin B3 were not synthesized in arteries and exhibited little biological activity. CONCLUSION Trioxilin A3 and C3 and hepoxilin A3 are endogenous vascular relaxing factors. They are not endothelium-derived hyperpolarizing factors but mediate vascular relaxation by inhibiting TP agonist-induced increases in intracellular calcium. Thus, they regulate vascular homeostasis by acting as endogenous TP antagonists.
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Affiliation(s)
- L. Siangjong
- Department of Pharmacology and Toxicology; Medical College of Wisconsin; Milwaukee WI USA
- Faculty of Pharmacy; Silpakorn University; Nakorn Pathom Thailand
| | - D. H. Goldman
- Department of Pharmacology and Toxicology; Medical College of Wisconsin; Milwaukee WI USA
| | - T. Kriska
- Department of Pharmacology and Toxicology; Medical College of Wisconsin; Milwaukee WI USA
| | - K. M. Gauthier
- Department of Pharmacology and Toxicology; Medical College of Wisconsin; Milwaukee WI USA
| | - E. M. Smyth
- Department of Pharmacology; University of Pennsylvania; Philadelphia PA USA
| | - N. Puli
- Department of Biochemistry; University of Texas Southwestern Medical Center; Dallas TX USA
| | - G. Kumar
- Department of Biochemistry; University of Texas Southwestern Medical Center; Dallas TX USA
| | - J. R. Falck
- Department of Biochemistry; University of Texas Southwestern Medical Center; Dallas TX USA
| | - W. B. Campbell
- Department of Pharmacology and Toxicology; Medical College of Wisconsin; Milwaukee WI USA
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Imai Y, Dobrian AD, Weaver JR, Butcher MJ, Cole BK, Galkina EV, Morris MA, Taylor-Fishwick DA, Nadler JL. Interaction between cytokines and inflammatory cells in islet dysfunction, insulin resistance and vascular disease. Diabetes Obes Metab 2013; 15 Suppl 3:117-29. [PMID: 24003928 PMCID: PMC3777698 DOI: 10.1111/dom.12161] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 05/12/2013] [Indexed: 12/17/2022]
Abstract
Inflammation is an established pathogenic player in insulin resistance, islet demise and atherosclerosis. The complex interactions between cytokines, immune cells and affected tissues result in sustained inflammation in diabetes and atherosclerosis. 12- and 15-lipoxygenase (LO), such as 12/15-LO, produces a variety of metabolites through peroxidation of fatty acids and potentially contributes to the complex molecular crosstalk at the site of inflammation. 12- and 15-LO pathways are frequently activated in tissues affected by diabetes and atherosclerosis including adipose tissue (AT), islets and the vasculature. Moreover, mice with whole body and tissue-specific knockout of 12/15-LO are protected against insulin resistance, hyperglycaemia and atherosclerosis supporting functional contribution of 12- and 15-LO pathways in diabetes and atherosclerosis. Recently, it has emerged that there is a temporal regulation of the particular isoforms of 12- and 15-LO in human AT and islets during the development of type 1 and type 2 diabetes and obesity. Analyses of tissues affected by diabetes and atherosclerosis also implied the roles of interleukin (IL)-12 and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-1 (NOX-1) in islets and IL-17A in atherosclerosis. Future studies should aim to test the efficacy of inhibitions of these mediators for treatment of diabetes and atherosclerosis.
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Affiliation(s)
- Y Imai
- Department of Internal Medicine, Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, VA 23507, USA.
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Cole BK, Lieb DC, Dobrian AD, Nadler JL. 12- and 15-lipoxygenases in adipose tissue inflammation. Prostaglandins Other Lipid Mediat 2013; 104-105:84-92. [PMID: 22951339 PMCID: PMC3526691 DOI: 10.1016/j.prostaglandins.2012.07.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 07/18/2012] [Accepted: 07/30/2012] [Indexed: 02/06/2023]
Abstract
The lipoxygenases (LOs) are principal enzymes involved in the oxidative metabolism of polyunsaturated fatty acids, including arachidonic acid. 12- and 15-LO and their lipid metabolites have been implicated in the development of insulin resistance and diabetes. Adipose tissue, and in particular visceral adipose tissue, plays a primary role in the development of the inflammation seen in these conditions. 12- and 15-LO and their lipid metabolites act as upstream regulators of many of the cytokines involved in the inflammatory response in adipose tissue. While the role that 12- and 15-LO play in chronically inflamed adipose tissue is becoming clearer, there are still many questions that remain unanswered regarding their activation, signaling pathways, and roles in healthy fat. 12- and 15-LO also generate products with anti-inflammatory properties that are under investigation. Therefore, 12- and 15-LO have the potential to be very important targets for therapeutics aimed at reducing insulin resistance and the comorbid conditions associated with obesity.
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Affiliation(s)
- Banumathi K. Cole
- Department of Internal Medicine, Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, VA
| | - David C. Lieb
- Department of Internal Medicine, Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, VA
| | - Anca D. Dobrian
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA
| | - Jerry L. Nadler
- Department of Internal Medicine, Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, VA
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Kundumani-Sridharan V, Dyukova E, Hansen DE, Rao GN. 12/15-Lipoxygenase mediates high-fat diet-induced endothelial tight junction disruption and monocyte transmigration: a new role for 15(S)-hydroxyeicosatetraenoic acid in endothelial cell dysfunction. J Biol Chem 2013; 288:15830-42. [PMID: 23589307 DOI: 10.1074/jbc.m113.453290] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
A convincing body of evidence suggests that 12/15-lipoxygenase (12/15-LO) plays a role in atherosclerosis. However, the mechanisms of its involvement in the pathogenesis of this disease are not clear. Therefore, the purpose of this study is to understand the mechanisms by which 12/15-LO mediates endothelial dysfunction. 15(S)-Hydroxyeicosatetraenoic acid (15(S)-HETE), the major 12/15-LO metabolite of arachidonic acid (AA), induced endothelial barrier permeability via Src and Pyk2-dependent zonula occluden (ZO)-2 tyrosine phosphorylation and its dissociation from the tight junction complexes. 15(S)-HETE also stimulated macrophage adhesion to the endothelial monolayer in Src and Pyk2-dependent manner. Ex vivo studies revealed that exposure of arteries from WT mice to AA or 15(S)-HETE led to Src-Pyk2-dependent ZO-2 tyrosine phosphorylation, tight junction disruption, and macrophage adhesion, whereas the arteries from 12/15-LO knock-out mice are protected from these effects of AA. Feeding WT mice with a high-fat diet induced the expression of 12/15-LO in the arteries leading to tight junction disruption and macrophage adhesion and deletion of the 12/15-LO gene disallowed these effects. Thus, the findings of this study provide the first evidence of the role of 12/15-LO and its AA metabolite, 15(S)-HETE, in high-fat diet-induced endothelial tight junction disruption and macrophage adhesion, the crucial events underlying the pathogenesis of atherosclerosis.
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Kim HY, Jeong DW, Park HS, Lee TY, Kim HS. Comparison of 12-lipoxygenase expression in vascular smooth muscle cells from old normotensive Wistar-Kyoto rats with spontaneously hypertensive rats. Hypertens Res 2012; 36:65-73. [PMID: 22875070 DOI: 10.1038/hr.2012.119] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Vascular aging and essential hypertension cause similar structural and molecular modifications in the vasculature. The 12-lipoxygenase (LO) pathway of arachidonic acid metabolism is linked to cell growth and the pathology of hypertension. Thus, elevated expression of 12-LO has been observed in vascular smooth muscle cells (VSMCs) from spontaneously hypertensive rats (SHR). In the present study, we investigated the differences in 12-LO expression and activity between VSMCs from old normotensive Wistar-Kyoto rats (old WKY, 90-week old) and SHR (13-week old). The protein and mRNA expression of basal or angiotensin II (Ang II)-induced 12-LO in old WKY VSMCs were higher than those in SHR VSMCs. The degradation rate of 12-LO mRNA in old WKY VSMCs was slower than that in SHR VSMCs. However, basal or Ang II-induced 12-LO mRNAs in both old WKY and SHR VSMCs decayed more rapidly than that in young WKY (13-week old) VSMCs. Higher expression of 12-LO in old WKY VSMCs than in SHR VSMCs was correlated with the expression level of Ang II subtype 1 receptor (AT(1)R). The reduced levels of nitric oxide (NO) in old WKY and SHR VSMCs compared with young WKY VSMCs were similar, and there was no significant difference in NO production between old WKY and SHR VSMCs transfected with 12-LO siRNA. In addition, in contrast to the proliferation of SHR VSMCs, the proliferation of old WKY VSMCs was not dependent on 12-LO activation. These results suggest that the potential role of 12-LO in normotensive aging vasculature may be different from that in SHR vasculature.
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Affiliation(s)
- Hye Young Kim
- Department of Microbiology, College of Medicine, Yeungnam University, Daegu, South Korea
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13
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Angiotensin II inhibits chemokine CCL5 expression in vascular smooth muscle cells from spontaneously hypertensive rats. Hypertens Res 2011; 34:1313-20. [DOI: 10.1038/hr.2011.132] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Hutchinson JL, Rajagopal SP, Sales KJ, Jabbour HN. Molecular regulators of resolution of inflammation: potential therapeutic targets in the reproductive system. Reproduction 2011; 142:15-28. [DOI: 10.1530/rep-11-0069] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Inflammatory processes are central to reproductive events including ovulation, menstruation, implantation and labour, while inflammatory dysregulation is a feature of numerous reproductive pathologies. In recent years, there has been much research into the endogenous mechanisms by which inflammatory reactions are terminated and tissue homoeostasis is restored, a process termed resolution. The identification and characterisation of naturally occurring pro-resolution mediators including lipoxins and annexin A1 has prompted a shift in the field of anti-inflammation whereby resolution is now observed as an active process, triggered as part of a normal inflammatory response. This review will address the process of resolution, discuss available evidence for expression of pro-resolution factors in the reproductive tract and explore possible roles for resolution in physiological reproductive processes and associated pathologies.
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Félétou M. The Endothelium, Part I: Multiple Functions of the Endothelial Cells -- Focus on Endothelium-Derived Vasoactive Mediators. ACTA ACUST UNITED AC 2011. [DOI: 10.4199/c00031ed1v01y201105isp019] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Pergola C, Jazzar B, Rossi A, Buehring U, Luderer S, Dehm F, Northoff H, Sautebin L, Werz O. Cinnamyl-3,4-dihydroxy-α-cyanocinnamate is a potent inhibitor of 5-lipoxygenase. J Pharmacol Exp Ther 2011; 338:205-13. [PMID: 21447614 DOI: 10.1124/jpet.111.180794] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Lipoxygenases (LOs) are iron-containing enzymes that catalyze the conversion of arachidonic acid into hydroperoxyeicosatetraenoic acids (HPETEs) and other bioactive lipid mediators. In mammals, 5-LO, 15-LO, and 12-LO enzymes seem to have distinct roles in pathophysiological contexts, which have emphasized the need for selective inhibitors. Cinnamyl-3,4-dihydroxy-α-cyanocinnamate (CDC) has been proposed as potent and selective inhibitor of platelet-type 12-LO (p12-LO). Here, we re-evaluated the selectivity profile of CDC on LOs, and we show that CDC is a potent and direct inhibitor of 5-LO. CDC reduced 5-LO activity in cell-free assays (purified human recombinant enzyme or leukocyte homogenates), with IC(50) values in the low nanomolar range (9-25 nM) and a selectivity index of approximately 35 and 15 over p12-LO and 15-LO1, respectively. Likewise, CDC inhibited 5-LO product formation in intact human polymorphonuclear leukocytes and monocytes (IC(50) = 0.45-0.8 μM). A lower potency was observed for 15-LO1, whereas p12-LO activity in platelets was hardly affected. In human whole blood, CDC efficiently reduced the formation of 5-LO products, and similar effects were observed for 12(S)-H(P)ETE and 15(S)-H(P)ETE. Finally, CDC (3.5 and 7 mg/kg i.p.) was effective in vivo in the platelet-activating factor-induced shock in mice and reduced formation of the 5-LO product leukotriene B(4) in the rat carrageenan-induced pleurisy after a single oral dose of 10 mg/kg. Together, our data demonstrate that CDC is a potent inhibitor of 5-LO with efficacy in vivo and encourage further development of CDC as the lead compound.
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Affiliation(s)
- Carlo Pergola
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, University of Jena, Jena, Germany.
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18
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Al-Shabrawey M, Mussell R, Kahook K, Tawfik A, Eladl M, Sarthy V, Nussbaum J, El-Marakby A, Park SY, Gurel Z, Sheibani N, Maddipati KR. Increased expression and activity of 12-lipoxygenase in oxygen-induced ischemic retinopathy and proliferative diabetic retinopathy: implications in retinal neovascularization. Diabetes 2011; 60:614-24. [PMID: 21228311 PMCID: PMC3028363 DOI: 10.2337/db10-0008] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Arachidonic acid is metabolized by 12-lipoxygenase (12-LOX) to 12-hydroxyeicosatetraenoic acid (12-HETE) and has an important role in the regulation of angiogenesis and endothelial cell proliferation and migration. The goal of this study was to investigate whether 12-LOX plays a role in retinal neovascularization (NV). RESEARCH DESIGN AND METHODS Experiments were performed using retinas from a murine model of oxygen-induced ischemic retinopathy (OIR) that was treated with and without the LOX pathway inhibitor, baicalein, or lacking 12-LOX. We also analyzed vitreous samples from patients with and without proliferative diabetic retinopathy (PDR). Western blotting and RT-PCR were used to assess the expression of 12-LOX, vascular endothelial growth factor (VEGF), and pigment epithelium-derived factor (PEDF). Liquid chromatography-mass spectrometry was used to assess the amounts of HETEs in the murine retina and human vitreous samples. The effects of 12-HETE on VEGF and PEDF expression were evaluated in Müller cells (rMCs), primary mouse retinal pigment epithelial cells, and astrocytes. RESULTS Retinal NV during OIR was associated with increased 12-LOX expression and 12-, 15-, and 5-HETE production. The amounts of HETEs also were significantly higher in the vitreous of diabetic patients with PDR. Retinal NV was markedly abrogated in mice treated with baicalein or mice lacking 12-LOX. This was associated with decreased VEGF expression and restoration of PEDF levels. PEDF expression was reduced in 12-HETE-treated rMCs, astrocytes, and the retinal pigment epithelium. Only rMCs and astrocytes showed increased VEGF expression by 12-HETE. CONCLUSIONS 12-LOX and its product HETE are important regulators of retinal NV through modulation of VEGF and PEDF expression and could provide a new therapeutic target to prevent and treat ischemic retinopathy.
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Affiliation(s)
- Mohamed Al-Shabrawey
- Department of Oral Biology and Anatomy, Medical College of Georgia, Augusta, Georgia, USA.
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Pozzi A, Zent R. Regulation of endothelial cell functions by basement membrane- and arachidonic acid-derived products. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2011; 1:254-272. [PMID: 20835995 DOI: 10.1002/wsbm.7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Angiogenesis, the formation of new blood vessels from preexisting vasculature, is required for normal physiological as well as pathological events. The angiogenic process requires endothelial cells to proliferate, migrate, and undergo tubulogenesis. These multistep processes necessitate secretion of pro-angiogenic growth factors, activation of specific intracellular signaling, and interaction of endothelial cells with basement membrane (BM) extracellular matrix components. The generation and release of angiogenic molecules are highly regulated and are influenced by numerous factors, including BM-derived fragments, proteolytic enzymes, as well as metabolites of arachidonic acid (AA). The interactions between these key modulators of angiogenesis is extremely complex, as AA metabolites can regulate the synthesis of soluble angiogenic factors, BM components, as well as enzymes capable of cleaving BM components, which result in the generation of pro- and/or anti-angiogenic products. Furthermore, some BM-derived fragments can alter the expression of AA-converting enzymes and consequently the synthesis of angiogenic factors. In this review we describe the relationship between BM components and AA metabolites with respect to the regulation of endothelial cell functions in health and disease.
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Affiliation(s)
- Ambra Pozzi
- Departments of Medicine, Cancer Biology and Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Roy Zent
- Department of Medicine, Veterans Affairs Hospital, Nashville, TN 37232, USA
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20
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Kim HY, Choi JH, Kang YJ, Park SY, Choi HC, Kim HS. Reparixin, an Inhibitor of CXCR1 and CXCR2 Receptor Activation, Attenuates Blood Pressure and Hypertension-Related Mediators Expression in Spontaneously Hypertensive Rats. Biol Pharm Bull 2011; 34:120-7. [DOI: 10.1248/bpb.34.120] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Hye Young Kim
- Department of Microbiology, Aging-associated Vascular Disease Research Center, College of Medicine, Yeungnam University
| | - Jin Hee Choi
- Department of Microbiology, Aging-associated Vascular Disease Research Center, College of Medicine, Yeungnam University
| | - Young Jin Kang
- Department of Pharmacology, Aging-associated Vascular Disease Research Center, College of Medicine, Yeungnam University
| | - So Young Park
- Department of Physiology, Aging-associated Vascular Disease Research Center, College of Medicine, Yeungnam University
| | - Hyoung Chul Choi
- Department of Pharmacology, Aging-associated Vascular Disease Research Center, College of Medicine, Yeungnam University
| | - Hee Sun Kim
- Department of Microbiology, Aging-associated Vascular Disease Research Center, College of Medicine, Yeungnam University
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21
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Martínez-Clemente M, Ferré N, Titos E, Horrillo R, González-Périz A, Morán-Salvador E, López-Vicario C, Miquel R, Arroyo V, Funk CD, Clària J. Disruption of the 12/15-lipoxygenase gene (Alox15) protects hyperlipidemic mice from nonalcoholic fatty liver disease. Hepatology 2010; 52:1980-91. [PMID: 20967760 DOI: 10.1002/hep.23928] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Accepted: 08/10/2010] [Indexed: 12/19/2022]
Abstract
UNLABELLED We have shown that Alox15, the gene encoding for 12/15-lipoxygenase (12/15-LO), is markedly up-regulated in livers from apolipoprotein E-deficient (ApoE(-/-)) mice, which spontaneously develop nonalcoholic fatty liver disease secondary to hyperlipidemia. In the current study, we used ApoE(-/-) mice with a targeted disruption of the Alox15 gene to assess the role of 12/15-LO in the development and progression of hepatic steatosis and inflammation. Compared with ApoE(-/-) mice, which exhibited extensive hepatic lipid accumulation and exacerbated inflammatory injury, ApoE/12/15-LO double-knockout (ApoE(-/-)/12/15-LO(-/-)) mice showed reduced serum alanine aminotransferase levels; decreased hepatic steatosis, inflammation, and macrophage infiltration; and decreased fatty acid synthase, tumor necrosis factor α (TNFα), monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-18, and IL-6 expression. Remarkably, disruption of Alox15 attenuated glucose intolerance and high-fat diet-induced insulin resistance, up-regulated insulin receptor substrate-2, and exerted opposite effects on hepatic c-Jun amino-terminal kinase and adenosine monophosphate-activated protein kinase phosphorylation, known negative and positive regulators of insulin signaling, respectively. In adipose tissue, the absence of Alox15 induced significant reductions in the expression of the proinflammatory and insulin-resistant adipokines MCP-1, TNFα, and resistin while increasing the expression of glucose transporter-4. Interestingly, compared with ApoE(-/-) mice, which exhibited increased hepatic caspase-3 staining, ApoE(-/-)/12/15-LO(-/-) mice showed attenuated hepatocellular injury. Consistent with this finding, hepatocytes isolated from ApoE(-/-) mice were more vulnerable to TNFα-induced programmed cell death, an effect that was not observed in hepatocytes carrying a targeted disruption of the Alox15 gene. CONCLUSION Collectively, our data suggest a potentially relevant mechanism linking 12/15-LO to the promotion of hepatic steatosis, insulin resistance, and inflammation in experimental liver disease of metabolic origin.
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Affiliation(s)
- Marcos Martínez-Clemente
- Department of Biochemistry and Molecular Genetics, Hospital Clínic, Centro de Investigaciones Biomédicas Esther Koplowitz, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Spain
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22
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Dobrian AD, Lieb DC, Ma Q, Lindsay JW, Cole BK, Ma K, Chakrabarti SK, Kuhn NS, Wohlgemuth SD, Fontana M, Nadler JL. Differential expression and localization of 12/15 lipoxygenases in adipose tissue in human obese subjects. Biochem Biophys Res Commun 2010; 403:485-90. [PMID: 21094135 DOI: 10.1016/j.bbrc.2010.11.065] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Accepted: 11/15/2010] [Indexed: 01/04/2023]
Abstract
Adipose tissue inflammation in obesity is a major factor leading to cardiovascular disease and type 2 diabetes.12/15 lipoxygenases (ALOX) play an important role in the generation of inflammatory mediators, insulin resistance and downstream immune activation in animal models of obesity. However, the expression and roles of 12/15ALOX isoforms, and their cellular sources in human subcutaneous (sc) and omental (om) fat in obesity is unknown. The objective of this study was to examine the gene expression and localization of ALOX isoforms and relevant downstream cytokines in subcutaneous (sc) and omental (om) adipose tissue in obese humans. Paired biopsies of sc and om fat were obtained during bariatric surgeries from 24 morbidly obese patients. Gene and protein expression for ALOX15a, ALOX15b and ALOX 12 were measured by real-time PCR and western blotting in adipocytes and stromal vascular fractions (SVF) from om and sc adipose tissue along with the mRNA expression of the downstream cytokines IL-12a, IL-12b, IL-6, IFNγ and the chemokine CXCL10. In a paired analysis, all ALOX isoforms, IL-6, IL-12a and CXCL10 were significantly higher in om vs. sc fat. ALOX15a mRNA and protein expression was found exclusively in om fat. All of the ALOX isoforms were expressed solely in the SVF. Further fractionation of the SVF in CD34+ and CD34- cells indicated that ALOX15a is predominantly expressed in the CD34+ fraction including vascular and progenitor cells, while ALOX15B is mostly expressed in the CD34- cells containing various leucocytes and myeloid cells. This result was confirmed by immunohistochemistry showing exclusive localization of ALOX15a in the om fat and predominantly in the vasculature and non-adipocyte cells. Our finding is identifying selective expression of ALOX15a in human om but not sc fat. This is a study showing a major inflammatory gene exclusively expressed in visceral fat in humans.
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Affiliation(s)
- Anca D Dobrian
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA 23507, USA.
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23
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Dobrian AD, Lieb DC, Cole BK, Taylor-Fishwick DA, Chakrabarti SK, Nadler JL. Functional and pathological roles of the 12- and 15-lipoxygenases. Prog Lipid Res 2010; 50:115-31. [PMID: 20970452 DOI: 10.1016/j.plipres.2010.10.005] [Citation(s) in RCA: 231] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 10/13/2010] [Accepted: 10/14/2010] [Indexed: 12/25/2022]
Abstract
The 12/15-lipoxygenase enzymes react with fatty acids producing active lipid metabolites that are involved in a number of significant disease states. The latter include type 1 and type 2 diabetes (and associated complications), cardiovascular disease, hypertension, renal disease, and the neurological conditions Alzheimer's disease and Parkinson's disease. A number of elegant studies over the last thirty years have contributed to unraveling the role that lipoxygenases play in chronic inflammation. The development of animal models with targeted gene deletions has led to a better understanding of the role that lipoxygenases play in various conditions. Selective inhibitors of the different lipoxygenase isoforms are an active area of investigation, and will be both an important research tool and a promising therapeutic target for treating a wide spectrum of human diseases.
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Affiliation(s)
- Anca D Dobrian
- Eastern Virginia Medical School, Department of Physiological Sciences, Lewis Hall, Room 2027, 700 W. Olney Road, Norfolk, VA 23507, United States.
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24
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Buczynski MW, Svensson CI, Dumlao DS, Fitzsimmons BL, Shim JH, Scherbart TJ, Jacobsen FE, Hua XY, Yaksh TL, Dennis EA. Inflammatory hyperalgesia induces essential bioactive lipid production in the spinal cord. J Neurochem 2010; 114:981-93. [PMID: 20492349 DOI: 10.1111/j.1471-4159.2010.06815.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Lipid molecules play an important role in regulating the sensitivity of sensory neurons and enhancing pain perception, and growing evidence indicates that the effect occurs both at the site of injury and in the spinal cord. Using high-throughput mass spectrometry methodology, we sought to determine the contribution of spinal bioactive lipid species to inflammation-induced hyperalgesia in rats. Quantitative analysis of CSF and spinal cord tissue for eicosanoids, ethanolamides and fatty acids revealed the presence of 102 distinct lipid species. After induction of peripheral inflammation by intra-plantar injection of carrageenan to the ipsilateral hind paw, lipid changes in cyclooxygenase (COX) and 12-lipoxygenase (12-LOX) signaling pathways peaked at 4 h in the CSF. In contrast, changes occurred in a temporally disparate manner in the spinal cord with LOX-derived hepoxilins followed by COX-derived prostaglandin E(2), and subsequently the ethanolamine anandamide. Systemic treatment with the mu opioid agonist morphine, the COX inhibitor ketorolac, or the LOX inhibitor nordihydroguaiaretic acid significantly reduced tactile allodynia, while their effects on the lipid metabolites were different. Morphine did not alter the lipid profile in the presence or absence of carrageenan inflammation. Ketorolac caused a global reduction in eicosanoid metabolism in naïve animals that remained suppressed following injection of carrageenan. Nordihydroguaiaretic acid-treated animals also displayed reduced basal levels of COX and 12-LOX metabolites, but only 12-LOX metabolites remained decreased after carrageenan treatment. These findings suggest that both COX and 12-LOX play an important role in the induction of carrageenan-mediated hyperalgesia through these pathways.
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Affiliation(s)
- Matthew W Buczynski
- Department of Pharmacology, Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
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25
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Hanif K, Bid HK, Konwar R. Reinventing the ACE inhibitors: some old and new implications of ACE inhibition. Hypertens Res 2009; 33:11-21. [PMID: 19911001 DOI: 10.1038/hr.2009.184] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Since their inception, angiotensin-converting enzyme (ACE) inhibitors have been used as first-line therapy for the treatment of cardiovascular and renal diseases. They restore the balance between the vasoconstrictive salt-retentive and hypertrophy-causing peptide angiotensin II (Ang II) and bradykinin, a vasodilatory and natriuretic peptide. As ACE is a promiscuous enzyme, ACE inhibitors alter the metabolism of a number of other vasoactive substances. ACE inhibitors decrease systemic vascular resistance without increasing heart rate and promote natriuresis. They have been proven effective in the treatment of hypertension, and reduce mortality in congestive heart failure and left ventricular dysfunction after myocardial infarction. They inhibit ischemic events and stabilize plaques. Furthermore, they delay the progression of diabetic nephropathy and neuropathy and act as antioxidants. Ongoing studies have elucidated protective roles for them in both memory-related disorders and cancer. Lastly, N- and C-domain selective ACE inhibitors have led to new uses for ACE inhibitors.
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Affiliation(s)
- Kashif Hanif
- Division of Pharmacology, Central Drug Research Institute (CSIR), Lucknow, Uttar Pradesh, India.
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26
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Kim JH, Kim HS. Downregulation of Angiotensin II-Induced 12-Lipoxygenase Expression and Cell Proliferation in Vascular Smooth Muscle Cells from Spontaneously Hypertensive Rats by CCL5. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2009; 13:385-92. [PMID: 19915702 DOI: 10.4196/kjpp.2009.13.5.385] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Revised: 10/21/2009] [Accepted: 10/23/2009] [Indexed: 11/15/2022]
Abstract
Angiotensin II (Ang II) plays an important role in vascular hypertension. The role of the chemokine CCL5 on Ang II-induced activities in vascular smooth muscle cells (VSMCs) has not been studied. In this study, we elucidated the effect of CCL5 on Ang II-induced 12-lipoxygenase (LO) expression and cell proliferation in spontaneously hypertensive rats (SHR) VSMCs. CCL5 decreased Ang II-induced 12-LO mRNA expression and protein production, and it increased Ang II type 2 (AT(2)) receptor expression in SHR VSMCs. The inhibitory effect of CCL5 on Ang II-induced 12-LO mRNA expression was mediated through the AT(2) receptor. Although treatment of CCL5 alone induced SHR VSMCs proliferation, CCL5 inhibited Ang II-induced VSMCs proliferation and PD123,319, an AT(2) receptor antagonist, blocked the inhibitory effect of CCL5 on Ang II-induced VSMCs proliferation. Phosphorylation of p38 was detected in VSMCs treated with Ang II or CCL5 alone. But, decrease of p38 phosphorylation was detected in VSMCs treated with Ang II and CCL5 simultaneously (Ang II/CCL5) and PD123,319 increased p38 phosphorylation in VSMCs treated with Ang II/CCL5. Therefore, these results suggest that the inhibitory effect of CCL5 on Ang II-induced VSMCs proliferation is mediated by the AT(2) receptor via p38 inactivation, and CCL5 may play a beneficial role in Ang II-induced vascular hypertension.
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Affiliation(s)
- Jung Hae Kim
- Department of Microbiology, and Aging-associated Vascular Disease Research Center, College of Medicine, Yeungnam University, Daegu 705-717, Korea
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27
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Kim JH, Kang YJ, Kim HS. IL-8/CXCL8 Upregulates 12-Lipoxygenase Expression in Vascular Smooth Muscle Cells from Spontaneously Hypertensive Rats. Immune Netw 2009; 9:106-13. [PMID: 20107540 PMCID: PMC2803299 DOI: 10.4110/in.2009.9.3.106] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Revised: 05/15/2009] [Accepted: 05/26/2009] [Indexed: 12/24/2022] Open
Abstract
Background We previously demonstrated remarkable differences in the expression of IL-8/CXCL8 in aortic tissues and vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) compared to VSMC from normotensive Wistar-Kyoto rats (WKY). In the present study, we investigated the direct effect of IL-8/CXCL8 on expression of 12-lipoxygenase (LO), a hypertensive modulator, in SHR VSMC. Methods Cultured aortic VSMC from SHR and WKY were used. Expression of 12-LO mRNA was determined by real-time polymerase chain reaction. Phosphorlyation of ERK1/2 and production of 12-LO and angiotensin II subtype 1 (AT1) receptor were assessed by Western blots. IL-8/CXCL8-stimulated DNA synthesis was determined by measuring incorporation of [3H]-thymidine. And effect of IL-8/CXCL8 on vascular tone was determined by phenylephrine-induced contraction of thoracic aortic rings. Results Treatment with IL-8/CXCL8 greatly increased 12-LO mRNA expression and protein production compared to treatment with angiotensin II. IL-8/CXCL8 also increased the expression of the AT1 receptor. The increase in 12-LO induced by IL-8/CXCL8 was inhibited by treatment with an AT1 receptor antagonist. The induction of 12-LO mRNA production and the proliferation of SHR VSMC by IL-8/CXCL8 was mediated by the ERK pathway. The proliferation of SHR VSMC and the vascular contraction in the thoracic aortic ring, both of which were induced by IL-8/CXCL8, were inhibited by baicalein, a 12-LO inhibitor. Conclusion These results suggest that the potential role of IL-8/CXCL8 in hypertensive processes is likely mediated through the 12-LO pathway.
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Affiliation(s)
- Jung Hae Kim
- Department of Microbiology, College of Medicine, Yeungnam University, Daegu, Korea
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Abstract
Eicosanoids and the enzymes responsible for their generation in living systems are involved in the mediation of multiple physiological and pathophysiological responses. These bioactive metabolites are part of complex cascades that initiate and perpetuate several disease processes such as atherosclerosis, arthritis, neurodegenerative conditions, and cancer. The intricate role played by each of these metabolites in the initiation, progression, and metastasis of solid tumors has been a subject of intense research in the scientific community. This review summarizes some of the key aspects of eicasonoids and the associated enzymes, and the pathways they mediate in promoting tumor progression and metastasis.
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Affiliation(s)
- Sriram Krishnamoorthy
- Departments of Pathology, and Chemistry, Wayne State University School of Medicine, Detroit, MI 48202, USA
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Prasad VVTS, Nithipatikom K, Harder DR. Ceramide elevates 12-hydroxyeicosatetraenoic acid levels and upregulates 12-lipoxygenase in rat primary hippocampal cell cultures containing predominantly astrocytes. Neurochem Int 2008; 53:220-9. [PMID: 18680775 DOI: 10.1016/j.neuint.2008.07.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Revised: 06/01/2008] [Accepted: 07/01/2008] [Indexed: 10/21/2022]
Abstract
We report, exogenous addition of ceramide significantly increases 12-hydroxyeicosatetraenoic acid [12-(S)-HETE] levels, in a dose-dependent manner. 12-(S)-HETE levels, in 20, 30 and 40microM ceramide exposed rat primary hippocampal cell cultures containing predominantly astrocytes and few neurons and other glial cells (the cultured hippocampal cells were predominantly astrocytes amounting to over 99% of total cells with few neurons and other glial cells) amounted to 207, 260 and 408% of the controls, respectively. However, dihydroceramide, an inactive analog of ceramide did not alter the levels of 12-(S)-HETE. Ceramide also increased the mRNA and protein expression, and activity of 12-lipoxygease (12-LOX) needed for the synthesis of 12(S)-HETE. These results indicate a possible link between ceramide and 12-LOX pathway. However, ceramide did not alter expression of 5-lipoxygenase (5-LOX), another member of the lipoxygenase family. However, ceramide upregulated expression of cytosolic phospholipase-A(2) (cPLA(2)) and cyclooxygenase-2 (COX-2). Further, ceramide caused a significant increase in the levels of reactive oxygen species (ROS). Ceramide-mediated generation of ROS was inhibited by baicalien but not by indomethacin. In addition, ceramide treated cells exhibited increased mRNA expression of DNA damage induced transcript3 (Ddit3). This report which demonstrate induction of pro-carcinogenic 12-LOX pathway by an anticancer ceramide, may be relevant to cancer biologists studying drug resistant tumors and devising potent anticancer therapeutic strategies to treat drug resistant tumors. These results indicate possibility of 12-LOX involvement in ceramide-mediated generation of ROS and cellular oxidative stress. Induction of 12-LOX pathway by ceramide may have implications in understanding pathophysiology of neurodegenerative diseases involving ROS generation and inflammation.
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30
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Endsley MP, Aggarwal N, Isbell MA, Wheelock CE, Hammock BD, Falck JR, Campbell WB, Nithipatikom K. Diverse roles of 2-arachidonoylglycerol in invasion of prostate carcinoma cells: Location, hydrolysis and 12-lipoxygenase metabolism. Int J Cancer 2007; 121:984-91. [PMID: 17443494 PMCID: PMC2565646 DOI: 10.1002/ijc.22761] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Endogenous 2-arachidonoylglycerol (2-AG) is antiinvasive in androgen-independent prostate carcinoma (PC-3) cells. Invasion of PC-3 cells is also inhibited by exogenously added noladin ether, a non-hydrolyzable analog of 2-AG. In contrast, exogenous 2-AG has the opposite effect. Cell invasion significantly increased with high concentrations of exogenous 2-AG. In PC-3 cells, arachidonic acid (AA) and 12-hydroxyeicosatetraenoic acid (12-HETE) concentrations increased along with exogenously added 2-AG, and 12-HETE concentrations increased with exogenously added AA. Invasion of PC-3 cells also increased with exogenously added AA and 12(S)-HETE but not 12(R)-HETE. The exogenous 2-AG-induced invasion of PC-3 cells was inhibited by 3-octylthio-1,1,1-trifluoropropan-2-one (OTFP, an inhibitor of 2-AG hydrolysis) and baicalein (a 12-LO inhibitor). Western blot and RT-PCR analyses indicated expression of 12-HETE producing lipoxygenases (LOs), platelet-type 12-LO (P-12-LO) and leukocyte-type 12-LO (L-12-LO), in PC-3 cells. These results suggest that exogenous 2-AG induced, rather inhibited, cell invasion because of its rapid hydrolysis to free AA, and further metabolism by 12-LO of AA to 12(S)-HETE, a promoter of PC cell invasion. The results also suggest that PC-3 cells and human prostate stromal (WPMY-1) cells released free AA, 2-AG, and 12-HETE. In the microenvironment of the PC cells, this may contribute to the cell invasion. The 2-AG hydrolysis and concentration of 2-AG in microenvironment are critical for PC cell's fate. Therefore, inhibitors of 2-AG hydrolysis could potentially serve as therapeutic agents for the treatment of prostate cancer. (c) 2007 Wiley-Liss, Inc.
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MESH Headings
- 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid/metabolism
- 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid/pharmacology
- Arachidonate 12-Lipoxygenase/metabolism
- Arachidonic Acid/pharmacology
- Arachidonic Acids/metabolism
- Arachidonic Acids/pharmacology
- Blotting, Western
- Chromatography, Liquid
- Endocannabinoids
- Glycerides/metabolism
- Glycerides/pharmacology
- Humans
- Hydrolysis
- Male
- Neoplasm Invasiveness
- Prostatic Neoplasms/enzymology
- Prostatic Neoplasms/metabolism
- Prostatic Neoplasms/pathology
- Reverse Transcriptase Polymerase Chain Reaction
- Spectrometry, Mass, Electrospray Ionization
- Stromal Cells/metabolism
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Affiliation(s)
- Michael P Endsley
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA
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Wittwer J, Hersberger M. The two faces of the 15-lipoxygenase in atherosclerosis. Prostaglandins Leukot Essent Fatty Acids 2007; 77:67-77. [PMID: 17869078 DOI: 10.1016/j.plefa.2007.08.001] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2007] [Revised: 07/12/2007] [Accepted: 08/01/2007] [Indexed: 01/02/2023]
Abstract
Chronic inflammation plays a major role in atherogenesis and understanding the role of inflammation and its resolution will offer novel approaches to interfere with atherogenesis. The 15(S)-lipoxygenase (15-LOX) plays a janus-role in inflammation with pro-inflammatory and anti-inflammatory effects in cell cultures and primary cells and even opposite effects on atherosclerosis in two different animal species. There is evidence for a pro-atherosclerotic effect of 15-LOX including the direct contribution to LDL oxidation and to the recruitment of monocytes to the vessel wall, its role in angiotensin II mediated mechanisms and in vascular smooth muscle cell proliferation. In contrast to the pro-atherosclerotic effects of 15-LOX, there is also a broad line of evidence that 15-LOX metabolites of arachidonic and linoleic acid have anti-inflammatory effects. The 15-LOX arachidonic acid metabolite 15-HETE inhibits superoxide production and polymorphonuclear neutrophil (PMN) migration across cytokine-activated endothelium and can be further metabolized to the anti-inflammatory lipoxins. These promote vasorelaxation in the aorta and counteract the action of most other pro-inflammatory factors like leukotrienes and prostanoids. Anti-atherogenic properties are also reported for the linoleic acid oxidation product 13-HODE through inhibition of adhesion of several blood cells to the endothelium. Furthermore, there is evidence that 15-LOX is involved in the metabolism of the long-chain omega-3 fatty acid docosahexaenoic acid (DHA) leading to a family of anti-inflammatory resolvins and protectins. From these cell culture and animal studies the role of the 15-LOX in human atherosclerosis cannot be predicted. However, recent genetic studies characterized the 15-LOX haplotypes in Caucasians and discovered a functional polymorphism in the human 15-LOX promoter. This will now allow large studies to investigate an association of 15-LOX with coronary artery disease and to answer the question whether 15-LOX is pro- or anti-atherogenic in humans.
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Affiliation(s)
- Jonas Wittwer
- Institute of Clinical Chemistry, Center for Integrative Human Physiology, University Hospital Zurich, Raemistrasse 100, CH-8091, Zurich, Switzerland
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Weisinger G, Limor R, Marcus-Perlman Y, Knoll E, Kohen F, Schinder V, Firer M, Stern N. 12S-lipoxygenase protein associates with α-actin fibers in human umbilical artery vascular smooth muscle cells. Biochem Biophys Res Commun 2007; 356:554-60. [PMID: 17379189 DOI: 10.1016/j.bbrc.2007.03.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2007] [Accepted: 03/01/2007] [Indexed: 11/29/2022]
Abstract
The current study sets out to characterize the intracellular localization of the platelet-type 12S-lipoxygenase (12-LO), an enzyme involved in angiotensin-II induced signaling in vascular smooth muscle cells (VSMC). Immunohistochemical analysis of VSMC in vitro or human umbilical arteries in vivo showed a clear cytoplasmic localization. On immunogold electron microscopy, 12-LO was found primarily associated with cytoplasmic VSMC muscle fibrils. Upon angiotensin-II treatment of cultured VSMC, immunoprecipitated 12-LO was found bound to alpha-actin, a component of the cytoplasmic myofilaments. 12-LO/alpha-actin binding was blocked by VSMC pretreatment with the 12-LO inhibitors, baicalien or esculetine and the protein synthesis inhibitor, cycloheximide. Moreover, the binding of 12-LO to alpha-actin was not associated with 12-LO serine or tyrosine phosphorylation. These observations suggest a previously unrecognized angiotensin-II dependent protein interaction in VSMC through which 12-LO protein may be trafficked, for yet undiscovered purposes towards the much more abundantly expressed cytoskeletal protein alpha-actin.
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Affiliation(s)
- Gary Weisinger
- Institute of Endocrinology, Metabolism and Hypertension, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Israel.
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33
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Luchtefeld M, Bandlow N, Tietge UJF, Grote K, Pfeilschifter J, Kaszkin M, Beck S, Drexler H, Schieffer B. Angiotensin II type 1-receptor antagonism prevents type IIA secretory phospholipase A2-dependent lipid peroxidation. Atherosclerosis 2006; 194:62-70. [PMID: 17069818 DOI: 10.1016/j.atherosclerosis.2006.09.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2006] [Revised: 09/19/2006] [Accepted: 09/27/2006] [Indexed: 10/24/2022]
Abstract
Accumulation and modification of low density lipoproteins (LDL) within the vessel wall represent key events in atherogenesis. Secretory phospholipase A2 type IIA (sPLA2-IIA) modulates the enzymatic process of LDL-modification and was recently identified as an independent predictor of coronary events in patients with coronary artery disease (CAD). Angiotensin II (ANG II) type 1 (AT1)-receptor blockade reduces LDL-modification and atherosclerotic plaque formation in rodent and primate models of atherosclerosis. Therefore, we assessed whether ANG II via its AT1-receptor enhances sPLA2-IIA-dependent lipid peroxidation in vitro and in patients with CAD. Stimulation of rat aortic smooth muscle cells with ANG II (10(-7) mol/L) enhanced sPLA2-IIA protein expression, activity as well as LDL-peroxidation, determined by western blot, activity assay and malondialdehyde (MDA)-assay and diene formation, respectively, and were blunted by AT1-receptor blockade (Losartan, 10(-5) mol/L). In addition, ANG II-induced sPLA2 activity and LDL-peroxidation were abolished by the sPLA2-IIa activity inhibitor LY311727 (10(-5) mol/L). To evaluate a potential clinical implication, patients (n=18) with angiographically documented CAD were treated with the AT1-receptor blocker Irbesartan (IRB; 300 mg/d) for 12 weeks. Blood samples were obtained from patients pre- and post-treatment and from healthy volunteers. SPLA2-IIA serum level and activity, circulating antibodies against oxidized LDL (oxLDL), oxLDL and MDA were determined in patients and found to be significantly increased compared to healthy volunteers. IRB therapy reduced these markers of inflammation, whereas total cholesterol, HDL- and LDL-fractions remained unchanged. ANG II may elicit pro-atherosclerotic effects via type IIA sPLA2-dependent LDL-modifications. Chronical AT1-receptor blockade reduces sPLA2-IIA level and activity and subsequently lipid peroxidation. Theses findings represent a novel anti-atherosclerotic mechanism and imply that AT1-receptor blockade elicits anti-atherosclerotic potencies even in the absence of plasma cholesterol reduction.
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MESH Headings
- Angiotensin II Type 1 Receptor Blockers/administration & dosage
- Animals
- Aorta/cytology
- Biphenyl Compounds/administration & dosage
- Cells, Cultured
- Coronary Artery Disease/drug therapy
- Coronary Artery Disease/metabolism
- Coronary Artery Disease/pathology
- Enzyme Activation/drug effects
- Enzyme Activation/physiology
- Enzyme Inhibitors/pharmacology
- Female
- Group II Phospholipases A2/antagonists & inhibitors
- Group II Phospholipases A2/blood
- Group II Phospholipases A2/metabolism
- Humans
- Hypertension/drug therapy
- Hypertension/metabolism
- Hypertension/pathology
- Indoles/pharmacology
- Irbesartan
- Lipid Peroxidation/drug effects
- Lipid Peroxidation/physiology
- Lipoproteins, LDL/metabolism
- Losartan/pharmacology
- Male
- Muscle, Smooth, Vascular/cytology
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/enzymology
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptor, Angiotensin, Type 1/genetics
- Receptor, Angiotensin, Type 1/metabolism
- Tetrazoles/administration & dosage
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Affiliation(s)
- Maren Luchtefeld
- Abteilung Kardiologie und Angiologie, Medizinische Hochschule Hannover, D-30625 Hannover, Germany.
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34
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Auerbach ID, Vinters HV. Effects of anoxia and hypoxia on amyloid precursor protein processing in cerebral microvascular smooth muscle cells. J Neuropathol Exp Neurol 2006; 65:610-20. [PMID: 16783171 DOI: 10.1097/00005072-200606000-00009] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Cerebral amyloid angiopathy (CAA) is characterized by the degeneration of cerebral microvascular smooth muscle cells (MV-SMC) and the replacement of normal vessel wall components by beta-amyloid (Abeta) protein. Little is known regarding the mechanisms of SMC degeneration in CAA. The effects of anoxia on the metabolism of the amyloid precursor protein (APP) were studied to investigate the MV-SMC response to anoxic stress and its possible role in the pathogenesis of CAA. MV-SMC exposed to chronic anoxia (24-48 hours) showed a decrease in expression of the 2 putative alpha-secretase enzymes, mature TACE (TNFalpha-converting enzyme) and ADAM10 (a disintegrin and metalloprotease). A concomitant decrease in the alpha-secretase cleavage products sAPPalpha and C83 was observed. Investigation of mRNA expression showed an increase in TACE and a sharp decrease in ADAM10 at 24 hours. Exposing MV-SMC to hypoxia (1% O2) revealed a different pattern of expression with no significant change in TACE protein, but an increase in TACE mRNA occurring at a later time point (48 hours). There was no change in ADAM10 mRNA expression, but a reduction in mature ADAM10 with a parallel increase in immature ADAM10 protein. These results demonstrate a requirement for oxygen in the regulation of the alpha-secretase pathway during APP metabolism.
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Affiliation(s)
- Ilene D Auerbach
- Department of Pathology and Laboratory Medicine (Neuropathology), the Brain Research Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
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35
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Lasaitiene D, Chen Y, Adams MA, Friberg P. Further insights into the role of angiotensin II in kidney development. Clin Physiol Funct Imaging 2006; 26:197-204. [PMID: 16836691 DOI: 10.1111/j.1475-097x.2006.00676.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Over the past decade, compelling studies have highlighted the fundamental role of the renin-angiotensin system (RAS) in renal development and long-term control of renal function and arterial pressure. The present review provides an update of the understanding of how the RAS controls nephrogenesis and nephrovascular development. In addition, the investigations linking the perinatal development of RAS inhibition-induced renal dysmorphology and establishment of adult blood pressure are discussed.
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Affiliation(s)
- Daina Lasaitiene
- Wallenberg Laboratory for Cardiovascular Research, Sahlgrenska University Hospital, University of Gothenburg, Sweden.
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36
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Reinhold SW, Vitzthum H, Filbeck T, Wolf K, Lattas C, Riegger GAJ, Kurtz A, Krämer BK. Gene expression of 5-, 12-, and 15-lipoxygenases and leukotriene receptors along the rat nephron. Am J Physiol Renal Physiol 2006; 290:F864-72. [PMID: 16219916 DOI: 10.1152/ajprenal.00169.2005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The arachidonate signaling pathways comprise prostanoids formed by cyclooxygenases, EETs, and HETEs formed by cytochrome P-450 (CYP) enzymes and HETEs and leukotrienes generated by lipoxygenases. Whereas the intrarenal localization of cyclooxygenases and of some CYP enzymes along the nephron has already been determined, the localization of lipoxygenases and leukotriene-forming enzymes together with leukotriene receptors in the kidney is less clear. This study therefore aimed to determine the expression of 5-, 12-, and 15-lipoxygenases as well as the leukotriene receptors along the rat nephron. The kidneys were dissected into cortex and outer and inner medulla, and the microdissected nephron segments were collected after a collagenase digestion. mRNA abundance was determined by RT-PCR and real-time PCR. 15-LOX mRNA showed a characteristic expression pattern along the distal nephron. 12-LOX mRNA was only found in the glomerulus. Similarly, 5-LOX mRNAs together with 5-LOX-activating protein mRNAs were expressed in the glomerulus and also in the vasa recta. The leukotriene A4 hydrolase was found in all nephron segments, whereas leukotriene C4 synthase mRNA could not be found in any nephron segment. The leukotriene receptor B4 and the cysteinyl leukotriene receptor type 1 were selectively expressed in the glomerulus, whereas cysteinyl receptor type 2 was not found in any nephron segment. Our data suggest that the glomerulus is a major source and target for 5- and 12-HETE and for leukotrienes. The collecting duct system, on the other hand, appears to be a major source of 15-HETE.
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Affiliation(s)
- Stephan W Reinhold
- Klinik und Poliklinik für Innere Medizin II, University of Regensburg, Regensburg, Germany.
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37
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Taylor AM, Hanchett R, Natarajan R, Hedrick CC, Forrest S, Nadler JL, McNamara CA. The effects of leukocyte-type 12/15-lipoxygenase on Id3-mediated vascular smooth muscle cell growth. Arterioscler Thromb Vasc Biol 2005; 25:2069-74. [PMID: 16037566 PMCID: PMC2929383 DOI: 10.1161/01.atv.0000178992.40088.f2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE 12/15-lipoxygenase (12/15-LO) has been implicated in the pathogenesis of vascular disease. Vascular smooth muscle cell (VSMC) proliferation is a key component of the response to injury in vascular disease. The role of 12/15-LO in regulating VSMC proliferation is poorly understood. Id3 has been shown to regulate growth in various cell types and is expressed in VSMCs within atherosclerotic and restenotic lesions. This study examines the role of Id3 in 12/15-LO-mediated VSMC proliferation. METHODS AND RESULTS Primary aortic VSMCs from leukocyte-type 12/15-LO transgenic, leukocyte-type 12/15-LO knockout (KO), and control mice were plated in equal densities and assayed for growth, Id3 protein expression, and Id3 transcription. Results demonstrated that 12/15-LO transgenic VSMCs grew faster, whereas 12/15-LO KO VSMCs grew slower relative to control VSMCs. Further, pharmacological and molecular inhibition of 12/15-LO resulted in decreased VSMC growth. Western blots demonstrated increased Id3 protein in 12/15-LO transgenic VSMCs, whereas luciferase promoter reporter assays revealed increased Id3 transcription. In addition, overexpression of 12/15-LO increased growth in control cells but not in Id3 KO cells. 12/15-LO transgenic VSMCs demonstrated increased protein kinase C (PKC) activity. Consistent with these data, PKC inhibition decreased Id3 promoter activation. CONCLUSIONS 12/15-LO is an important mediator of VSMC growth. The growth-promoting effects of 12/15-LO are at least partially mediated through induction of Id3 transcription.
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Affiliation(s)
- Angela M Taylor
- Cardiovascular Division, University of Virginia Health Sciences Center, Charlottesville, VA 22908, USA
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38
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González-Núñez D, Solé M, Natarajan R, Poch E. 12-Lipoxygenase metabolism in mouse distal convoluted tubule cells. Kidney Int 2005; 67:178-86. [PMID: 15610241 DOI: 10.1111/j.1523-1755.2005.00068.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Several lines of evidence point to the 12-lipoxygenase (12-LOX) family as important mediators in hypertension, diabetes, and other cardiovascular diseases. The kidney has been a main focus for research of the role of this pathway in several disease models. While most of the studies have focused on mesangial or vascular cells, less is known about 12-LOX regulation at the renal tubular level. The aim of the study was to characterize the expression and regulation by hormones of the family of 12-LOX in mouse distal convoluted tubule at the molecular level. METHODS An immortalized mouse distal convoluted tubule (mDCT) cell line was used. mRNA and protein levels were assessed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively, while 12(S)-HETE production was evaluated by enzyme-linked immunosorbent assay (ELISA). Cells were challenged with aldosterone, angiotensin II, 8Br-cAMP, and vasopressin. RESULTS We showed that both platelet (P) and leukocyte (L)-type 12-LOX are expressed in the mDCT cell line, as well as in distal tubules of human kidneys. The production of 12(S)-HETE by mDCT cells was increased in response to cAMP (by two-fold) and by vasopressin (by 1.5-fold). In contrast, neither aldosterone nor angiotensin II exerted appreciable effects on 12(S)-HETE production. The mRNA and protein levels of P-12LOX and L-12LOX were not changed by the different hormones, suggesting that they may act by modulating enzyme activity. We further have demonstrated that this mDCT cell line also expressed the recently cloned 12(R)-LOX. CONCLUSION mDCT cells show an active 12-LOX metabolism that appears to be modulated by cAMP and vasopressin.
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Affiliation(s)
- Daniel González-Núñez
- Servicio de Nefrologia, Laboratorio de Hormonal, Departamento de Anatomia Patologica, Hospital Clinic, Barcelona, Spain
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39
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Tanabe M, Tabuchi S, Iwatsuki M, Kurosaki M, Kamitani H, Yokota M, Watanabe T. Incorporation of arachidonic and linoleic acid hydroperoxides into cultured human umbilical vein endothelial cells. Prostaglandins Leukot Essent Fatty Acids 2004; 70:485-9. [PMID: 15120710 DOI: 10.1016/j.plefa.2003.10.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2003] [Accepted: 10/10/2003] [Indexed: 10/26/2022]
Abstract
The current study assessed the differential incorporation of 12-hydroperoxyeicosatetraenoic acid (12-HPETE), arachidonic acid (AA), 12-hydroxyeicosatetraenoic acid (12-HETE) and the linoleic acid (LA) oxidation products, 13-hydroxyoctadecadienoic acid (13-HODE) and 13-hydroperoxyoctadecadienoic acid (13-HPODE), into human umbilical vein endothelial cells (HUVEC). Approximately 80-90% of AA (10(-8)-10(-5)M) and 80% of LA (10(-8)-10(-5)M) were incorporated into HUVEC within 12h, while less than 50% of the hydroxy metabolites (12-HETE, 12-HPETE, 13-HODE, 13-HPODE) were incorporated into HUVEC over 48h. Further, treatment of HUVEC with either 12-HPETE or 13-HPODE (concentrations of 10(-5)M) had no effect on cell number at a 48h time point when compared with control. These results demonstrate that exogeneous hydroxy metabolites are incorporated into HUVEC to a lesser degree than were endogenous fatty acids. Further, we speculate that 12-HPETE and 13-HPODE are rapidly metabolized to substances without significant cytotoxic effects.
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Affiliation(s)
- Michiharu Tanabe
- Department of Neurosurgery, Institute of Neurological Sciences, Tottori University School of Medicine, 36-1 Nishi-machi, Yonago 683-8504, Japan
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Auerbach ID, Sung SH, Wang Z, Vinters HV. Smooth muscle cells and the pathogenesis of cerebral microvascular disease ("angiomyopathies"). Exp Mol Pathol 2003; 74:148-59. [PMID: 12710946 DOI: 10.1016/s0014-4800(03)00013-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Many forms of human cerebral microvascular disease result from abnormal proliferation and/or degeneration of smooth muscle cells (SMC) in the vessel wall of arteries and arterioles. Human cerebral microvessel-derived smooth muscle cells (MV-SMC) in culture can be used to study the pathogenesis of microvascular disease. Primary cultures were established from nonneoplastic human brain specimens surgically resected and characterized as to their growth properties and phenotype. The cultures have been used to study various factors that may be relevant in the pathogenesis of microangiopathies, in particular cerebral amyloid angiopathy (CAA), to help determine mechanisms of SMC degeneration in these disorders. Factors investigated have included cellular growth rate, response to hypoxia and amyloidogenic peptides, and telomerase activity. MV-SMC appear to behave differently than aortic SMC with regard to proliferation and telomerase activity. These differences may play a role in the responses to MV-SMC in the evolution of CAA and other microangiopathies (cerebral arteriosclerosis/lipohyalinosis) and provide insight into mechanisms of degeneration of these cells within vessel walls.
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Affiliation(s)
- Ilene D Auerbach
- Department of Pathology & Laboratory Medicine (Neuropathology), David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
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41
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Alpert E, Gruzman A, Totary H, Kaiser N, Reich R, Sasson S. A natural protective mechanism against hyperglycaemia in vascular endothelial and smooth-muscle cells: role of glucose and 12-hydroxyeicosatetraenoic acid. Biochem J 2002; 362:413-22. [PMID: 11853550 PMCID: PMC1222402 DOI: 10.1042/0264-6021:3620413] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Bovine aortic endothelial and smooth-muscle cells down-regulate the rate of glucose transport in the face of hyperglycaemia, thus providing protection against deleterious effects of increased intracellular glucose levels. When exposed to high glucose concentrations these cells reduced the mRNA and protein content of their typical glucose transporter, GLUT-1, as well as its plasma-membrane abundance. Inhibition of the lipoxygenase (LO) pathway, and particularly 12-LO, reversed this glucose-induced down-regulatory process and restored the rate of hexose transport to the level seen in vascular cells exposed to normal glucose levels. This reversal was accompanied by increased levels of GLUT-1 mRNA and protein, as well as of its plasma-membrane content. Exposure of the vascular cells to elevated glucose concentrations increased by 2-3-fold the levels of cell-associated and secreted 12-hydroxyeicosatetraenoic acid (12-HETE), the product of 12-LO. Inhibition of 15- and 5-LO, cyclo-oxygenases 1 and 2, and eicosanoid-producing cytochrome P450 did not modify the hexose-transport system in vascular cells. These results suggest a role for HETEs in the autoregulation of hexose transport in vascular cells. 8-Iso prostaglandin F(2alpha), a non-enzymic oxidation product of arachidonic acid, had no effect on the hexose-transport system in vascular cells exposed to hyperglycaemic conditions. Taken together, these findings show that hyperglycaemia increases the production rate of 12-HETE, which in turn mediates the down-regulation of GLUT-1 expression and the glucose-transport system in vascular endothelial and smooth-muscle cells.
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MESH Headings
- 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid/pharmacology
- Animals
- Antioxidants/pharmacology
- Biological Transport/drug effects
- Cattle
- Cell Membrane/metabolism
- Cells, Cultured
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Gene Expression Regulation/drug effects
- Glucose/pharmacology
- Glucose Transporter Type 1
- Hyperglycemia/prevention & control
- Kinetics
- Monosaccharide Transport Proteins/drug effects
- Monosaccharide Transport Proteins/genetics
- Monosaccharide Transport Proteins/metabolism
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Umbelliferones/pharmacology
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Affiliation(s)
- Evgenia Alpert
- Department of Pharmacology, School of Pharmacy, Faculty of Medicine, The Hebrew University School of Medicine, P.O. Box 12272, Jerusalem 91120, Israel
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Xu W, Takahashi Y, Sakashita T, Iwasaki T, Hattori H, Yoshimoto T. Low density lipoprotein receptor-related protein is required for macrophage-mediated oxidation of low density lipoprotein by 12/15-lipoxygenase. J Biol Chem 2001; 276:36454-9. [PMID: 11479307 DOI: 10.1074/jbc.m105093200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The oxidative modification of low density lipoprotein (LDL) has been implicated in the early stage of atherosclerosis through multiple potential pathways, and 12/15-lipoxygenase is suggested to be involved in this oxidation process. We demonstrated previously that the 12/15-lipoxygenase overexpressed in mouse macrophage-like J774A.1 cells was required for the cell-mediated LDL oxidation. However, the mechanism of the oxidation of extracellular LDL by the intracellular 12/15-lipoxygenase has not yet been elucidated. In the present study, we found that not only the LDL receptor but also LDL receptor-related protein (LRP), both of which are cell surface native LDL-binding receptors, were down-regulated by the preincubation of the cells with cholesterol or LDL and up-regulated by lipoprotein-deficient serum. Moreover, 12/15-lipoxygenase-expressing cell-mediated LDL oxidation was decreased by the preincubation of the cells with LDL or cholesterol and increased by the preincubation with lipoprotein-deficient serum. Heparin-binding protein 44, an antagonist of the LDL receptor family, also suppressed the cell-mediated LDL oxidation in a dose-dependent manner. The cell-mediated LDL oxidation was dose-dependently blocked by an anti-LRP antibody but not by an anti-LDL receptor antibody. Furthermore, antisense oligodeoxyribonucleotides against LRP reduced the cell-mediated LDL oxidation under the conditions in which the expression of LRP was decreased. The results taken together indicate that LRP was involved essentially for the cell-mediated LDL oxidation by 12/15-lipoxygenase expressed in J774A.1 cells, suggesting an important pathophysiological role of this receptor-enzyme system as the initial trigger of the progression of atherosclerosis.
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Affiliation(s)
- W Xu
- Department of Molecular Pharmacology, Kanazawa University Graduate School of Medicine, Kanazawa 920-8640, Japan
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Gu J, Liu Y, Wen Y, Natarajan R, Lanting L, Nadler JL. Evidence that increased 12-lipoxygenase activity induces apoptosis in fibroblasts. J Cell Physiol 2001; 186:357-65. [PMID: 11169974 DOI: 10.1002/1097-4652(200103)186:3<357::aid-jcp1034>3.0.co;2-e] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The 12-lipoxygenase (LO) enzyme has been implicated in playing a role in pancreatic beta cell inflammatory damage and atherosclerosis. 12-LO reacts with fatty acids to form hydroperoxides which may alter cellular growth. In this study we investigated the direct effect of mouse leukocyte type 12-LO cDNA overexpression on apoptosis in Chinese hamster ovary fibroblast cells that also stably overexpress the angiotensin II type 1a receptor. CHO-AT1a cells expressing background levels of 12-LO exhibited clear increases in growth in response to angiotensin II. In contrast, the new 12-LO transfected cells (CHO-AT1a/ML12-LO cells) displayed reduced basal and angiotensin Il-induced growth compared to CHO-AT1a cells. Furthermore, serum-deprivation resulted in a significantly greater number of non-viable cells in clones having the greatest magnitude of 12-LO overexpression. These results suggested that reduction of the proliferation rate of CHO-AT1a/ML12-LO cells was due to an increasing rate of cell death. To determine whether the increase in cell death was due to apoptosis, we evaluated nuclear DNA fragmentation, cell morphologic changes, and activation of caspase-3. Cells overexpressing 12-LO cDNA displayed all these changes characteristic of apoptosis. In addition the 12-LO product, 12-hydroperoxyeicosatetraenoic acid (12-HPETE), directly induced apoptosis in CHO-AT1a cells. These results demonstrate for the first time that 12-LO activation can lead to apoptosis in fibroblasts, suggesting a role of 12-LO in leading to inflammatory mediated cellular damage.
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Affiliation(s)
- J Gu
- Department of Internal Medicine, Division of Endocrinology and Metabolism, University of Virginia, School of Medicine, MR 4 Building, Charlottesville, VA 22908, USA
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Zhu M, Natarajan R, Nadler JL, Moore JM, Gelband CH, Sumners C. Angiotensin II increases neuronal delayed rectifier K(+) current: role of 12-lipoxygenase metabolites of arachidonic acid. J Neurophysiol 2000; 84:2494-501. [PMID: 11067992 DOI: 10.1152/jn.2000.84.5.2494] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Angiotensin II (Ang II) elicits an Ang II type 2 (AT(2)) receptor-mediated increase in voltage-dependent delayed rectifier K(+) current (I(KV)) in neurons cultured from newborn rat hypothalamus and brain stem. In previous studies, we have determined that this effect of Ang II is mediated via a Gi protein, activation of phospholipase A(2) (PLA(2)), and generation of arachidonic acid (AA). AA is rapidly metabolized within cells via lipoxygenases (LO), cyclooxygenase (COX) or p450 monooxygenase enzymes, and the metabolic products are known regulators of K(+) currents and channels. Thus in the present study, we have investigated whether the AT(2) receptor-mediated effects of Ang II on neuronal I(KV) require AA metabolism and if so, which metabolic pathways are involved. The data presented here indicate that the stimulatory actions of Ang II and AA on neuronal I(KV) are attenuated by selective blockade of 12-LO enzymes. However, the effects of Ang II are not altered by blockade of 5-LO or p450 monooxygenase enzymes. Furthermore, the actions of Ang II are mimicked by a 12-LO metabolite of AA, but 5-LO metabolites such as leukotriene B(4) and C(4) do not alter neuronal I(KV). These data indicate that the AT(2) receptor-mediated stimulation of neuronal I(KV) is partially mediated through 12-LO metabolites of AA.
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MESH Headings
- 5,8,11,14-Eicosatetraynoic Acid/pharmacology
- Angiotensin II/pharmacology
- Animals
- Antibodies/pharmacology
- Arachidonate 12-Lipoxygenase/immunology
- Arachidonate 12-Lipoxygenase/metabolism
- Arachidonic Acid/metabolism
- Brain Stem/cytology
- Cells, Cultured
- Delayed Rectifier Potassium Channels
- Flavanones
- Flavonoids/pharmacology
- Free Radical Scavengers/pharmacology
- Hypothalamus/cytology
- Indoles/pharmacology
- Lipoxygenase Inhibitors/pharmacology
- Membrane Potentials/drug effects
- Membrane Potentials/physiology
- Neurons/chemistry
- Neurons/cytology
- Neurons/metabolism
- Patch-Clamp Techniques
- Potassium Channels/physiology
- Potassium Channels, Voltage-Gated
- Rats
- Rats, Sprague-Dawley
- Receptor, Angiotensin, Type 1
- Receptor, Angiotensin, Type 2
- Receptors, Angiotensin/metabolism
- Signal Transduction/physiology
- Vasoconstrictor Agents/pharmacology
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Affiliation(s)
- M Zhu
- Department of Physiology, College of Medicine and University of Florida Brain Institute, University of Florida, Gainesville, Florida 32610, USA
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Abstract
Angiogenesis, the formation of new capillaries from preexisting blood vessels, is a multistep, highly orchestrated process involving vessel sprouting, endothelial cell migration, proliferation, tube differentiation, and survival. Eicosanoids, arachidonic acid (AA)-derived metabolites, have potent biologic activities on vascular endothelial cells. Endothelial cells can synthesize various eicosanoids, including the 12-lipoxygenase (LOX) product 12(S)-hydroxyeicosatetraenoic acid (HETE). Here we demonstrate that endogenous 12-LOX is involved in endothelial cell angiogenic responses. First, the 12-LOX inhibitor, N-benzyl-N-hydroxy-5-phenylpentanamide (BHPP), reduced endothelial cell proliferation stimulated either by basic fibroblast growth factor (bFGF) or by vascular endothelial growth factor (VEGF). Second, 12-LOX inhibitors blocked VEGF-induced endothelial cell migration, and this blockage could be partially reversed by the addition of 12(S)-HETE. Third, pretreatment of an angiogenic endothelial cell line, RV-ECT, with BHPP significantly inhibited the formation of tubelike/cordlike structures within Matrigel. Fourth, overexpression of 12-LOX in the CD4 endothelial cell line significantly stimulated cell migration and tube differentiation. In agreement with the critical role of 12-LOX in endothelial cell angiogenic responses in vitro, the 12-LOX inhibitor BHPP significantly reduced bFGF-induced angiogenesis in vivo using a Matrigel implantation bioassay. These findings demonstrate that AA metabolism in endothelial cells, especially the 12-LOX pathway, plays a critical role in angiogenesis.
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Abstract
AbstractAngiogenesis, the formation of new capillaries from preexisting blood vessels, is a multistep, highly orchestrated process involving vessel sprouting, endothelial cell migration, proliferation, tube differentiation, and survival. Eicosanoids, arachidonic acid (AA)-derived metabolites, have potent biologic activities on vascular endothelial cells. Endothelial cells can synthesize various eicosanoids, including the 12-lipoxygenase (LOX) product 12(S)-hydroxyeicosatetraenoic acid (HETE). Here we demonstrate that endogenous 12-LOX is involved in endothelial cell angiogenic responses. First, the 12-LOX inhibitor, N-benzyl-N-hydroxy-5-phenylpentanamide (BHPP), reduced endothelial cell proliferation stimulated either by basic fibroblast growth factor (bFGF) or by vascular endothelial growth factor (VEGF). Second, 12-LOX inhibitors blocked VEGF-induced endothelial cell migration, and this blockage could be partially reversed by the addition of 12(S)-HETE. Third, pretreatment of an angiogenic endothelial cell line, RV-ECT, with BHPP significantly inhibited the formation of tubelike/cordlike structures within Matrigel. Fourth, overexpression of 12-LOX in the CD4 endothelial cell line significantly stimulated cell migration and tube differentiation. In agreement with the critical role of 12-LOX in endothelial cell angiogenic responses in vitro, the 12-LOX inhibitor BHPP significantly reduced bFGF-induced angiogenesis in vivo using a Matrigel implantation bioassay. These findings demonstrate that AA metabolism in endothelial cells, especially the 12-LOX pathway, plays a critical role in angiogenesis.
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Thiele BJ, Berger M, Thiele H, Huth A, Reimann I. Features of mammalian lipoxygenases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2000; 469:61-6. [PMID: 10667311 DOI: 10.1007/978-1-4615-4793-8_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Affiliation(s)
- B J Thiele
- Institute of Biochemistry, University Clinics Charité, Humboldt-University, Berlin, Germany
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Hedrick CC, Kim MD, Natarajan RD, Nadler JL. 12-Lipoxygenase products increase monocyte:endothelial interactions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2000; 469:455-60. [PMID: 10667368 DOI: 10.1007/978-1-4615-4793-8_67] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In summary, we suggest that hyperglycemia causes upregulation of 12-lipoxygenase activity. The increased production of 12-LO products, 12(S) and 15(S)-HETE, activates monocyte integrins which result in enhanced adhesion of monocytes to endothelium. The binding of monocytes to endothelium is a key early event in development of atherosclerosis. Upregulation of this process by vascular cells exposed to chronic elevations in glucose may be one explanation for the accelerated atherosclerosis observed in patients with Type 2 diabetes.
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Affiliation(s)
- C C Hedrick
- Division of Cardiology, University of California Los Angeles 90095, USA
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Sasson S, Davarashvili A, Reich R. Role of lipoxygenase in the regulation of glucose transport in aortic vascular cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2000; 469:377-83. [PMID: 10667356 DOI: 10.1007/978-1-4615-4793-8_55] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
MESH Headings
- Animals
- Arachidonic Acid/metabolism
- Arteriosclerosis/etiology
- Arteriosclerosis/metabolism
- Biological Transport, Active/drug effects
- Cattle
- Cell Division
- Cells, Cultured
- Cyclooxygenase Inhibitors/pharmacology
- Diabetes Complications
- Diabetes Mellitus/metabolism
- Diabetic Angiopathies/etiology
- Diabetic Angiopathies/metabolism
- Endothelium, Vascular/cytology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Glucose/metabolism
- Humans
- Hyperglycemia/complications
- Hyperglycemia/metabolism
- Lipoxygenase/metabolism
- Lipoxygenase Inhibitors/pharmacology
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Umbelliferones/pharmacology
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Affiliation(s)
- S Sasson
- Department of Pharmacology, School of Pharmacy, Faculty of Medicine, Hebrew University, Jerusalem, Israel
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