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Ning Y, Jia Y, Yang Y, Wen W, Huang M, Liu S, Yang Y, Dong Y, Zhang M. Thyroid hormones inhibit apoptosis of macrophage induced by oxidized low-density lipoprotein. Biofactors 2022; 48:86-99. [PMID: 34882872 DOI: 10.1002/biof.1803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 10/19/2021] [Indexed: 12/12/2022]
Abstract
Increasing evidence suggests that hypothyroidism aggravates atherosclerosis. Macrophage apoptosis plays a significant role in the development of atherosclerotic plaque. We aimed to explore the effect of thyroid hormones on macrophage apoptosis induced by oxidized low-density lipoprotein (oxLDL). Peripheral blood samples from 20 patients (normal group, hypothyroidism group, coronary artery disease [CAD] group, hypothyroidism + CAD group) were collected to perform messenger RNA microarray analysis. Bioinformatics analysis identified apoptosis and mitogen-activated protein kinase (MAPK) signaling as differentially expressed pathways between CAD and hypothyroidism + CAD group. In vitro, thyroid hormones concentration-dependently promoted cell survival and inhibited apoptosis in oxLDL-treated RAW264.7 macrophages, along with elevated extracellular signal-regulated kinases 1 and 2 (Erk1/2) phosphorylation. The STRING database showed an interaction of thyroid hormone receptor alpha1 (TRα1) and MAPK pathway. TRα1 knockdown increased cell apoptosis and decreased Erk1/2 phosphorylation. Erk1/2 inhibitor aggravated macrophage apoptosis. Moreover, thyroid hormones inhibited oxidative stress in oxLDL-treated macrophages. The study indicates that thyroid hormones concentration-dependently attenuate oxLDL-induced macrophage apoptosis through activating TRα1-Erk1/2 pathway and inhibiting oxidative stress, which implies a potential mechanism of hypothyroid-accelerated atherosclerosis.
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Affiliation(s)
- Yu Ning
- Department of Cardiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- National Health Commission Key Laboratory of Assisted Circulation, Sun Yat-sen University, Guangzhou, China
- National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Sun Yat-sen University, Guangzhou, China
- State Key Laboratory of Cardiovascular Diseases, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Yifan Jia
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Yunxiao Yang
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Wanwan Wen
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Mengling Huang
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Sheng Liu
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Yuejin Yang
- State Key Laboratory of Cardiovascular Diseases, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yugang Dong
- Department of Cardiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- National Health Commission Key Laboratory of Assisted Circulation, Sun Yat-sen University, Guangzhou, China
- National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Sun Yat-sen University, Guangzhou, China
| | - Ming Zhang
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
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Marques ARA, Ramos C, Machado-Oliveira G, Vieira OV. Lysosome (Dys)function in Atherosclerosis-A Big Weight on the Shoulders of a Small Organelle. Front Cell Dev Biol 2021; 9:658995. [PMID: 33855029 PMCID: PMC8039146 DOI: 10.3389/fcell.2021.658995] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/11/2021] [Indexed: 12/15/2022] Open
Abstract
Atherosclerosis is a progressive insidious chronic disease that underlies most of the cardiovascular pathologies, including myocardial infarction and ischemic stroke. The malfunctioning of the lysosomal compartment has a central role in the etiology and pathogenesis of atherosclerosis. Lysosomes are the degradative organelles of mammalian cells and process endogenous and exogenous substrates in a very efficient manner. Dysfunction of these organelles and consequent inefficient degradation of modified low-density lipoproteins (LDL) and apoptotic cells in atherosclerotic lesions have, therefore, numerous deleterious consequences for cellular homeostasis and disease progression. Lysosome dysfunction has been mostly studied in the context of the inherited lysosomal storage disorders (LSDs). However, over the last years it has become increasingly evident that the consequences of this phenomenon are more far-reaching, also influencing the progression of multiple acquired human pathologies, such as neurodegenerative diseases, cancer, and cardiovascular diseases (CVDs). During the formation of atherosclerotic plaques, the lysosomal compartment of the various cells constituting the arterial wall is under severe stress, due to the tremendous amounts of lipoproteins being processed by these cells. The uncontrolled uptake of modified lipoproteins by arterial phagocytic cells, namely macrophages and vascular smooth muscle cells (VSMCs), is the initial step that triggers the pathogenic cascade culminating in the formation of atheroma. These cells become pathogenic "foam cells," which are characterized by dysfunctional lipid-laden lysosomes. Here, we summarize the current knowledge regarding the origin and impact of the malfunctioning of the lysosomal compartment in plaque cells. We further analyze how the field of LSD research may contribute with some insights to the study of CVDs, particularly how therapeutic approaches that target the lysosomes in LSDs could be applied to hamper atherosclerosis progression and associated mortality.
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Affiliation(s)
- André R A Marques
- iNOVA4Health, Chronic Diseases Research Center (CEDOC), NOVA Medical School (NMS), Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Cristiano Ramos
- iNOVA4Health, Chronic Diseases Research Center (CEDOC), NOVA Medical School (NMS), Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Gisela Machado-Oliveira
- iNOVA4Health, Chronic Diseases Research Center (CEDOC), NOVA Medical School (NMS), Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Otília V Vieira
- iNOVA4Health, Chronic Diseases Research Center (CEDOC), NOVA Medical School (NMS), Universidade NOVA de Lisboa, Lisbon, Portugal
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He X, Fan X, Bai B, Lu N, Zhang S, Zhang L. Pyroptosis is a critical immune-inflammatory response involved in atherosclerosis. Pharmacol Res 2021; 165:105447. [PMID: 33516832 DOI: 10.1016/j.phrs.2021.105447] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/28/2020] [Accepted: 01/17/2021] [Indexed: 02/07/2023]
Abstract
Pyroptosis is a form of programmed cell death activated by various stimuli and is characterized by inflammasome assembly, membrane pore formation, and the secretion of inflammatory cytokines (IL-1β and IL-18). Atherosclerosis-related risk factors, including oxidized low-density lipoprotein (ox-LDL) and cholesterol crystals, have been shown to promote pyroptosis through several mechanisms that involve ion flux, ROS, endoplasmic reticulum stress, mitochondrial dysfunction, lysosomal rupture, Golgi function, autophagy, noncoding RNAs, post-translational modifications, and the expression of related molecules. Pyroptosis of endothelial cells, macrophages, and smooth muscle cells in the vascular wall can induce plaque instability and accelerate atherosclerosis progression. In this review, we focus on the pathogenesis, influence, and therapy of pyroptosis in atherosclerosis and provide novel ideas for suppressing pyroptosis and the progression of atherosclerosis.
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Affiliation(s)
- Xiao He
- Department of Neurology, First Affiliated Hospital of Harbin Medical University, 23 You Zheng Street, Harbin 150001, Heilongjiang Province, China.
| | - Xuehui Fan
- Department of Neurology, First Affiliated Hospital of Harbin Medical University, 23 You Zheng Street, Harbin 150001, Heilongjiang Province, China.
| | - Bing Bai
- Department of Neurology, First Affiliated Hospital of Harbin Medical University, 23 You Zheng Street, Harbin 150001, Heilongjiang Province, China.
| | - Nanjuan Lu
- Department of Neurology, First Affiliated Hospital of Harbin Medical University, 23 You Zheng Street, Harbin 150001, Heilongjiang Province, China.
| | - Shuang Zhang
- General Surgery, Harbin Changzheng Hospital, 363 Xuan Hua Street, Harbin 150001, Heilongjiang Province, China.
| | - Liming Zhang
- Department of Neurology, First Affiliated Hospital of Harbin Medical University, 23 You Zheng Street, Harbin 150001, Heilongjiang Province, China.
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4
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Tie G, Yan J, Messina JA, Raffai RL, Messina LM. Inhibition of p38 Mitogen-Activated Protein Kinase Enhances the Apoptosis Induced by Oxidized Low-Density Lipoprotein in Endothelial Progenitor Cells. J Vasc Res 2016; 52:361-71. [PMID: 27031525 DOI: 10.1159/000443889] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 01/10/2016] [Indexed: 11/19/2022] Open
Abstract
Oxidized low-density lipoprotein (oxLDL) is an important risk factor in the development of atherosclerosis. oxLDL has been shown to decrease endothelial progenitor cell (EPC) number by inducing apoptosis. p38 mitogen-activated protein kinase (MAPK) was shown to be activated by oxLDL and participated in the regulation of EPC number and function. However, the role of p38 remains unknown. Here, we show that oxLDL-induced p38 phosphorylation in EPCs is time and dose dependent. Treatment with antioxidant N-acetyl cysteine restored oxLDL-induced p38 phosphorylation to basal levels. LOX-1-blocking antibody also significantly decreased oxLDL-induced p38 phosphorylation. Interestingly, TUNEL staining showed that pretreatment with the p38 inhibitor SB203580 further increased oxLDL-induced apoptosis in EPCs. In accordance with these findings, pretreatment with SB203580 further attenuated Akt phosphorylation in EPCs challenged with oxLDL, indicating an interaction between Akt and p38 MAPK pathways. In agreement, inhibition of p38 MAPK further attenuated Akt phosphorylation and increased apoptosis in EPCs isolated from hypercholesterolemic ApoE-/- mice. In conclusion, p38 MAPK serves as an anti-apoptotic pathway by supporting Akt activity when EPCs are challenged with oxLDL.
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Affiliation(s)
- Guodong Tie
- Division of Vascular Surgery, University of Massachusetts Medical School, Worcester, Mass., USA
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5
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Marques L, Negre-Salvayre A, Costa L, Canonne-Hergaux F. Iron gene expression profile in atherogenic Mox macrophages. Biochim Biophys Acta Mol Basis Dis 2016; 1862:1137-46. [PMID: 26972048 DOI: 10.1016/j.bbadis.2016.03.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 03/08/2016] [Accepted: 03/09/2016] [Indexed: 02/06/2023]
Abstract
RATIONALE The role of macrophage iron in the physiopathology of atherosclerosis is an open question that needs to be clarified. In atherosclerotic lesions, recruited macrophages are submitted to cytokines and oxidized lipids which influence their phenotype. An important phenotypic population driven by oxidized phospholipids is the Mox macrophages which present unique biological properties but their iron phenotype is not well described. OBJECTIVE To investigate the effect of Mox polarization by oxidized LDL (oxLDL) on macrophage iron metabolism in the absence or presence of proinflammatory stimuli. METHODS Bone marrow-derived macrophages were treated with different sources of LDL and/or LPS/IFNγ (M1 activator). Expression of ferroportin (Slc40a1, alias Fpn), heme oxygenase-1 (Hmox1), H- and L-ferritin (Fth1 and Ftl1), hepcidin (Hamp), ceruloplasmin (Cp) and interleukine-6 (Il6) was followed by quantitative PCR. FPN and HMOX1 protein expression was analyzed by immunofluorescence and in-cell-Western blotting. RESULTS Mox macrophages expressed increased Hmox1 and Fth1 levels with basal FPN protein levels despite the significant increase of Fpn mRNA. Upregulation of Hmox1 and Fpn mRNA was specific to LDL oxidative modification and mediated by NRF2. The downregulation of both Cp isoforms and the upregulation of Hamp expression observed in Mox macrophages suggest that FPN mediated iron export could be compromised. Simultaneous exposure to oxLDL and LPS/IFNγ leads to a mixed Mox/M1 phenotype that is closer to M1. CONCLUSION A microenvironment rich in oxLDL and proinflammatory cytokines could promote macrophage iron retention and lipid accumulation profiles, a specific cell phenotype that likely contributes to lesion development and plaque instability in atherosclerosis.
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Affiliation(s)
- Liliana Marques
- INSERM UMR 1043, CNRS UMR 5282, Université de Toulouse, UPS, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France; Departamento da Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisboa, Portugal; University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, Lisboa, Portugal
| | | | - Luciana Costa
- Departamento da Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisboa, Portugal; University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, Lisboa, Portugal.
| | - François Canonne-Hergaux
- INSERM UMR 1043, CNRS UMR 5282, Université de Toulouse, UPS, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France; IRSD, Université de Toulouse, INSERM, INRA, INP-ENVT, Université de Toulouse 3 Paul Sabatier, Toulouse, France.
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Iron-Mediated Lysosomal Membrane Permeabilization in Ethanol-Induced Hepatic Oxidative Damage and Apoptosis: Protective Effects of Quercetin. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2016:4147610. [PMID: 27057276 PMCID: PMC4707336 DOI: 10.1155/2016/4147610] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 10/27/2015] [Accepted: 11/04/2015] [Indexed: 01/21/2023]
Abstract
Iron, in its free ferrous states, can catalyze Fenton reaction to produce OH∙, which is recognized as a crucial role in the pathogenesis of alcoholic liver diseases (ALD). As a result of continuous decomposition of iron-containing compounds, lysosomes contain a pool of redox-active iron. To investigate the important role of intralysosomal iron in alcoholic liver injury and the potential protection of quercetin, male C57BL/6J mice fed by Lieber De Carli diets containing ethanol (30% of total calories) were cotreated by quercetin or deferoxamine (DFO) for 15 weeks and ethanol-incubated mice primary hepatocytes were pretreated with FeCl3, DFO, and bafilomycin A1 at their optimal concentrations and exposure times. Chronic ethanol consumption caused an evident increase in lysosomal redox-active iron accompanying sustained oxidative damage. Iron-mediated ROS could trigger lysosomal membrane permeabilization (LMP) and subsequent mitochondria apoptosis. The hepatotoxicity was attenuated by reducing lysosomal iron while being exacerbated by escalating lysosomal iron. Quercetin substantially alleviated the alcoholic liver oxidative damage and apoptosis by decreasing lysosome iron and ameliorating iron-mediated LMP, which provided a new prospective of the use of quercetin against ALD.
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Kurz T, Eaton JW, Brunk UT. The role of lysosomes in iron metabolism and recycling. Int J Biochem Cell Biol 2011; 43:1686-97. [PMID: 21907822 DOI: 10.1016/j.biocel.2011.08.016] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 08/25/2011] [Accepted: 08/26/2011] [Indexed: 02/07/2023]
Abstract
Iron is the most abundant transition metal in the earth's crust. It cycles easily between ferric (oxidized; Fe(III)) and ferrous (reduced; Fe(II)) and readily forms complexes with oxygen, making this metal a central player in respiration and related redox processes. However, 'loose' iron, not within heme or iron-sulfur cluster proteins, can be destructively redox-active, causing damage to almost all cellular components, killing both cells and organisms. This may explain why iron is so carefully handled by aerobic organisms. Iron uptake from the environment is carefully limited and carried out by specialized iron transport mechanisms. One reason that iron uptake is tightly controlled is that most organisms and cells cannot efficiently excrete excess iron. When even small amounts of intracellular free iron occur, most of it is safely stored in a non-redox-active form in ferritins. Within nucleated cells, iron is constantly being recycled from aged iron-rich organelles such as mitochondria and used for construction of new organelles. Much of this recycling occurs within the lysosome, an acidic digestive organelle. Because of this, most lysosomes contain relatively large amounts of redox-active iron and are therefore unusually susceptible to oxidant-mediated destabilization or rupture. In many cell types, iron transit through the lysosomal compartment can be remarkably brisk. However, conditions adversely affecting lysosomal iron handling (or oxidant stress) can contribute to a variety of acute and chronic diseases. These considerations make normal and abnormal lysosomal handling of iron central to the understanding and, perhaps, therapy of a wide range of diseases.
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Affiliation(s)
- Tino Kurz
- Division of Pharmacology, Faculty of Health Sciences, Linköping University, 581 85 Linköping, Sweden.
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Floegel A, Kim DO, Chung SJ, Song WO, Fernandez ML, Bruno RS, Koo SI, Chun OK. Development and validation of an algorithm to establish a total antioxidant capacity database of the US diet. Int J Food Sci Nutr 2010; 61:600-23. [PMID: 20377495 DOI: 10.3109/09637481003670816] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Estimation of total antioxidant intake is the first step to investigate the protective effects of antioxidants on oxidative stress-mediated disease. The present study was designed to develop an algorithm to estimate total antioxidant capacity (TAC) of the US diet. TAC of individual antioxidants and 50 popular antioxidant-rich food items in the US diet were determined by 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) assay and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Theoretical TAC of foods was calculated as the sum of individual antioxidant capacities of compounds. The top 10 TAC food items in the US diet according to standard serving size were blueberry > plum > green tea > strawberry > green tea (decaffeinated) > red wine > grape juice > black tea > cherry > grape. Major contributors to TAC were the total phenolic content (r = 0.952, P < 0.001) and flavonoid content (r = 0.827, P < 0.001) of 50 foods. Theoretical TAC was positively correlated to experimental TAC of 50 foods determined by the ABTS assay (r = 0.833, P < 0.001) and the DPPH assay (r = 0.696, P < 0.001), and to TAC from the USDA database for the oxygen radical absorbance capacity (r = 0.484, P = 0.001, n = 44). The TAC database of the US diet has been established and validated. In future studies, TAC of the US diet can be linked to biomarkers of chronic disease.
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Affiliation(s)
- Anna Floegel
- Department of Nutritional Sciences, University of Connecticut, Storrs, Connecticut 06269-4017, USA
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Gieseg SP, Amit Z, Yang YT, Shchepetkina A, Katouah H. Oxidant production, oxLDL uptake, and CD36 levels in human monocyte–derived macrophages are downregulated by the macrophage-generated antioxidant 7,8-dihydroneopterin. Antioxid Redox Signal 2010; 13:1525-34. [PMID: 20408759 DOI: 10.1089/ars.2009.3065] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The severity of atheroma burden in patients strongly correlates to increasing levels of plasma neopterin, the oxidation product of 7,8-dihydroneopterin. Interferon-γ stimulation of macrophages causes the synthesis of 7,8-dihydroneopterin, a potent antioxidant that inhibits oxidative damage to cells, and the cytotoxicity of oxidized low-density lipoprotein (oxLDL) to monocyte-like U937 cells but not THP-1 cells. With human monocyte-derived macrophages (HMDMs), oxLDL triggered a large oxidative stress, causing the rapid loss of cellular glutathione, glyceradehyde-3-phosphate dehydrogenase (GAPDH) inhibition, and eventual loss of viability without caspase-3 activation. Inhibition of oxLDL cytotoxicity to HMDMs occurred at 7,8-dihydroneopterin concentrations >100 μM. The oxLDL-mediated glutathione loss and GAPDH inactivation was inhibited by 7,8-dihydroneopterin. 7,8-Dihydroneopterin rapidly entered the HMDMs, suggesting that much of the protective effect was scavenging of intracellular oxidants generated in response to oxLDL. OxLDL uptake by HMDMs was reduced by 30% by 7,8-dihydroneopterin. Immunoblot analysis suggests that this decrease in oxLDL uptake was due to a significant downregulation in the levels of CD36. These results imply that 7,8-dihydroneopterin protects human macrophages both by scavenging oxidants generated in response to oxLDL and by decreasing CD36-mediated uptake of oxLDL.
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Affiliation(s)
- Steven P Gieseg
- Free Radical Biochemistry Laboratory, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.
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Smith KJ, Twal WO, Soodavar F, Virella G, Lopes-Virella MF, Hammad SM. Heat shock protein 70B' (HSP70B') expression and release in response to human oxidized low density lipoprotein immune complexes in macrophages. J Biol Chem 2010; 285:15985-93. [PMID: 20348092 DOI: 10.1074/jbc.m110.113605] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Heat shock proteins (HSPs) have been implicated in the activation and survival of macrophages. This study examined the role of HSP70B', a poorly characterized member of the HSP70 family, in response to oxidatively modified LDL (oxLDL) and immune complexes prepared with human oxLDL and purified human antibodies to oxLDL (oxLDL-IC) in monocytic and macrophage cell lines. Immunoblot analysis of cell lysates and conditioned medium from U937 cells treated with oxLDL alone revealed an increase in intracellular HSP70B' protein levels accompanied by a concomitant increase in HSP70B' extracellular levels. Fluorescence immunohistochemistry and confocal microscopy, however, demonstrated that oxLDL-IC stimulated the release of HSP70B', which co-localized with cell-associated oxLDL-IC. In HSP70B'-green fluorescent protein-transfected mouse RAW 264.7 cells, oxLDL-IC-induced HSP70B' co-localized with membrane-associated oxLDL-IC as well as the lipid moiety of internalized oxLDL-IC. Furthermore, the data demonstrated that HSP70B' is involved in cell survival, and this effect could be mediated by sphingosine kinase 1 (SK1) activation. An examination of regularly implicated cytokines revealed a significant relationship between HSP70B' and the release of the anti-inflammatory cytokine interleukin-10 (IL-10). Small interfering RNA knockdown of HSP70B' resulted in a corresponding decrease in SK1 mRNA levels and SK1 phosphorylation as well as increased release of IL-10. In conclusion, these findings suggest that oxLDL-IC induce the synthesis and release of HSP70B', and once stimulated, HSP70B' binds to the cell-associated and internalized lipid moiety of oxLDL-IC. The data also implicate HSP70B' in key cellular functions, such as regulation of SK1 activity and release of IL-10, which influence macrophage activation and survival.
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Affiliation(s)
- Kent J Smith
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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Bai Q, Li X, Ning Y, Zhao F, Yin L. Mitochondrial cholesterol transporter, StAR, inhibits human THP-1 monocyte-derived macrophage apoptosis. Lipids 2009; 45:29-36. [PMID: 19946756 DOI: 10.1007/s11745-009-3375-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Accepted: 11/10/2009] [Indexed: 01/12/2023]
Abstract
Steroidogenic acute regulatory protein (StAR) plays an important role in the maintenance of intracellular lipid homeostasis. Macrophages are the key cellular player in the pathophysiology of atherosclerosis. Imbalance of macrophage lipid homeostasis causes cellular apoptosis, which is the key process in the initiation of atherosclerosis. The present study has investigated the effects of StAR in the apoptotic process of human THP-1 derived macrophages induced by serum withdrawal or Ox-LDL. Overexpression of StAR significantly decreased the number of apoptotic macrophages by decreasing the expression of pro-apoptotic genes Caspase-3 and Bax mRNA and protein levels, as well as through increasing expression of anti-apoptotic gene Bcl-2 mRNA and protein levels in the absence and presence of Ox-LDL. The results indicate that StAR plays an important role in macrophage and foam cell apoptotic processing, which may provide a potential method for preventing atherosclerosis.
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Affiliation(s)
- Qianming Bai
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, P.O. Box 224, 138 Yixueyuan Road, 200032 Shanghai, People's Republic of China
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Imen JS, Billiet L, Cuaz-Pérolin C, Michaud N, Rouis M. The regulated in development and DNA damage response 2 (REDD2) gene mediates human monocyte cell death through a reduction in thioredoxin-1 expression. Free Radic Biol Med 2009; 46:1404-10. [PMID: 19268525 DOI: 10.1016/j.freeradbiomed.2009.02.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Revised: 02/23/2009] [Accepted: 02/23/2009] [Indexed: 11/24/2022]
Abstract
In a previous study, we identified the regulated in development and DNA damage response 2 (REDD2) gene as a highly expressed gene in human atherosclerotic lesions in comparison to normal artery, as well as in cultured human macrophages, and showed its implication in oxidized low-density lipoprotein (LDL)-induced macrophage death sensitivity. In this article, we attempt to identify the mechanism by which REDD2 induces such a phenomenon. Transient transfection of U-937 monocytic cells with a pCI.CMV.REDD2 expression vector increased by approximately twofold the mRNA levels of REDD2 in comparison to control cells transfected with pCI.CMV.GFP. Reactive oxygen species (ROS) production was significantly induced in REDD2-transfected cells compared with control cells (157+/-48 and 100+/-8 arbitrary units/mg cell protein, respectively; p<0.05). Moreover, a significant increase in parameters known to reflect the oxidative modifications of LDL was observed. Among enzymes involved in ROS production or degradation, we found a specific reduction in thioredoxin-1 (Trx-1) mRNA ( approximately 52+/-7% decrease, p<0.01 vs control cells) and protein ( approximately 60+/-4% decrease, p<0.001 vs control cells) levels in cells overexpressing REDD2 in comparison to control cells. In contrast, transfection of U-937 cells with siRNA against REDD2 decreased the mRNA levels of REDD2 by approximately 60% and increased Trx-1 mRNA and protein levels. Moreover, we observed no or a moderate increase in Bax (proapoptotic) and a significant decrease in Bcl2 (antiapoptotic) gene expression in cells that overexpress REDD2 compared to control cells. In addition, we showed that Trx-1 mRNA and protein levels were increased at low H(2)O(2) doses and decreased at higher doses. Interestingly, macrophages isolated from human atherosclerotic lesions differentially express REDD2 and Trx-1. Indeed, in certain patients, levels of REDD2 mRNA were low and those of Trx-1 mRNA were high. In contrast, in other patients, levels of REDD2 were high and levels of Trx-1 mRNA were low.
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13
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Brodeur MR, Brissette L, Falstrault L, Moreau R. HDL3 reduces the association and modulates the metabolism of oxidized LDL by osteoblastic cells: a protection against cell death. J Cell Biochem 2009; 105:1374-85. [PMID: 18980242 DOI: 10.1002/jcb.21938] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Oxidized low density lipoproteins (OxLDL) are known to promote atherosclerosis, but it is only recently that OxLDL have been associated with alterations of the functions of bone-forming osteoblasts and osteoporosis. Although high density lipoproteins (HDL) are recognized for their anti-atherogenic action, there is less information about their ability to protect against osteoporosis. Therefore, we investigated the capacity of HDL3 to prevent the cell death induced by OxLDL in human osteoblastic cells. Simultaneous exposure of the cells to HDL3 and OxLDL abolished the reduction of cell viability monitored by MTT activity measurement and the induction of apoptosis determined by annexin V staining indicating that HDL3 prevent the apoptosis of osteoblasts induced by OxLDL. This protection correlated with the displacement by HDL3 of OxLDL association to osteoblasts, signifying that OxLDL binding and/or internalization are/is necessary for their cytotoxic effects. We also found that exposition of osteoblastic cells to HDL3 prior to incubation with OxLDL reduced cell death and preserved the lysosomal integrity. This protection was correlated with an increase of SR-BI expression, a modification of OxLDL metabolism with less global uptake of OxLDL and greater selective uptake of cholesterol from OxLDL. These results strongly suggest that, as for atherosclerosis, HDL may exert beneficial actions on bone metabolism.
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Affiliation(s)
- Mathieu R Brodeur
- Laboratoire du Métabolisme Osseux, Centre BioMed, Département des Sciences Biologiques, Université du Québec à Montréal, Montréal, Québec, Canada H3C 3P8
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Li W, Kornmark L, Jonasson L, Forssell C, Yuan XM. Cathepsin L is significantly associated with apoptosis and plaque destabilization in human atherosclerosis. Atherosclerosis 2009; 202:92-102. [DOI: 10.1016/j.atherosclerosis.2008.03.027] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Revised: 03/19/2008] [Accepted: 03/20/2008] [Indexed: 10/22/2022]
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15
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Relationship between oxidized LDL antibodies and different stages of esophageal carcinoma. Arch Med Res 2008; 39:760-7. [PMID: 18996289 DOI: 10.1016/j.arcmed.2008.08.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2008] [Accepted: 08/12/2008] [Indexed: 11/20/2022]
Abstract
BACKGROUND The aim of the study was to evaluate the association of antibodies against oxidized low-density lipoproteins (oxLDL-Ab) with esophageal carcinogenic progression. METHODS All 40- to 69-year-old residents from Feicheng were screened for esophageal lesions by endoscopic staining with 1.2% iodine solution combined with pathological evaluations. In this study there were 33 controls with normal esophageal squamous epithelium cells, 37 patients with basal cell hyperplasia, 47 with esophageal squamous cell dysplasia, and 43 with esophageal squamous cell carcinoma (ESCC). OxLDL-Ab was determined by ELISA. Total cholesterol (TC), high-density lipoproteins (HDL), triglycerides, serum albumin and blood pressure were co-estimated. Analysis of covariance (ANCOVA) was used when comparing oxLDL-Ab among the four groups to control the influence of covariates. Cumulative logistic model was applied to study the influencing factors for the multistage development of esophageal carcinoma. RESULTS The level of oxLDL-Ab decreased gradually along with the different stages of esophageal carcinogenic progression, with the ESCC group being the lowest after controlling for possible covariates. Cumulative logistic model showed that oxLDL-Ab had a negative correlation with the development of esophageal carcinoma. LDL, HDL, and TC were also decreased in patients with ESCC. CONCLUSIONS Antibodies against oxLDL were decreased in patients with esophageal carcinoma. Although the unambiguous role of oxLDL-Ab needs further studies to elucidate, the results may give us some insight in the research of etiological factors for esophagael cancer in the future.
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16
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Pócsi I, Jeney V, Kertai P, Pócsi I, Emri T, Gyémánt G, Fésüs L, Balla J, Balla G. Fungal siderophores function as protective agents of LDL oxidation and are promising anti-atherosclerotic metabolites in functional food. Mol Nutr Food Res 2008; 52:1434-47. [DOI: 10.1002/mnfr.200700467] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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17
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Abstract
Mitochondrial outer membrane permeabilization (MOMP) constitutes one of the major checkpoint(s) of apoptotic and necrotic cell death. Recently, the permeabilization of yet another organelle, the lysosome, has been shown to initiate a cell death pathway, in specific circumstances. Lysosomal membrane permeabilization (LMP) causes the release of cathepsins and other hydrolases from the lysosomal lumen to the cytosol. LMP is induced by a plethora of distinct stimuli including reactive oxygen species, lysosomotropic compounds with detergent activity, as well as some endogenous cell death effectors such as Bax. LMP is a potentially lethal event because the ectopic presence of lysosomal proteases in the cytosol causes digestion of vital proteins and the activation of additional hydrolases including caspases. This latter process is usually mediated indirectly, through a cascade in which LMP causes the proteolytic activation of Bid (which is cleaved by the two lysosomal cathepsins B and D), which then induces MOMP, resulting in cytochrome c release and apoptosome-dependent caspase activation. However, massive LMP often results in cell death without caspase activation; this cell death may adopt a subapoptotic or necrotic appearance. The regulation of LMP is perturbed in cancer cells, suggesting that specific strategies for LMP induction might lead to novel therapeutic avenues.
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Affiliation(s)
- P Boya
- 3D Lab (Development, Differentiation and Degeneration), Department of Cellular and Molecular Physiopathology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain.
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18
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Benes P, Vetvicka V, Fusek M. Cathepsin D--many functions of one aspartic protease. Crit Rev Oncol Hematol 2008; 68:12-28. [PMID: 18396408 PMCID: PMC2635020 DOI: 10.1016/j.critrevonc.2008.02.008] [Citation(s) in RCA: 449] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Revised: 02/05/2008] [Accepted: 02/22/2008] [Indexed: 12/11/2022] Open
Abstract
For years, it has been held that cathepsin D (CD) is involved in rather non-specific protein degradation in a strongly acidic milieu of lysosomes. Studies with CD knock-out mice revealed that CD is not necessary for embryonal development, but it is indispensable for postnatal tissue homeostasis. Mutation that abolishes CD enzymatic activity causes neuronal ceroid lipofuscinosis (NCL) characterized by severe neurodegeneration, developmental regression, visual loss and epilepsy in both animals and humans. In the last decade, however, an increasing number of studies demonstrated that enzymatic function of CD is not restricted solely to acidic milieu of lysosomes with important consequences in regulation of apoptosis. In addition to CD enzymatic activity, it has been shown that apoptosis is also regulated by catalytically inactive mutants of CD which suggests that CD interacts with other important molecules and influences cell signaling. Moreover, procathepsin D (pCD), secreted from cancer cells, acts as a mitogen on both cancer and stromal cells and stimulates their pro-invasive and pro-metastatic properties. Numerous studies found that pCD/CD level represents an independent prognostic factor in a variety of cancers and is therefore considered to be a potential target of anti-cancer therapy. Studies dealing with functions of cathepsin D are complicated by the fact that there are several simultaneous forms of CD in a cell-pCD, intermediate enzymatically active CD and mature heavy and light chain CD. It became evident that these forms may differently regulate the above-mentioned processes. In this article, we review the possible functions of CD and its various forms in cells and organisms during physiological and pathological conditions.
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Affiliation(s)
- Petr Benes
- Laboratory of Cell Differentiation, Department of Experimental Biology, Faculty of Science, Masaryk University, ILBIT A3, Kamenice 3, Brno 625 00, Czech Republic.
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19
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Farkas E, Bátka D, Kremper G, Pócsi I. Structure-based differences between the metal ion selectivity of two siderophores desferrioxamine B (DFB) and desferricoprogen (DFC): Why DFC is much better Pb(II) sequestering agent than DFB? J Inorg Biochem 2008; 102:1654-9. [DOI: 10.1016/j.jinorgbio.2008.03.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Accepted: 03/21/2008] [Indexed: 11/16/2022]
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20
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Hamel P, Abed E, Brissette L, Moreau R. Characterization of oxidized low-density lipoprotein-induced hormesis-like effects in osteoblastic cells. Am J Physiol Cell Physiol 2008; 294:C1021-33. [PMID: 18287334 DOI: 10.1152/ajpcell.00361.2007] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Epidemiological studies indicate that patients suffering from atherosclerosis are predisposed to develop osteoporosis. Atherogenic determinants such as oxidized low-density lipoprotein (oxLDL) particles have been shown both to stimulate the proliferation and promote apoptosis of bone-forming osteoblasts. Given such opposite responses, we characterized the oxLDL-induced hormesis-like effects in osteoblasts. Biphasic 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reductive activity responses were induced by oxLDL where low concentrations (10-50 microg/ml) increased and high concentrations (from 150 microg/ml) reduced the MTT activity. Cell proliferation stimulation by oxLDL partially accounted for the increased MTT activity. No alteration of mitochondria mass was noticed, whereas low concentrations of oxLDL induced mitochondria hyperpolarization and increased the cellular levels of reactive oxygen species (ROS). The oxLDL-induced MTT activity was not related to intracellular ROS levels. OxLDL increased NAD(P)H-associated cellular fluorescence and flavoenzyme inhibitor diphenyleneiodonium reduced basal and oxLDL-induced MTT activity, suggesting an enhancement of NAD(P)H-dependent cellular reduction potential. Low concentrations of oxLDL reduced cellular thiol content and increased metallothionein expression, suggesting the induction of compensatory mechanisms for the maintenance of cell redox state. These concentrations of oxLDL reduced osteoblast alkaline phosphatase activity and cell migration. Our results indicate that oxLDL particles cause hormesis-like response with the stimulation of both proliferation and cellular NAD(P)H-dependent reduction potential by low concentrations, whereas high concentrations lead to reduction of MTT activity associated with the cell death. Given the effects of low concentrations of oxLDL on osteoblast functions, oxLDL may contribute to the impairment of bone remodeling equilibrium.
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Affiliation(s)
- P Hamel
- Département des Sciences Biologiques, Université du Québec à Montréal, Montréal, Québec, Canada
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21
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Li W, Ostblom M, Xu LH, Hellsten A, Leanderson P, Liedberg B, Brunk UT, Eaton JW, Yuan XM. Cytocidal effects of atheromatous plaque components: the death zone revisited. FASEB J 2006; 20:2281-90. [PMID: 17077305 DOI: 10.1096/fj.06-6114com] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Earlier we suggested that atheroma lesions constitute a "death zone" containing toxic materials that may cause dysfunction and demise of invading macrophages to prevent the removal of plaque materials. Here we have assessed the cytotoxic effects of nonfractionated gruel and insoluble (ceroid-like) material derived from advanced human atheroma. METHODS AND RESULTS The insoluble material within advanced atherosclerotic plaque was isolated following protease K digestion and extensive extraction with aqueous and organic solvents. FTIR, Raman, and atomic absorption spectroscopy suggested that, despite its fluorescent nature, this material closely resembled hydroxyapatite and dentin, but also contained a significant amount of iron and calcium. When added to J774 cells and human macrophages in culture, this insoluble substance was phagocytosed, and progressive cell death followed. However, an even more cytotoxic activity was found in the atheromatous "gruel" that contains abundant carbonyls/aldehydes. Cell death caused by both crude gruel and ceroid could be blocked by preincubating cells with the lipophilic iron chelator salicylaldehyde isonicotinoyl hydrazone, apoferritin, BAPTA/AM, or sodium borohydride, indicating that cellular iron, calcium, and reactive aldehyde(s) are responsible for the observed cytotoxicity. CONCLUSIONS Toxic materials within atheromatous lesions include both ceroid and even more cytotoxic lipidaceous materials. The cytotoxic effects of these plaque components may help explain the persistence of atherosclerotic lesions.
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Affiliation(s)
- Wei Li
- Division of Experimental Pathology, Faculty of Health Sciences, Linköping University, SE-581 85 Linköping, Sweden
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22
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Ou HC, Chou FP, Lin TM, Yang CH, Sheu WHH. Protective effects of eugenol against oxidized LDL-induced cytotoxicity and adhesion molecule expression in endothelial cells. Food Chem Toxicol 2006; 44:1485-95. [PMID: 16762475 DOI: 10.1016/j.fct.2006.04.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Revised: 04/20/2006] [Accepted: 04/20/2006] [Indexed: 11/25/2022]
Abstract
Eugenol, a natural constituent of a number of aromatic plants and their essential oil fractions, has several biological effects. However, its protective effects against endothelial injury remain unclarified. This study investigates how eugenol affects human umbilical vein endothelial cells (HUVECs) dysfunction mediated by oxidized low density lipoprotein (oxLDL). Our results showed that the suppression of endothelial NO synthase (eNOS) expression, enhancement of adhesion molecules (ICAM, VCAM, and E-selectin) expression, and adherence of monocytic THP1 cells caused by a non-cytotoxic concentration (100 microg/ml) of oxLDL were ameliorated following a eugenol treatment (12.5-100 microM) in HUVECs. Eugneol also inhibited the reactive oxygen species (ROS) generation, intracellular calcium accumulation, and the subsequent mitochondrial membrane potential collapse, cytochrome c release and caspase-3 activation induced by oxLDL. The cytotoxicity and apoptotic features induced by a cytotoxic concentration (200 microg/ml) of oxLDL was also attenuated by eugenol. Our results suggest that eugenol may protect against the oxLDL-induced dysfunction in endothelial cells.
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Affiliation(s)
- Hsiu-Chung Ou
- Division of Endocrinology and Metabolism, Department of Education and Medical Research, Taichung Veterans General Hospital, Institute of Biochemistry, Chung Shan Medical University, Taichung, Taiwan
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23
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Li W, Hellsten A, Xu LH, Zhuang DM, Jansson K, Brunk UT, Yuan XM. Foam cell death induced by 7beta-hydroxycholesterol is mediated by labile iron-driven oxidative injury: mechanisms underlying induction of ferritin in human atheroma. Free Radic Biol Med 2005; 39:864-75. [PMID: 16140207 DOI: 10.1016/j.freeradbiomed.2005.05.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2005] [Revised: 04/08/2005] [Accepted: 05/04/2005] [Indexed: 10/25/2022]
Abstract
Human atherosclerotic lesions typically contain large amounts of ferritin associated with apoptotic macrophages and foam cells, although the reasons are unknown. In the present investigation, we studied the relationship between ferritin induction and occurrence of apoptosis in 7beta-hydroxycholesterol (7beta-OH)-treated monocytic cells and macrophages. We found that 7beta-OH enlarges the intracellular labile iron pool, increases formation of reactive oxygen species (ROS), and induces ferritin and cytosolic accumulation of lipid droplets, lysosomal destabilization, and apoptototic macrophage death. Since ferritin is a phase II-type protective protein, our findings suggest that ferritin upregulation here worked as an inefficient defense mechanism. Addition to the culture medium of both a membrane-permeable iron chelator 10-phenanthroline and the non-membrane-permeable iron chelators apoferritin and desferrioxamine afforded significant protection against the 7beta-OH-induced effects. Consequently, endocytosed iron compounds dramatically augmented 7beta-OH-induced cytotoxicity. We conclude that oxidized lipid 7beta-OH causes not only foam cell formation but also oxidative damage with abnormal metabolism of cellular iron. The findings suggest that modulation of iron metabolism in human atheroma may be a potential therapeutic strategy against atherosclerosis.
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Affiliation(s)
- Wei Li
- Division of Experimental Pathology, Faculty of Health Sciences, Linköping University, Linköping SE-581 85, Sweden.
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24
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Yaraei K, Campbell LA, Zhu X, Liles WC, Kuo CC, Rosenfeld ME. Chlamydia pneumoniae augments the oxidized low-density lipoprotein-induced death of mouse macrophages by a caspase-independent pathway. Infect Immun 2005; 73:4315-22. [PMID: 15972525 PMCID: PMC1168605 DOI: 10.1128/iai.73.7.4315-4322.2005] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2004] [Revised: 02/03/2005] [Accepted: 02/28/2005] [Indexed: 11/20/2022] Open
Abstract
Chlamydia pneumoniae is a common respiratory pathogen that is associated with an increased risk of cardiovascular disease. However, the mechanisms by which C. pneumoniae contributes to cardiovascular disease have not been determined yet. C. pneumoniae infection may accelerate the death of cells within atherosclerotic lesions and contribute to the formation of unstable lesions. To test this hypothesis, the impact of C. pneumoniae infection on the death of lipid-loaded mouse macrophages was investigated. It was observed that RAW 264.7 cells are highly susceptible to the toxic effects of oxidized low-density lipoprotein (LDL) and exhibit markers of cell death within 24 h of treatment with as little as 5 microg/ml oxidized LDL. Subsequent infection with either live C. pneumoniae or heat-killed or UV-inactivated C. pneumoniae at a low multiplicity of infection for 24 to 72 h stimulated both additional binding of annexin V and the uptake of propidium iodide. Thus, C. pneumoniae augments the effects of oxidized LDL on cell death independent of a sustained infection. However, unlike oxidized LDL, C. pneumoniae infection does not activate caspase 3 or induce formation of the mitochondrial transition pore or the fragmentation of DNA, all of which are classical markers of apoptosis. Furthermore, primary bone marrow macrophages isolated from mice deficient in Toll-like receptor 2 (TLR-2) but not TLR-4 are resistant to C. pneumoniae-induced death. These data suggest that C. pneumoniae kills cells by a caspase-independent pathway and that the process is potentially mediated by activation of TLR-2.
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Affiliation(s)
- Kambiz Yaraei
- Department of Pathobiology, Box 353410, University of Washington, Seattle, Washington 98195, USA
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25
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Willis MS, Klassen LW, Carlson DL, Brouse CF, Thiele GM. Malondialdehyde-acetaldehyde haptenated protein binds macrophage scavenger receptor(s) and induces lysosomal damage. Int Immunopharmacol 2005; 4:885-99. [PMID: 15182728 DOI: 10.1016/j.intimp.2004.04.004] [Citation(s) in RCA: 211] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2004] [Revised: 03/16/2004] [Accepted: 04/02/2004] [Indexed: 11/24/2022]
Abstract
There is evidence that the chemical modification of proteins (haptens) with malondialdehyde-acetaldehyde (MAA) and the immune response to these haptenated proteins is associated with the initiation and/or progression of alcohol liver disease. Experimentally, proteins modified with MAA induce antibody and T cell responses, which are mediated by scavenger receptor(s). Moreover, macrophages have been shown to play an important role in processing and presenting MAA-haptenated proteins in vitro. In vitro, MAA-modified proteins have been shown to induce both apoptosis and necrosis in a dose- and cell-type-dependent manner. Natural ligands modified by oxidative stress, such as oxidized LDL, similarly initiate not only antibody responses, but also cause cell death by disrupting lysosomes after binding to scavenger receptors and internalization. We therefore investigated the binding, internalization, and lysosomal integrity in a macrophage cell line to a MAA-haptenated protein. We demonstrate for the first time that MAA-haptenated proteins are preferentially bound by scavenger receptors on macrophages, which internalize the ligands and shuttle them to lysosomes. Moreover, MAA-haptenated proteins are demonstrated to be associated with a rapid dose-dependent disruption in lysosomal integrity, resulting in leakage and caspase activation. Similarly, as hen egg lysozyme (HEL)-MAA concentrations increased (>31.3 microg/ml), increased levels of apoptosis and a G1/S cell cycle checkpoint inhibition were identified. This study identifies mechanisms by which MAA-haptenated proteins are taken up by a representative antigen-presenting cell and may delineate steps by which MAA-haptenated proteins induce cell death and induce their immunogenicity to the carrier protein.
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Affiliation(s)
- Monte S Willis
- Department of Internal Medicine, University of Nebraska Medical Center, 983025 Nebraska Medical Center, Omaha, NE 68198-3025, USA.
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26
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Suzuki K, Ito Y, Wakai K, Kawado M, Hashimoto S, Toyoshima H, Kojima M, Tokudome S, Hayakawa N, Watanabe Y, Tamakoshi K, Suzuki S, Ozasa K, Tamakoshi A. Serum Oxidized Low-Density Lipoprotein Levels and Risk of Colorectal Cancer: A Case-Control Study Nested in the Japan Collaborative Cohort Study. Cancer Epidemiol Biomarkers Prev 2004. [DOI: 10.1158/1055-9965.1781.13.11] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Abstract
Oxidative stress plays an important role in carcinogenesis, but few epidemiologic studies have examined associations with risk of colorectal cancer. Relationships between serum levels of oxidized low-density lipoprotein (oxLDL) and oxLDL antibody (oLAB) and colorectal cancer risk were investigated in a case-control study nested in the Japan Collaborative Cohort Study for Evaluation of Cancer Risk. Serum samples and lifestyle information were collected at baseline from 39,242 men and women between 1988 and 1990. Of these, 161 incidents and deaths from colorectal cancer were identified through 1999, and 395 controls were matched for gender, age, and study area. Measurements were taken of serum oxLDL levels in 119 cases and 316 controls and serum oLAB levels in 153 cases and 376 controls. Odds ratios (95% confidence intervals) across quartiles, adjusted for confounding factors, were 1.55 (0.70-3.46), 1.90 (0.84-4.28), and 3.65 (1.50-8.92) for oxLDL (Ptrend = 0.004) and 0.98 (0.54-1.80), 0.75 (0.39-1.48), and 1.68 (0.90-3.13) for oLAB (Ptrend = 0.140). Further adjustment for serum total cholesterol and α-tocopherol did not materially change these associations. Odds ratio (95% confidence interval) of the highest quartile of serum oxLDL compared with the lowest quartile was 3.40 (1.09-10.58; Ptrend = 0.045). Analyses restricted to colon cancer cases and corresponding controls yielded similar relationships between serum oxLDL and oLAB levels and risk. In conclusion, higher levels of serum oxLDL may increase risk of colorectal cancer.
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Affiliation(s)
- Koji Suzuki
- 1Department of Public Health, Fujita Health University School of Health Sciences
| | - Yoshinori Ito
- 1Department of Public Health, Fujita Health University School of Health Sciences
| | - Kenji Wakai
- 3Division of Epidemiology and Prevention, Aichi Cancer Center Research Institute; Departments of
- 4Preventive Medicine/Biostatistics and Medical Decision Making and
| | - Miyuki Kawado
- 2Department of Hygiene, Fujita Health University School of Medicine, Toyoake, Japan
| | - Shuji Hashimoto
- 2Department of Hygiene, Fujita Health University School of Medicine, Toyoake, Japan
| | - Hideaki Toyoshima
- 5Public Health/Health Information Dynamics, Nagoya University Graduate School of Medicine
| | - Masayo Kojima
- 6Department of Health Promotion and Preventive Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Shinkan Tokudome
- 6Department of Health Promotion and Preventive Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Norihiko Hayakawa
- 7Department of Epidemiology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan; and
| | - Yoshiyuki Watanabe
- 8Department of Epidemiology for Community Health and Medicine, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan
| | - Koji Tamakoshi
- 5Public Health/Health Information Dynamics, Nagoya University Graduate School of Medicine
| | - Sadao Suzuki
- 6Department of Health Promotion and Preventive Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Kotaro Ozasa
- 8Department of Epidemiology for Community Health and Medicine, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan
| | - Akiko Tamakoshi
- 4Preventive Medicine/Biostatistics and Medical Decision Making and
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27
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Cuaz-Pérolin C, Furman C, Larigauderie G, Legedz L, Lasselin C, Copin C, Jaye M, Searfoss G, Yu KT, Duverger N, Nègre-Salvayre A, Fruchart JC, Rouis M. REDD2 gene is upregulated by modified LDL or hypoxia and mediates human macrophage cell death. Arterioscler Thromb Vasc Biol 2004; 24:1830-5. [PMID: 15308555 DOI: 10.1161/01.atv.0000142366.69080.c3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE Cholesterol accumulation in macrophages is known to alter macrophage biology. In this article we studied the impact of macrophage cholesterol loading on gene expression and identified a novel gene implicated in cell death. METHODS AND RESULTS The regulated in development and DNA damage response 2 (REDD2) gene was strongly upregulated as THP-1 macrophages are converted to foam cells. These results were confirmed by Northern blot of RNA from human monocyte-derived macrophages (HMDM) treated with oxidized LDL (oxLDL). Human REDD2 shares 86% amino acid sequence identity with murine RTP801-like protein, which is 33% identical to RTP801, a hypoxia-inducible factor 1-responsive gene involved in apoptosis. Treatment of HMDM with desferrioxamine, a molecule that mimics the effect of hypoxia, increased expression of REDD2 in a concentration-dependent fashion. Transfection of U-937 and HMEC cells with a REDD2 expression vector increased the sensitivity of the cells for oxLDL-induced cytotoxicity, by inducing a shift from apoptosis toward necrosis. In contrast, suppression of mRNA expression using siRNA approach resulted in increased resistance to oxLDL treatment. CONCLUSIONS We showed that stimulation of REDD2 expression in macrophages increases oxLDL-induced cell death, suggesting that REDD2 gene might play an important role in arterial pathology.
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Affiliation(s)
- C Cuaz-Pérolin
- INSERM U-545, and Institut Pasteur de Lille, Lille, France
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28
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Furman C, Rundlöf AK, Larigauderie G, Jaye M, Bricca G, Copin C, Kandoussi AM, Fruchart JC, Arnér ESJ, Rouis M. Thioredoxin reductase 1 is upregulated in atherosclerotic plaques: specific induction of the promoter in human macrophages by oxidized low-density lipoproteins. Free Radic Biol Med 2004; 37:71-85. [PMID: 15183196 DOI: 10.1016/j.freeradbiomed.2004.04.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2003] [Revised: 03/01/2004] [Accepted: 04/16/2004] [Indexed: 12/17/2022]
Abstract
Uptake of modified low-density lipoproteins (LDLs) by macrophages in the arterial wall is an important event in atherogenesis. Indeed, oxidatively modified LDLs (oxLDLs) are known to affect various cellular processes by modulating oxidation-sensitive signaling pathways. Here we found that the ubiquitous 55 kDa selenoprotein thioredoxin reductase 1 (TrxR1), which is a key enzyme for cellular redox control and antioxidant defense, was upregulated in human atherosclerotic plaques and expressed in foam cells. Using reverse transcription polymerase chain reaction analysis, we also found that oxLDLs, but not native LDLs (nLDLs), dose-dependently increased TrxR1 mRNA in human monocyte-derived macrophages (HMDMs). This stimulating effect was specific for oxLDLs, as pro-inflammatory factors, such as lipopolysaccharides (LPSs), interleukin-1beta (IL-1beta), interleukin-6 (Il-6), and tumor necrosis factor alpha (TNFalpha), under the same conditions, failed to induce TrxR1 mRNA levels to the same extent. Moreover, phorbol ester-differentiated THP-1 cells or HMDMs transiently transfected with TrxR1 promoter fragments linked to a luciferase reporter gene allowed identification of a defined promoter region as specifically responding to the phospholipid component of oxLDLs (p <.05 vs. phospholipid component of nLDLs). Gel mobility shift analyses identified a short 40-nucleotide stretch of the promoter carrying AP-1 and HoxA5 consensus motifs that responded with an altered shift pattern in THP-1 cells treated with oxLDLs, however, without evident involvement of either the Fos, Jun, Nrf2 or HoxA5 transcription factors.
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Affiliation(s)
- C Furman
- INSERM U-545, and Institut Pasteur de Lille, 59019 Lille, France
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29
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Abstract
This review focuses on the role of monocytes in the early phase of atherogenesis, before foam cell formation. An emerging consensus underscores the importance of the cellular inflammatory system in atherogenesis. Initiation of the process apparently hinges on accumulating low-density lipoproteins (LDL) undergoing oxidation and glycation, providing stimuli for the release of monocyte attracting chemokines and for the upregulation of endothelial adhesive molecules. These conditions favor monocyte transmigration to the intima, where chemically modified, aggregated, or proteoglycan- or antibody-complexed LDL may be endocytotically internalized via scavenger receptors present on the emergent macrophage surface. The differentiating monocytes in concert with T lymphocytes exert a modulating effect on lipoproteins. These events propagate a series of reactions entailing generation of lipid peroxides and expression of chemokines, adhesion molecules, cytokines, and growth factors, thereby sustaining an ongoing inflammatory process leading ultimately to lesion formation. New data emerging from studies using transgenic animals, notably mice, have provided novel insights into many of the cellular interactions and signaling mechanisms involving monocytes/macrophages in the atherogenic processes. A number of these studies, focusing on mechanisms for monocyte activation and the roles of adhesive molecules, chemokines, cytokines and growth factors, are addressed in this review.
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Affiliation(s)
- Bjarne Osterud
- Department of Biochemistry, Institute of Medical Biology, Faculty of Medicine, University of Tromsø, Tromsø, Norway.
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30
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de Nigris F, Lerman A, Ignarro LJ, Williams-Ignarro S, Sica V, Baker AH, Lerman LO, Geng YJ, Napoli C. Oxidation-sensitive mechanisms, vascular apoptosis and atherosclerosis. Trends Mol Med 2003; 9:351-9. [PMID: 12928037 DOI: 10.1016/s1471-4914(03)00139-4] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Increased generation of oxidants, resulting from disruption of aerobic metabolism and from respiratory burst, is an essential defense mechanism against pathogens and aberrant cells. However, oxidative stress can also trigger and enhance deregulated apoptosis or programmed cell death, characteristic of atherosclerotic lesions. Oxidation-sensitive mechanisms also modulate cellular signaling pathways that regulate vascular expression of cytokines and growth factors, and influence atherogenesis, in particular when increased levels of plasma lipoproteins provide ample substrate for lipid peroxidation and lead to increased formation of adducts with lipoprotein amino acids. In some cases, increased oxidation and apoptosis in a group of cells might be beneficial for survival and function of other groups of arterial cells. However, overall, oxidation and apoptosis appear to promote the progression of diseased arteries towards a lesion that is vulnerable to rupture, and to give rise to myocardial infarction and ischemic stroke. Recent rapid advances in our understanding of the interactions between oxidative stress, apoptosis and arterial gene regulation suggest that selective interventions targeting these biological functions have great therapeutic potential.
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Affiliation(s)
- Filomena de Nigris
- Department of Pharmacological Sciences, University of Salerno, 84084 Salerno, Italy
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31
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Ditaranto-Desimone K, Saito M, Tekirian TL, Saito M, Berg M, Dubowchik G, Soreghan B, Thomas S, Marks N, Yang AJ. Neuronal endosomal/lysosomal membrane destabilization activates caspases and induces abnormal accumulation of the lipid secondary messenger ceramide. Brain Res Bull 2003; 59:523-31. [PMID: 12576150 DOI: 10.1016/s0361-9230(02)00948-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Impairment of endosomal/lysosomal functions are reported as some of the earliest changes in several age-related neurological disorders such as Alzheimer's disease. Dysregulation of the lysosomal system is also accompanied by the accumulation of age-associated pigments and several recent reports have indicated that this age-related lipofuscin accumulation can sensitize cells to oxidative stress and apoptotic cell death. In this study, we have established and evaluated an in vitro age-related pathology paradigm that models lipofuscin accumulation. Our model consists of the treatment of cultured primary mouse neurons with lysosomotropic detergents. We have observed that one of the earliest biochemical changes associated with lysosomotropic detergent-induced membrane instability is a loss of the endosomal/lysosomal proton gradient integrity, followed by an activation of sphingomyelin hydrolysis and ceramide accumulation within enlarged endosomal/lysosomal vesicles. In addition, we demonstrate that ceramide accumulation correlates with the activation of proximal procaspases-8 and -9 as well as distal caspase-3, prior to the appearance of cell death. Taken together, we propose that disturbances of the endosomal/lysosomal system, in addition to the activation of the sphingomyelinase hydrolysis cycle, play essential roles in the course of post-mitotic neuronal aging. The abnormal accumulation of undigested lipids and proteins within dysfunctional endosomal/lysosomal vesicle populations during the process of pathological aging may serve as triggers of the cell death programs that are associated with downstream neurodegeneration.
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32
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Salvayre R, Auge N, Benoist H, Negre-Salvayre A. Oxidized low-density lipoprotein-induced apoptosis. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1585:213-21. [PMID: 12531556 DOI: 10.1016/s1388-1981(02)00343-8] [Citation(s) in RCA: 256] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Cultured cells are able to oxidize low-density lipoproteins (LDL) and oxidized LDL (oxLDL), which are present in atherosclerosis areas, exhibit a variety of biological properties potentially involved in atherogenesis. This review is focused on the toxicity of oxLDL, more precisely on the toxic compounds generated during LDL oxidation, the features and the mechanisms of cell death (apoptosis or necrosis) induced by oxLDL. After internalization, toxic oxidized lipids, namely lipid peroxides, oxysterols and aldehydes, induce modifications of cell proteins, elicit oxidative stress, lipid peroxidation and alter various signaling pathways and gene expression. These events may participate in the toxic effect, and converge to trigger an intense, delayed and sustained calcium peak which elicits either apoptosis or necrosis processes. OxLDL-induced apoptosis involves both mitochondrial and death-receptor (Fas/FasL) apoptotic pathways, thereby activating the classical caspase cascade and subsequent biochemical and morphological apoptotic features. When apoptosis is blocked by overexpression of Bcl-2, oxLDL trigger necrosis through a calcium-dependent pathway. Apoptosis occurring in atherosclerotic areas is potentially involved in endothelial cell lining defects, necrotic core formation and plaque rupture or erosion which may trigger atherothrombotic events. However, the precise role of oxLDL in apoptosis/necrosis occurring in vivo in atherosclerotic plaques remains to be clarified.
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Affiliation(s)
- Robert Salvayre
- INSERM U-466, Faculty of Medicine, University Paul Sabatier, CHU Rangueil, Avenue Jean Poulhès, 31054 Toulouse cedex 04, France.
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33
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Choi DH, Kim DH, Park YG, Chun BG, Choi SH. Protective effects of rilmenidine and AGN 192403 on oxidative cytotoxicity and mitochondrial inhibitor-induced cytotoxicity in astrocytes. Free Radic Biol Med 2002; 33:1321-33. [PMID: 12419464 DOI: 10.1016/s0891-5849(02)01041-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Oxidative stress and mitochondrial dysfunction are important aspects of pathogenesis, particularly in the brain, which is highly dependent on oxygen, and the protection of astrocytes is essential for neuroprotection. In this context, imidazoline drugs have been reported to be neuroprotective. Our recent study showed that imidazoline drugs, including guanabenz, inhibit the naphthazarin-induced oxidative cytotoxicity associated with lysosomal destabilization. We now report on a study into the protective effects of rilmenidine and AGN 192403, which have affinity for imidazoline-1 receptors, on the cytotoxicity induced by naphthazarin and inhibitors of mitochondrial respiration in astrocytes. Cytotoxicity was measured grossly by LDH release and by measuring changes in lysosomal membrane stability and features of mitochondrial membrane permeabilization. Naphthazarin-induced cytotoxicity was evidenced by the ordered development of lysosomal acridine orange relocation, decrease in mitochondrial potential, cytochrome c release, and caspase-9 activation, and was inhibited by guanabenz, rilmenidine, and AGN 192403. Antimycin A and rotenone induced mitochondrial dysfunction primarily, and their cytotoxicities were inhibited only by AGN 192403. Rilmenidine and guanabenz may have a lysosomal stabilizing effect, which underlies their protective effects. AGN 192403 might affect the mitochondrial cell death cascades, and had a novel protective effect on the cytotoxicity associated with mitochondrial dysfunction.
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Affiliation(s)
- Dong-Hee Choi
- Department of Pharmacology, Korea University College of Medicine, Seoul, South Korea
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34
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Madsen M, Graversen JH, Moestrup SK. Haptoglobin and CD163: captor and receptor gating hemoglobin to macrophage lysosomes. Redox Rep 2002; 6:386-8. [PMID: 11865982 DOI: 10.1179/135100001101536490] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The plasma protein haptoglobin and the endocytic hemoglobin receptor HbSR/CD163 are key molecules in the process of removing hemoglobin released from ruptured erythrocytes. Hemoglobin in plasma is instantly bound with high affinity to haptoglobin--an interaction leading to the recognition of the complex by HbSR/CD163 and endocytosis in macrophages. The haptoglobin-dependent HbSR/CD163 scavenging system for hemoglobin clearance prevents toxic effects of hemoglobin in plasma and kidney and explains the decrease in the haptoglobin plasma concentration in patients with accelerated hemolysis. The HbSR/CD163 activity may be of quantitative importance for iron uptake in macrophages in general and for some iron-associated pathological processes, e.g. the atherogenesis-promoting oxidation of LDL leading to foam cell formation and apoptosis in the vessel wall.
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Affiliation(s)
- M Madsen
- Department of Medical Biochemistry, University of Aarhus, Denmark
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35
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Affiliation(s)
- Hervé Benoist
- Inserm U466, Institut Louis Bugnard, CHU Rangueil, 31403 Toulouse, France
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36
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Turk B, Stoka V, Rozman-Pungercar J, Cirman T, Droga-Mazovec G, Oresić K, Turk V. Apoptotic pathways: involvement of lysosomal proteases. Biol Chem 2002; 383:1035-44. [PMID: 12437086 DOI: 10.1515/bc.2002.112] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Apoptosis or programmed cell death is the major mechanism used by multicellular organisms to remove infected, excessive and potentially dangerous cells. Cysteine proteases from the caspase family play a crucial role in the process. However, there is increasing evidence that lysosomal proteases are also involved in apoptosis. In this review various lysosomal proteases and their potential contribution to propagation of apoptosis are discussed.
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Affiliation(s)
- Boris Turk
- Department of Biochemistry and Molecular Biology, Jozef Stefan Institute, Ljubljana, Slovenia
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37
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Choi SH, Choi DH, Lee JJ, Park MS, Chun BG. Imidazoline drugs stabilize lysosomes and inhibit oxidative cytotoxicity in astrocytes. Free Radic Biol Med 2002; 32:394-405. [PMID: 11864779 DOI: 10.1016/s0891-5849(01)00819-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Oxidative stress is a primary pathogenesis in the brain, which is particularly vulnerable to oxidative stress. Maintenance of astrocyte functions under oxidative stress is essential to prevent neuronal injuries and to recover neuronal functions in various pathologic conditions. Imidazoline drugs have affinities for imidazoline receptors, which are highly distributed in the brain, and have been shown to be neuroprotective. This study presented the protective effects of several imidazoline drugs against oxidative cytotoxicity, in primary cultures of astrocytes. Imidazoline drugs, such as idazoxan, guanabenz, guanfacine, BU224, and RS-45041-190, showed protective effects against naphthazarin-induced oxidative cytotoxicity, as evidenced by LDH release and Hoechst 33342/propidium iodide staining. The imidazoline drugs stabilized lysosomes and inhibited naphthazarin-induced lysosomal destabilization, as evidenced by acridine orange relocation. Guanabenz inhibited, the leakage of lysosomal cathepsin D to cytosol, the decreased mitochondrial potential, and the release of mitochondrial cytochrome c, which were induced by naphthazarin. The lysosomal destabilization by oxidative stress and other apoptotic signals and subsequent cathepsin D leakage to the cytosol can induce apoptotic changes of mitochondria and eventually cell death. Therefore, lysosomal stabilization by imidazoline drugs may be ascribed to their protective effects against oxidative cytotoxicity.
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Affiliation(s)
- Sang-Hyun Choi
- Department of Pharmacology, Korea University College of Medicine, Seoul, South Korea.
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38
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Ferrari M, Werner GS, Rieber J, Richartz BM, Sigusch HH, Brandstädt A, Mudra H, Figulla HR. No influence of hemochromatosis-related gene mutations on restenosis rate in a retrospective study of 137 patients after coronary stent implantation. INTERNATIONAL JOURNAL OF CARDIOVASCULAR INTERVENTIONS 2001; 4:181-186. [PMID: 12036461 DOI: 10.1080/14628840127764] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND: Recent publications have shown an increased risk of coronary artery disease and myocardial infarction in patients with alteration of the hemochromatosis-related gene (HFE gene). The HFE gene mutation is associated with elevated iron uptake and serum iron overloading. Iron plays an important role in promoting the oxidation of LDL cholesterol. The iron deposition in the endothelium and in the media is closely associated with the progression of atherosclerosis. However, it is unclear whether the mutation of the HFE gene also influences the rate of restenosis after coronary stent implantation. METHODS: In a retrospective analysis, 137 patients (pts.) who underwent elective coronary stent implantation were angiographically reevaluated after six months. All patients were part of the OPTICUS-study population which investigated optimized stent implantation guided by intravascular ultrasound. Computerized quantitative analysis was performed in all procedures in a double-blinded fashion. At six-month follow-up, DNA fragments containing the substitution of tyrosine for cytosine at codon 282 were amplified by PCR. The results were analyzed by polyacrylamide gel electrophoresis. Statistical analysis was performed by multivariate linear regression. RESULTS: According to the HFE gene polymorphism we formed two subgroups: 129 pts. (94%) did not show changes in HFE gene (NH), 8 pts. (6%) were heterozygous for HFE Cys282Tyr (H). The groups did not differ in age, gender, extent of coronary artery disease, initial degree and length of stenosis and all patients underwent re-angiography. At six-month follow-up the average luminal narrowing in the stented vessel was 36.2 +/- 20.3% in the NH group compared with 27.8 +/- 20.0% in the H group which was statistically not significant (n. s.). The minimal luminal diameter was 1.9 +/- 0.71 mm in the NH group and 2.2 +/- 0.66 mm in the H group respectively (n. s.). 33 pts (26%) in the NH group versus 2 pts (25%) in the H group had >/= 50% diameter narrowing at follow-up (n. s.). The odds ratio of stent restenosis in H patients was 0.932. CONCLUSIONS: The authors did not find any association between restenosis rate and HFE gene alteration and therefore, we conclude that the polymorphism of the HFE gene is not a risk factor for restenosis after coronary stent implantation.
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Affiliation(s)
- Markus Ferrari
- Clinic of Internal Medicine, Friedrich-Schiller University, Jena, Germany
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39
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Bursch W. The autophagosomal-lysosomal compartment in programmed cell death. Cell Death Differ 2001; 8:569-81. [PMID: 11536007 DOI: 10.1038/sj.cdd.4400852] [Citation(s) in RCA: 453] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2000] [Revised: 01/19/2001] [Accepted: 02/01/2001] [Indexed: 12/14/2022] Open
Abstract
In the last decade a tremendous progress has been achieved in understanding the control of apoptosis by survival and death factors as well as the molecular mechanisms of preparation and execution of the cell's suicide. However, accumulating evidence suggests that programmed cell death (PCD) is not confined to apoptosis but that cells use different pathways for active self-destruction as reflected by different morphology: condensation prominent, type I or apoptosis; autophagy prominent, type II; etc. Autophagic PCD appears to be a phylogenetically old phenomenon, it may occur in physiological and disease states. Recently, distinct biochemical and molecular features have been be assigned to this type of PCD. However, autophagic and apoptotic PCD should not be considered as mutually exclusive phenomena. Rather, they appear to reflect a high degree of flexibility in a cell's response to changes of environmental conditions, both physiological or pathological. Furthermore, recent data suggest that diverse or relatively unspecific signals such as photodamage or lysosomotropic agents may be mediated by lysosomal cysteine proteases (cathepsins) to caspases and thus, apoptosis. The present paper reviews morphological, functional and biochemical/molecular data suggesting the participation of the autophagosomal-lysosomal compartment in programmed cell death.
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Affiliation(s)
- W Bursch
- Institut für Krebsforschung der Universität Wien, Borschkegasse 8a, A-1090 Wien, Austria.
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40
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Hegyi L, Hardwick SJ, Siow RC, Skepper JN. Macrophage death and the role of apoptosis in human atherosclerosis. JOURNAL OF HEMATOTHERAPY & STEM CELL RESEARCH 2001; 10:27-42. [PMID: 11276357 DOI: 10.1089/152581601750098192] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The arterial disease atherosclerosis is responsible for severe morbidity and is the most common cause of death in the Western population. The complete pathogenesis of the disease is unknown, but multiple risk factors have been identified that correlate with the development of its complications such as heart attack and stroke. Evidence suggests that atherosclerosis is an inflammatory disease and the major cell types involved are smooth muscle cells, macrophages, and T lymphocytes. In this paper, we review the function of macrophages in the context of atherosclerosis and we also discuss the role and significance of macrophage death, including apoptosis. There is much evidence, certainly in vitro, suggesting that low-density lipoprotein becomes atherogenic when it undergoes cell-mediated oxidation within the artery wall. Besides inducing apoptosis in vitro, oxidized low-density lipoprotein may also cause extensive DNA damage in intimal cells, which might presage apoptosis. We review the results of experimental and clinical studies, which may indicate how the complications of atherosclerosis could be prevented by using different therapeutical strategies including bone marrow transplantation and gene therapy.
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Affiliation(s)
- L Hegyi
- Division of Cardiovascular Medicine, Department of Medicine, ACCI, Addenbrooke's Hospital, Cambridge, CB2 2QQ, UK.
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41
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Abstract
Oxidation products of lipids and proteins are found in atherosclerotic plaque and in macrophage foam cells. Macrophages avidly endocytose in-vitro oxidized LDL and accumulate sterols. What is the evidence that such a process is involved in in-vivo foam cell formation? The present review surveys current knowledge on the metabolism of oxidized LDL by macrophages, and the types, amounts and location of oxidation products that accumulate in these cells. Comparable studies of lesion lipoproteins and foam cells indicate that limited extracellular lipoprotein oxidation, perhaps followed by more extensive intracellular oxidation subsequent to uptake by macrophages, is a more likely scenario in vivo.
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Affiliation(s)
- W Jessup
- Cell Biology Group, Heart Research Institute, Sydney, New South Wales, Australia.
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42
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Li W, Yuan X, Nordgren G, Dalen H, Dubowchik GM, Firestone RA, Brunk UT. Induction of cell death by the lysosomotropic detergent MSDH. FEBS Lett 2000; 470:35-9. [PMID: 10722841 DOI: 10.1016/s0014-5793(00)01286-2] [Citation(s) in RCA: 203] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Controlled lysosomal rupture was initiated in lysosome-rich, macrophage-like cells by the synthetic lysosomotropic detergent, O-methyl-serine dodecylamide hydrochloride (MSDH). When MSDH was applied at low concentrations, resulting in partial lysosomal rupture, activation of pro-caspase-3-like proteases and apoptosis followed after some hours. Early during apoptosis, but clearly secondary to lysosomal destabilization, the mitochondrial transmembrane potential declined. At high concentrations, MSDH caused extensive lysosomal rupture and necrosis. It is suggested that lysosomal proteases, if released to the cytosol, may cause apoptosis directly by pro-caspase activation and/or indirectly by mitochondrial attack with ensuing discharge of pro-apoptotic factors.
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Affiliation(s)
- W Li
- Division of Pathology II, Faculty of Health Sciences, University of Linköping, S-581 85, Linköping, Sweden
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43
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Yuan XM, Li W, Brunk UT, Dalen H, Chang YH, Sevanian A. Lysosomal destabilization during macrophage damage induced by cholesterol oxidation products. Free Radic Biol Med 2000; 28:208-18. [PMID: 11281288 DOI: 10.1016/s0891-5849(99)00220-8] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have previously shown that oxidized low-density lipoprotein (LDL) induces damage to the macrophage lysosomal membranes, with ensuing leakage of lysosomal contents and macrophage cell death. Cholesterol oxidation products (ChOx) have been reported to be the major cytotoxic components of oxidized LDL/LDL- and also to stimulate cholesterol accumulation in vascular cells. In the present study, we characterized the initial events during macrophage damage induced by cholesterol oxidation products (ChOx). Within 24 h of exposure, ChOx caused lysosomal destabilization, release to the cytosol of the lysosomal marker-enzyme cathepsin D, apoptosis, and postapoptotic necrosis. Enhanced autophagocytosis and chromatin margination was found 12 h after the exposure to ChOx, whereas apoptosis and postapoptotic necrosis was pronounced 24 and 48 h after the exposure. Some lysosomal vacuoles were then filled with degraded cellular organelles, indicating phagocytosis of apoptotic bodies by surviving cells. Because caspase-3 activation was detected in the ChOx-exposed cells, lysosomal destabilization may associate with the leakage of lysosomal enzymes, and activation of the caspase cascade. MnSOD mRNA levels were markedly increased after 24 h of exposure to ChOx, suggesting associated induction of mitochondrial protection repair or turnover. We conclude that ChOx-induced damage to lysosomes and mitochondria are sequelae to the cascade of oxysterol cytotoxic events. The early disruption of lysosomes induced by ChOx, with resultant autophagocytosis may be a critical event in apoptosis and/or necrosis of macrophages/foam cells during the development of atherosclerotic lesions.
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Affiliation(s)
- X M Yuan
- Division of Pathology II, Faculty of Health Sciences, Linköping University, Sweden.
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44
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Abstract
The mitochondrial free radical theory of aging is seriously challenged by the finding that mutant mtDNA never becomes abundant in vivo, a result disputed only in experiments using novel PCR variants whose quantitative accuracy is widely doubted. However, evidence continues to mount that mitochondria are the crucial site of free radical damage in vivo, most notably that mice lacking the nonmitochondrial isoforms of superoxide dismutase are healthy. It is thus important to determine whether a low level of mutant mtDNA could have serious systemic effects. This possibility exists because of the observed mosaic distribution of mutant mtDNA: some cells (or muscle fiber segments) lack any aerobic respiration. Such cells are presumed to satisfy their ATP needs by glycolysis. In vitro, however, NADH recycling by transmembrane pyruvate/lactate exchange does not suffice: cells only survive if they can up-regulate the plasma membrane oxidoreductase (PMOR). The PMOR's physiological electron acceptor is unknown. It was proposed recently (de Grey, A. D. N. J. (1998) J. Anti-Aging Med. 1(1), 53-66) that a prominent in vivo acceptor from these mitochondrially mutant cells may be oxygen, forming extracellular superoxide. The mosaic ("hotspot") distribution of this superoxide would limit its dismutation by extracellular superoxide dismutase; it may thus reduce transition metals leading to oxidation of circulating material, such as LDL. This would raise systemic oxidative stress, greatly amplifying the damage done by the originating mitochondrially mutant cells. This model, now known as the "reductive hotspot hypothesis," has recently gained much indirect experimental support; several direct tests of it are also feasible.
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Affiliation(s)
- A D de Grey
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, United Kingdom.
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45
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Ponraj D, Makjanic J, Thong PS, Tan BK, Watt F. The onset of atherosclerotic lesion formation in hypercholesterolemic rabbits is delayed by iron depletion. FEBS Lett 1999; 459:218-22. [PMID: 10518022 DOI: 10.1016/s0014-5793(99)01199-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The theory that iron may play a significant role in atherogenesis by promoting the formation of free radicals is controversial. Previous results using the new technique of nuclear microscopy showed a seven-fold increase in iron concentrations within newly formed atherosclerotic lesions in hypercholesterolemic rabbits compared to healthy artery tissue. In a follow-up time sequence study described here, we show that iron accumulation occurs at the onset of lesion formation. In addition, weekly bleeding decreases the iron uptake into the artery wall and delays the onset of atherogenesis. These results provide direct evidence for a key role of iron in initiating atherogenesis.
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Affiliation(s)
- D Ponraj
- Research Centre for Nuclear Microscopy, Department of Physics, National University of Singapore, Singapore
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