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Roos K, Berkholz J. LDL Affects the Immunomodulatory Response of Endothelial Cells by Modulation of the Promyelocytic Leukemia Protein (PML) Expression via PKC. Int J Mol Sci 2023; 24:ijms24087306. [PMID: 37108469 PMCID: PMC10138343 DOI: 10.3390/ijms24087306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 04/04/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
In addition to its function as an intravascular lipid transporter, LDL also triggers signal transduction in endothelial cells (ECs), which, among other things, trigger immunomodulatory cascades, e.g., IL-6 upregulation. However, the molecular mechanisms of how these LDL-triggered immunological responses in ECs are realized are not fully understood. Since promyelocytic leukemia protein (PML) plays a role in promoting inflammatory processes, we examined the relationship between LDL, PML, and IL-6 in human ECs (HUVECs and EA.hy926 cells). RT-qPCR, immunoblotting, and immunofluorescence analyses showed that LDL but not HDL induced higher PML expression and higher numbers of PML-nuclear bodies (PML-NBs). Transfection of the ECs with a PML gene-encoding vector or PML-specific siRNAs demonstrated PML-regulated IL-6 and IL-8 expression and secretion after LDL exposure. Moreover, incubation with the PKC inhibitor sc-3088 or the PKC activator PMA showed that LDL-induced PKC activity leads to the upregulation of PML mRNA and PML protein. In summary, our experimental data suggest that high LDL concentrations trigger PKC activity in ECs to upregulate PML expression, which then increases production and secretion of IL-6 and IL-8. This molecular cascade represents a novel cellular signaling pathway with immunomodulatory effects in ECs in response to LDL exposure.
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Affiliation(s)
- Kerrin Roos
- Institute of Physiology, Charité-Universitätsmedizin, 10117 Berlin, Germany
| | - Janine Berkholz
- Institute of Physiology, Charité-Universitätsmedizin, 10117 Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, 10785 Berlin, Germany
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2
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Myeloperoxidase-Oxidized LDL Activates Human Aortic Endothelial Cells through the LOX-1 Scavenger Receptor. Int J Mol Sci 2022; 23:ijms23052837. [PMID: 35269979 PMCID: PMC8910860 DOI: 10.3390/ijms23052837] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 02/21/2022] [Accepted: 02/24/2022] [Indexed: 12/12/2022] Open
Abstract
Cardiovascular disease as a result of atherosclerosis is a leading cause of death worldwide. Atherosclerosis is primarily caused by the dysfunction of vascular endothelial cells and the subendothelial accumulation of oxidized forms of low-density lipoprotein (LDL). Early observations have linked oxidized LDL effects in atherogenesis to the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) scavenger receptor. It was shown that LOX-1 is upregulated by many inflammatory mediators and proatherogenic stimuli including cytokines, reactive oxygen species (ROS), hemodynamic blood flow, high blood sugar levels and, most importantly, modified forms of LDL. Oxidized LDL signaling pathways in atherosclerosis were first explored using LDL that is oxidized by copper (Cuox-LDL). In our study, we used a more physiologically relevant model of LDL oxidation and showed, for the first time, that myeloperoxidase oxidized LDL (Mox-LDL) may affect human aortic endothelial cell (HAEC) function through the LOX-1 scavenger receptor. We report that Mox-LDL increases the expression of its own LOX-1 receptor in HAECs, enhancing inflammation and simultaneously decreasing tubulogenesis in the cells. We hypothesize that Mox-LDL drives endothelial dysfunction (ED) through LOX-1 which provides an initial hint to the pathways that are initiated by Mox-LDL during ED and the progression of atherosclerosis.
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3
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Shukla H, Gaje G, Koucheki A, Lee HY, Sun X, Trush MA, Zhu H, Li YR, Jia Z. NADPH-quinone oxidoreductase-1 mediates Benzo-[a]-pyrene-1,6-quinone-induced cytotoxicity and reactive oxygen species production in human EA.hy926 endothelial cells. Toxicol Appl Pharmacol 2020; 404:115180. [PMID: 32739527 DOI: 10.1016/j.taap.2020.115180] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 07/11/2020] [Accepted: 07/28/2020] [Indexed: 11/17/2022]
Abstract
Numerous studies conducted in the past have reported deaths in the human population due to cardiovascular diseases (CVD) on exposure to air particulate matter (APM). BP-1,6-quinone (BP-1,6-Q) is one of the significant components of APM. However, the mechanism(s) by which it can exert its toxicity in endothelial cells is not yet completely understood. NAD(P)H: quinone oxidoreductase-1 (NQO1) is expressed highly in myocardium and vasculature tissues of the heart and plays a vital role in maintaining vascular homeostasis. This study, demonstrated that BP-1,6-Q diminishes NQO1 enzyme activity in a dose-dependent manner in human EA.hy926 endothelial cells. The decrease in the NQO1 enzyme causes potentiation in BP-1,6-Q-mediated toxicity in EA.hy926 endothelial cells. The enhancement of NQO1 in endothelial cells showed cytoprotection against BP-1,6-Q-induced cellular toxicity, lipid, and protein damage suggesting an essential role of NQO1 in cytoprotection against BP-1,6-Q toxicity. Using various biochemical assays and genetic approaches, results from this study further demonstrated that NQO1 also plays a crucial role in BP-1,6-Q-induced production of reactive oxygen species (ROS). These findings will contribute to elucidating BP-1,6-Q mediated toxicity and its role in the development of atherosclerosis.
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Affiliation(s)
- Halley Shukla
- Department of Biology, University of North Carolina at Greensboro, NC, USA
| | - Gabriella Gaje
- Department of Biology, University of North Carolina at Greensboro, NC, USA
| | - Ashkon Koucheki
- Department of Biology, University of North Carolina at Greensboro, NC, USA
| | - Ho Young Lee
- Department of Biology, University of North Carolina at Greensboro, NC, USA
| | - Xiaolun Sun
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Michael A Trush
- Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Hong Zhu
- Campbell University School of Osteopathic Medicine, Buies Creek, NC, USA
| | - Y Robert Li
- Campbell University School of Osteopathic Medicine, Buies Creek, NC, USA
| | - Zhenquan Jia
- Department of Biology, University of North Carolina at Greensboro, NC, USA.
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4
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Tang Y, Jin X, Xiang Y, Chen Y, Shen CX, Zhang YC, Li YG. The lncRNA MALAT1 protects the endothelium against ox-LDL-induced dysfunction via upregulating the expression of the miR-22-3p target genes CXCR2 and AKT. FEBS Lett 2015; 589:3189-96. [PMID: 26364720 DOI: 10.1016/j.febslet.2015.08.046] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 08/23/2015] [Indexed: 01/17/2023]
Abstract
CXCR2 plays a key role in protecting the integrity of the endothelium. Emerging evidence has demonstrated that the long ncRNAs (lncRNA) Human metastasis associated lung adenocarcinoma transcript 1 (MALAT1) participates in the regulation of the pathophysiological processes. However, whether there is crosstalk between CXCR2 and MALAT1 remains unknown. In this study, we demonstrated that MALAT1 was upregulated in patients with unstable angina. MALAT1 silencing significantly downregulated the expression of the miR-22-3p target gene CXCR2 via reversing the effect of the miR-22-3p, resulting in the aggravation of Oxidized low-density lipoprotein (ox-LDL)-induced endothelial injury; this process was associated with the AKT pathway. Thus, MALAT1 protects the endothelium from ox-LDL-induced endothelial dysfunction partly through competing with miR-22-3p for endogenous RNA.
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Affiliation(s)
- Yong Tang
- Department of Cardiology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xian Jin
- Department of Cardiology, Central Hospital of Minhang District, Shanghai, China; Department of Cardiology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yin Xiang
- Department of Cardiology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yu Chen
- Department of Cardiology, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Cheng-xing Shen
- Department of Cardiology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Ya-chen Zhang
- Department of Cardiology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
| | - Yi-gang Li
- Department of Cardiology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
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5
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Orekhov AN, Bobryshev YV, Sobenin IA, Melnichenko AA, Chistiakov DA. Modified low density lipoprotein and lipoprotein-containing circulating immune complexes as diagnostic and prognostic biomarkers of atherosclerosis and type 1 diabetes macrovascular disease. Int J Mol Sci 2014; 15:12807-41. [PMID: 25050779 PMCID: PMC4139876 DOI: 10.3390/ijms150712807] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 06/29/2014] [Accepted: 07/03/2014] [Indexed: 12/14/2022] Open
Abstract
In atherosclerosis; blood low-density lipoproteins (LDL) are subjected to multiple enzymatic and non-enzymatic modifications that increase their atherogenicity and induce immunogenicity. Modified LDL are capable of inducing vascular inflammation through activation of innate immunity; thus, contributing to the progression of atherogenesis. The immunogenicity of modified LDL results in induction of self-antibodies specific to a certain type of modified LDL. The antibodies react with modified LDL forming circulating immune complexes. Circulating immune complexes exhibit prominent immunomodulatory properties that influence atherosclerotic inflammation. Compared to freely circulating modified LDL; modified LDL associated with the immune complexes have a more robust atherogenic and proinflammatory potential. Various lipid components of the immune complexes may serve not only as diagnostic but also as essential predictive markers of cardiovascular events in atherosclerosis. Accumulating evidence indicates that LDL-containing immune complexes can also serve as biomarker for macrovascular disease in type 1 diabetes.
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Affiliation(s)
- Alexander N Orekhov
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Russian Academy of Medical Sciences, Moscow 125315, Russia.
| | - Yuri V Bobryshev
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Russian Academy of Medical Sciences, Moscow 125315, Russia.
| | - Igor A Sobenin
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Russian Academy of Medical Sciences, Moscow 125315, Russia.
| | - Alexandra A Melnichenko
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Russian Academy of Medical Sciences, Moscow 125315, Russia.
| | - Dimitry A Chistiakov
- Department of Medical Nanobiotechnology, Pirogov Russian State Medical University, Moscow 117997, Russia.
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6
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Low-density lipoprotein modified by myeloperoxidase in inflammatory pathways and clinical studies. Mediators Inflamm 2013; 2013:971579. [PMID: 23983406 PMCID: PMC3742028 DOI: 10.1155/2013/971579] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 06/26/2013] [Indexed: 02/07/2023] Open
Abstract
Oxidation of low-density lipoprotein (LDL) has a key role in atherogenesis. Among the different models of oxidation that have been studied, the one using myeloperoxidase (MPO) is thought to be more physiopathologically relevant. Apolipoprotein B-100 is the unique protein of LDL and is the major target of MPO. Furthermore, MPO rapidly adsorbs at the surface of LDL, promoting oxidation of amino acid residues and formation of oxidized lipoproteins that are commonly named Mox-LDL. The latter is not recognized by the LDL receptor and is accumulated by macrophages. In the context of atherogenesis, Mox-LDL accumulates in macrophages leading to foam cell formation. Furthermore, Mox-LDL seems to have specific effects and triggers inflammation. Indeed, those oxidized lipoproteins activate endothelial cells and monocytes/macrophages and induce proinflammatory molecules such as TNFα and IL-8. Mox-LDL may also inhibit fibrinolysis mediated via endothelial cells and consecutively increase the risk of thrombus formation. Finally, Mox-LDL has been involved in the physiopathology of several diseases linked to atherosclerosis such as kidney failure and consequent hemodialysis therapy, erectile dysfunction, and sleep restriction. All these issues show that the investigations of MPO-dependent LDL oxidation are of importance to better understand the inflammatory context of atherosclerosis.
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7
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Choi JH, Yoo JY, Kim SO, Yoo SE, Oh GT. KR-31543 reduces the production of proinflammatory molecules in human endothelial cells and monocytes and attenuates atherosclerosis in mouse model. Exp Mol Med 2013; 44:733-9. [PMID: 23143639 PMCID: PMC3538980 DOI: 10.3858/emm.2012.44.12.081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
KR-31543, (2S, 3R, 4S)-6-amino-4-[N-(4-chlorophenyl)- N-(2-methyl-2H-tetrazol-5-ylmethyl) amino]-3,4-dihydro- 2-dimethyoxymethyl-3-hydroxy-2-methyl-2H-1-benz opyran is a new neuroprotective agent for ischemiareperfusion damage. It has also been reported that KR-31543 has protective effects on lipid peroxidation and H₂O₂-induced reactive oxygen species production. In this study, we investigated the anti-inflammatory and anti-atherogenic properties of KR-31543. We observed that KR-31543 treatment reduced the production of MCP-1, IL-8, and VCAM-1 in HUVECs, and of MCP-1 and IL-6 in THP-1 human monocytes. We also examined the effect of KR-31543 on monocytes migration in vitro. KR-31543 treatment effectively reduced the migration of THP-1 human monocytes to the HUVEC monolayer in a dose-dependent manner. We next examined the effects of this compound on atherogenesis in LDL receptor deficient (Ldlr ⁻/⁻) mice. After 10 weeks of western diet, the formation of atherosclerotic lesion in aorta was reduced in the KR-31543-treated group compared to the control group. The accumulation of macrophages in lesion was also reduced in KR-31543 treated group. However, the plasma levels of total cholesterol, HDL, LDL, and triglyceride were not affected by KR-31543 treatment. Taken together, these results show that KR-31543 has anti-inflammatory properties on human monocytes and endothelial cells, and inhibits fatty streak lesion formation in mouse model of atherosclerosis, suggesting the potential of KR-31543 for the treatment for atherosclerosis.
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Affiliation(s)
- Jae-Hoon Choi
- Laboratory of Molecular Physiology, Department of Life Science, College of Natural Sciences, Research Institute for Natural Sciences, Hanyang University, Seoul 133-791, Kore
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Suppression of zinc finger protein 580 by high oxLDL/LDL-ratios is followed by enhanced expression of endothelial IL-8. Atherosclerosis 2011; 216:103-8. [PMID: 21310414 DOI: 10.1016/j.atherosclerosis.2011.01.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2010] [Revised: 01/07/2011] [Accepted: 01/07/2011] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The Interleukin 8 (IL-8) response of endothelial cells to lipoproteins has well known implications for the development and progression of atherosclerosis. In this study we sought for the role of zinc finger protein 580 (ZNF580) in the endothelial IL-8 response to lipoproteins. METHODS In human umbilical vein endothelial cells (HUVEC) ZNF580 and IL-8 levels were examined by real-time-RT-PCR, immunoblotting and immunostaining or ELISA, respectively. RESULTS ZNF580 is located in the nucleus and regulated by LDL and HDL depending on the oxLDL/LDL-ratio but not by TNFα. IL-8 expression profiles are inversely influenced by the oxLDL/LDL-ratio, both in vitro and in vivo. Knock down of ZNF580 enhances the expression and release of IL-8 and increases monocyte arrest under flow conditions in vitro. CONCLUSIONS ZNF580 is a novel factor in the lipoprotein-dependent regulation of IL-8 and monocyte arrest. Therefore it may be a new potential target for intervention in atherosclerosis.
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9
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Suzuki K, Sakiyama Y, Usui M, Obama T, Kato R, Itabe H, Yamamoto M. Oxidized low-density lipoprotein increases interleukin-8 production in human gingival epithelial cell line Ca9-22. J Periodontal Res 2010; 45:488-95. [PMID: 20412422 DOI: 10.1111/j.1600-0765.2009.01263.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND OBJECTIVE Recent epidemiological studies have shown a correlation between periodontitis and hyperlipidemia. We have found high levels of oxidized low-density lipoprotein (OxLDL) in the gingival crevicular fluid of dental patients. In the present study, we tried to examine the possible role of OxLDL in periodontal inflammation in vitro. MATERIAL AND METHODS Cells of the human gingival epithelial cell line Ca9-22 were cultured in media containing OxLDL, and the amounts of interleukin-8 (IL-8) and prostaglandin E(2) (PGE(2)) produced were measured using ELISAs. RESULTS Production of IL-8 by Ca9-22 cells was significantly increased when the cells were treated with OxLDL, but not with native LDL or acetylated LDL. Production of PGE(2) by Ca9-22 cells was enhanced by co-incubation with OxLDL and interleukin-1 beta (IL-1 beta). Scavenger receptor inhibitors, fucoidan and dextran sulfate, inhibited the OxLDL-induced IL-8 and PGE(2) production in the presence of IL-1 beta. The p(38) MAPK inhibitors SB203580 and SB202190 and the ERK inhibitor PD98059 inhibited the OxLDL-induced IL-8 production. Among oxidized lipids and chemically modified LDL, 7-ketocholesterol enhanced IL-8 production. CONCLUSION This is the first report to show that OxLDL enhances IL-8 production in epithelial cells.
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Affiliation(s)
- K Suzuki
- Department of Periodontology, Showa University School of Dentistry, Showa University Dental Hospital, Tokyo, Japan
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10
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Papadopoulou C, Corrigall V, Taylor PR, Poston RN. The role of the chemokines MCP-1, GRO-alpha, IL-8 and their receptors in the adhesion of monocytic cells to human atherosclerotic plaques. Cytokine 2008; 43:181-6. [PMID: 18579408 PMCID: PMC2568828 DOI: 10.1016/j.cyto.2008.05.009] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2007] [Revised: 03/17/2008] [Accepted: 05/07/2008] [Indexed: 11/04/2022]
Abstract
Monocyte adhesion to the arterial endothelium and subsequent migration into the intima are central events in the pathogenesis of atherosclerosis. Previous experimental models have shown that chemokines can enhance monocyte–endothelial adhesion by activating monocyte integrins. Our study assesses the role of chemokines IL-8, MCP-1 and GRO-α, together with their monocyte receptors CCR2 and CXCR2 in monocyte adhesion to human atherosclerotic plaques. In an adhesion assay, a suspension of monocytic U937 cells was incubated with human atherosclerotic artery sections and the levels of endothelial adhesion were quantified. Adhesion performed in the presence of a monoclonal antibody to a chemokine, chemokine receptor or of an isotype matched control immunoglobulin, shows that antibodies to all chemokines tested, as well as their receptors, inhibit adhesion compared to the control immunoglobulins. Immunohistochemistry demonstrated the expression of MCP-1, GRO-α and their receptors in the endothelial cells and intima of all atherosclerotic lesions. These results suggest that all these chemokines and their receptors can play a role in the adhesion of monocytes to human atherosclerotic plaques. Furthermore, they suggest that these chemokine interactions provide potential targets for the therapy of atherosclerosis.
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Affiliation(s)
- Charikleia Papadopoulou
- Centre for Cardiovascular Biology and Medicine, King's College London, Guy's Campus, London SE1 1UL, UK.
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11
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Boudjeltia KZ, Legssyer I, Van Antwerpen P, Kisoka RL, Babar S, Moguilevsky N, Delree P, Ducobu J, Remacle C, Vanhaeverbeek M, Brohee D. Triggering of inflammatory response by myeloperoxidase-oxidized LDL. Biochem Cell Biol 2007; 84:805-12. [PMID: 17167545 DOI: 10.1139/o06-061] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The oxidation theory proposes that LDL oxidation is an early event in atherosclerosis and that oxidized LDL contributes to atherogenesis in triggering inflammation. In contrast to the copper-modified LDL, there are few studies using myeloperoxidase-modified LDL (Mox-LDL) as an inflammation inducer. Our aim is to test whether Mox-LDL could constitute a specific inducer of the inflammatory response. Albumin, which is the most abundant protein in plasma and which is present to an identical concentration of LDL in the intima, was used for comparison. The secretion of IL-8 by endothelial cells (Ea.hy926) and TNF-alpha by monocytes (THP-1) was measured in the cell medium after exposure of these cells to native LDL, native albumin, Mox-LDL, or Mox-albumin. We observed that Mox-LDL induced a 1.5- and 2-fold increase (ANOVA; P < 0.001) in IL-8 production at 100 microg/mL and 200 microg/mL, respectively. The incubation of THP-1 cells with Mox-LDL (100 microg/mL) increased the production of TNF-alpha 2-fold over the control. Native LDL, albumin, and Mox-albumin showed no effect in either cellular types. The myeloperoxidase-modified LDL increase in cytokine release by endothelial and monocyte cells and by firing both local and systemic inflammation could induce atherogenesis and its development.
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Affiliation(s)
- Karim Zouaoui Boudjeltia
- Experimental Medicine Laboratory. Université de Bruxelles, Unit 222, ISPPC, CHU André Vésale, 706, route de Gozée, 6110 Montigny-Le-Tilleul, Belgium.
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12
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Abstract
Oxidized low-density lipoprotein (Ox-LDL) is known to be involved in the generation and progression of atherosclerosis. Ox-LDL has a number of potentially atherogenic effects on vascular cells, including uncontrol uptake by scavenger receptors. Asp-hemolysin, a hemolytic toxin from Aspergillus fumigatus, is a binding protein for Ox-LDL. This study was undertaken to clarify the binding specificity of Asp-hemolysin to Ox-LDL. We examined the binding specificity of Asp-hemolysin to Ox-LDL using several modified lipoproteins and scavenger-receptor ligands. Asp-hemolysin bound to Ox-LDL with shorter LDL oxidation times. However, Asp-hemolysin did not bind to acetylated LDL. The native high-density lipoprotein (n-HDL) and modified HDL (e.g., acetylated HDL, oxidized HDL) also had no Asp-hemolysin binding. Inhibitors of scavenger-receptor binding, including maleylated bovine serum albumin, polyinosinic acid, dextran sulfate, and fucoidin, had no effect on the binding of Ox-LDL to Asp-hemolysin. Surface plasmon-resonance studies revealed that Ox-LDL binds with high affinity (K(D)=0.63 microg/ml) to Asp-hemolysin. Furthermore, we have shown that Ox-LDL strongly inhibits the hemolytic activity of Asp-hemolysin and that the removal of lysophosphatidylcholine (lysoPC) from Ox-LDL abolished the inhibition. We also investigated the interaction between Asp-hemolysin and lysoPC as a typical lipid moiety of Ox-LDL. The binding of Asp-hemolysin to LDL oxidized for different times depended on the lysoPC content in each Ox-LDL. In addition, the inhibition of lysoPC production in Ox-LDL by phenylmethylsulfonyl fluoride (PMSF) pretreatment of LDL resulted in a marked decrease in Asp-hemolysin binding to PMSF-pretreated Ox-LDL. The binding analysis of Asp-hemolysin to lysoPC revealed that Asp-hemolysin binds directly to lysoPC. We conclude that Asp-hemolysin is a specific binding protein with high affinity for Ox-LDL and that its binding specificity is distinct from any receptor for Ox-LDL.
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Affiliation(s)
- Yoichi Kudo
- Sendai Hospital of East Japan Railway Company, Sendai, Japan.
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13
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Li SL, Dwarakanath RS, Cai Q, Lanting L, Natarajan R. Effects of silencing leukocyte-type 12/15-lipoxygenase using short interfering RNAs. J Lipid Res 2004; 46:220-9. [PMID: 15576842 DOI: 10.1194/jlr.m400328-jlr200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The leukocyte-type 12/15-lipoxygenase (12/15-LO) has been implicated in the pathogenesis of atherosclerosis, hypertension, and diabetes. 12/15-LO and its products are associated with LDL oxidation, cellular growth, migration, adhesion, and inflammatory gene expression in monocytes/macrophages, endothelial cells, and vascular smooth muscle cells (VSMCs). Our objective, therefore, was to develop novel expression vectors for short interfering RNAs (siRNAs) targeting 12/15-LO to evaluate its functional relevance in macrophages and VSMCs. We used a PCR-based approach to rapidly identify effective siRNA target sites on mouse 12/15-LO and initially tested their efficacy on a fusion construct of 12/15-LO cDNA and enhanced green fluorescent protein. We then cloned these U6 promoter+siRNA PCR products into plasmid vectors [short hairpin siRNAs (shRNAs)] to knockdown endogenous 12/15-LO expression in mouse macrophages and also rat and mouse VSMCs. Furthermore, the functional effects of shRNA-mediated 12/15-LO knockdown were noted by the reduced oxidant stress and chemokine [monocyte chemoattractant protein-1 (MCP-1)] expression in a differentiated mouse monocytic cell line as well as by the reduced cellular adhesion and fibronectin expression in VMSCs. Knocking down 12/15-LO expression also reduced the expression of inflammatory genes, MCP-1, vascular cell adhesion molecule-1, and interleukin-6 in VSMCs. Our results illustrate the functional relevance of 12/15-LO activation in macrophages and VSMCs and its relationship to oxidant stress and inflammation.
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MESH Headings
- 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid/pharmacology
- Animals
- Arachidonate 12-Lipoxygenase/genetics
- Arachidonate 12-Lipoxygenase/metabolism
- Arachidonate 15-Lipoxygenase/genetics
- Arachidonate 15-Lipoxygenase/metabolism
- Base Sequence
- Blotting, Western
- Cell Adhesion
- Cell Line
- Cell Movement
- Cells, Cultured
- Chemokine CCL2/metabolism
- Chemokines/metabolism
- DNA Primers/chemistry
- DNA, Complementary/metabolism
- Down-Regulation
- Endothelium, Vascular/metabolism
- Ethidium/analogs & derivatives
- Ethidium/pharmacology
- Fibronectins/chemistry
- Fibronectins/metabolism
- Gene Silencing
- Green Fluorescent Proteins/metabolism
- Humans
- Immunoblotting
- Inflammation
- Lipoproteins, LDL/metabolism
- Macrophages/metabolism
- Mice
- Microscopy, Fluorescence
- Molecular Sequence Data
- Monocytes/metabolism
- Myocytes, Smooth Muscle/cytology
- Oxidants/metabolism
- Oxidative Stress
- Polymerase Chain Reaction
- Promoter Regions, Genetic
- Protein Binding
- RNA, Messenger/metabolism
- RNA, Small Interfering/metabolism
- Rats
- Recombinant Fusion Proteins/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Superoxides/metabolism
- Transfection
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Affiliation(s)
- Shu-Lian Li
- Gonda Diabetes Research Center, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
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14
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Henriksen PA, Hitt M, Xing Z, Wang J, Haslett C, Riemersma RA, Webb DJ, Kotelevtsev YV, Sallenave JM. Adenoviral gene delivery of elafin and secretory leukocyte protease inhibitor attenuates NF-kappa B-dependent inflammatory responses of human endothelial cells and macrophages to atherogenic stimuli. THE JOURNAL OF IMMUNOLOGY 2004; 172:4535-44. [PMID: 15034071 DOI: 10.4049/jimmunol.172.7.4535] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Atherosclerosis is a chronic inflammatory disease affecting arterial vessels. Strategies to reduce the inflammatory responses of endothelial cells and macrophages may slow lesion development and prevent complications such as plaque rupture. The human protease human neutrophil elastase (HNE), oxidized low density lipoprotein, LPS, and TNF-alpha were chosen as model stimuli of arterial wall inflammation and led to production of the chemokine IL-8 in endothelial cells. To counteract the activity of HNE, we have examined the effects of adenoviral gene delivery of the anti-elastases elafin, previously demonstrated within human atheroma, and murine secretory leukocyte protease inhibitor (SLPI), a related molecule, on the inflammatory responses of human endothelial cells and macrophages to atherogenic stimuli. We developed a technique of precomplexing adenovirus with cationic lipid to augment adenoviral infection efficiency in endothelial cells and to facilitate infection in macrophages. Elafin overexpression protected endothelial cells from HNE-induced IL-8 production and cytotoxicity. Elafin and murine SLPI also reduced endothelial IL-8 release in response to oxidized low density lipoprotein, LPS, and TNF-alpha and macrophage TNF-alpha production in response to LPS. This effect was associated with reduced activation of the inflammatory transcription factor NF-kappaB, through up-regulation of IkappaBalpha, in both cell types. Our work suggests a novel and extended anti-inflammatory role for these HNE inhibitors working as effectors of innate immunity to protect tissues against maladaptive inflammatory responses. Our findings indicate that elafin and SLPI may be gene therapy targets for the treatment of atheroma.
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Affiliation(s)
- Peter A Henriksen
- Rayne Laboratory, Medical Research Council Centre for Inflammation Research, Medical School, University of Edinburgh, Edinburgh, United Kingdom
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15
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Abstract
Low-density lipoprotein (LDL) cholesterol is an established risk factor for coronary heart disease (CHD). In the presence of oxidative stress LDL particles can become oxidized to form a lipoprotein species that is particularly atherogenic. Indeed, oxidized LDL (oxLDL) is pro-inflammatory, it can cause endothelial dysfunction and it readily accumulates within the arterial wall. Several factors may influence the susceptibility of LDL to oxidation, including its size and composition, and the presence of endogenous antioxidant compounds, such as alpha-tocopherol. Individuals with type 2 diabetes or the metabolic syndrome have high levels of oxidative stress and consequently are at an increased risk for cardiovascular events. Reducing oxidative stress has been proposed as a potential approach to prevent CHD and antioxidant vitamins have been employed with encouraging results in experimental models of atherosclerosis. However, clinical trials have not demonstrated consistent beneficial effects of antioxidants on cardiovascular outcomes. Statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) are the first-line choice for lowering total and LDL cholesterol levels and they have been proven to reduce the risk of CHD. Recent data suggest that these compounds, in addition to their lipid-lowering ability, can also reduce the production of reactive oxygen species and increase the resistance of LDL to oxidation. It may be that the ability of statins to limit the oxidation of LDL contributes to their effectiveness at preventing atherosclerotic disease.
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Affiliation(s)
- Robert S Rosenson
- Preventive Cardiology Center, Northwestern University, The Feinberg School of Medicine, 201 E. Huron Street, Galter Pavilion, Suite 11-120, Chicago, IL 60611, USA.
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16
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Gern JE, Brockman-Schneider R, Bhattacharya S, Malter JS, Busse WW. Serum and low-density lipoprotein enhance interleukin-8 secretion by airway epithelial cells. Am J Respir Cell Mol Biol 2003; 29:483-9. [PMID: 12714378 DOI: 10.1165/rcmb.2002-0306oc] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Viral respiratory infections rapidly increase vascular permeability, which leads to the transudation of serum proteins into airway secretions and tissues. To determine whether this process activates airway epithelial cells, bronchial epithelial cells were incubated with serum, and interleukin (IL)-8 secretion and gene expression were examined. As little as 0.1% serum significantly enhanced IL-8 secretion, and maximal secretion (65 +/- 4 ng/ml, 48 h) was observed with 10% serum. Low-density lipoprotein, but not albumin or immunoglobulin G, augmented bronchial epithelial IL-8 secretion, which was partially blocked by a monoclonal antibody specific for the low-density lipoprotein receptor. The IL-8-inducing activity of plasma was also augmented by clotting and platelet activation. Mechanistically, serum activated nuclear factor-kappaB and increased the stability and steady state levels of IL-8 mRNA. In summary, specific components of serum are potent activators of IL-8 mRNA and secretion, and the increased IL-8 production is likely to be a result of both increased transcription and mRNA stability. This effect may represent an innate mechanism for the recruitment of neutrophils to the airway in response to noxious stimuli, such as viral infections, that increase vascular permeability.
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Affiliation(s)
- James E Gern
- Department of Pediatrics, University of Wisconsin-Madison, Madison, WI 53792-9988, USA.
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17
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Suriyaphol P, Fenske D, Zähringer U, Han SR, Bhakdi S, Husmann M. Enzymatically modified nonoxidized low-density lipoprotein induces interleukin-8 in human endothelial cells: role of free fatty acids. Circulation 2002; 106:2581-7. [PMID: 12427655 DOI: 10.1161/01.cir.0000038366.11851.d0] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Treatment of low-density lipoprotein (LDL) with a protease and cholesterolesterase transforms the lipoprotein to an entity that resembles lipoprotein particles in atherosclerotic lesions, which have a high content of free cholesterol, reflecting extensive de-esterification in the intima. Because de-esterification would occur beneath the endothelium, we examined the effects of enzymatically modified LDL (E-LDL) on cultured endothelial cells. METHODS AND RESULTS Incubation of endothelial cells with E-LDL provoked selective accumulation of interleukin (IL)-8 mRNA and production of the cytokine. Chemical analyses and depletion experiments indicated that the effect was caused by the presence of free fatty acids in the altered lipoprotein. Reconstitution studies demonstrated that the oleic and linoleic acids associated with E-LDL are particularly effective IL-8 inducers. The effects of E-LDL on endothelial cells could be abrogated with albumin. CONCLUSION IL-8 is required for rolling monocytes to adhere firmly to the endothelium; thus, the findings reveal a link between subendothelial entrapment of LDL, cleavage of cholesterol esters, and monocyte recruitment into the lesion.
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Affiliation(s)
- Prapat Suriyaphol
- Institute of Medical Microbiology and Hygiene, University of Mainz, Germany
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18
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Ishii J, Adachi H, Aoki J, Koizumi H, Tomita S, Suzuki T, Tsujimoto M, Inoue K, Arai H. SREC-II, a new member of the scavenger receptor type F family, trans-interacts with SREC-I through its extracellular domain. J Biol Chem 2002; 277:39696-702. [PMID: 12154095 DOI: 10.1074/jbc.m206140200] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The scavenger receptor expressed by endothelial cells (SREC) with an extremely large cytoplasmic domain, was originally identified in a human endothelial cell line. In this study, we have cloned a second isoform named SREC-II and shown that there is a heterophilic interaction between SREC-I and -II at their extracellular domains. The cDNA for murine SREC-II encodes an 834-amino acid protein with 35% homology to SREC-I. Similar to SREC-I, SREC-II contains multiple epidermal growth factor-like repeats in its extracellular domain. However, in contrast to SREC-I, SREC-II had little activity to internalize modified low density lipoproteins (LDL). A Northern blot analysis revealed a tissue expression pattern of SREC-II similar to that of SREC-I with predominant expression in human heart, lung, ovary, and placenta. Mouse fibroblast L cells with no tendency to associate showed noticeable aggregation when SREC-I was overexpressed in these cells, whereas overexpression of SREC-II caused only slight aggregation. Remarkably, intense aggregation was observed when SREC-I-expressing cells were mixed with those expressing SREC-II. Deletion of almost all of the cytoplasmic receptor domain had no effect on the receptor expression and cell aggregation, indicating that solely the extracellular domain is involved in cell aggregation. The association of SREC-I and -II was effectively suppressed by the presence of scavenger receptor ligands such as acetylated LDL and oxidized LDL. These findings suggest that SREC-I and -II show weak cell-cell interaction by their extracellular domains (termed homophilic trans-interaction) but display strong heterophilic trans-interaction through the extracellular epidermal growth factor-like repeat domains.
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MESH Headings
- Amino Acid Sequence
- Animals
- Blotting, Northern
- CHO Cells
- Cell Adhesion Molecules
- Cell Division
- Cloning, Molecular
- Cricetinae
- DNA, Complementary/metabolism
- Databases as Topic
- Expressed Sequence Tags
- Gene Deletion
- Humans
- Leukocytes/metabolism
- Lipoproteins/metabolism
- Mice
- Molecular Sequence Data
- Oxygen/metabolism
- Phosphorylation
- Protein Binding
- Protein Structure, Tertiary
- Receptors, Cell Surface/chemistry
- Receptors, Cell Surface/metabolism
- Receptors, LDL/chemistry
- Receptors, LDL/metabolism
- Receptors, Scavenger
- Scavenger Receptors, Class F
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Tissue Distribution
- Transfection
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Affiliation(s)
- Junko Ishii
- Laboratory of Cellular Biochemistry, RIKEN (the Institute of Physical and Chemical Research), 2-1 Wako-shi, Saitama 351-0198, Japan
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19
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Murphy N, Grimsditch DC, Parkin S, Vidgeon-Hart MP, Overend P, Groot PHE, Graham A, Benson GM. Hypercholesterolaemia and circulating levels of CXC chemokines in apoE*3 Leiden mice. Atherosclerosis 2002; 163:69-77. [PMID: 12048123 DOI: 10.1016/s0021-9150(01)00755-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hyperlipidaemia may accelerate the development of atherosclerosis by enhancing the expression of chemokines by cells within the arterial wall. Chemokines of the CC subfamily are clearly implicated in atherogenesis; however, recent reports suggest that CXC chemokines may play a hitherto unrecognised role in monocyte recruitment into atheromatous lesions expressing these molecules. Here, we examine whether circulating levels of CXC chemokines may reflect the pathogenic changes occurring during early atherogenesis. ApoE*3 Leiden mice developed marked hypercholesterolaemia, and early Type I 'fatty streak' lesions, following consumption of an atherogenic diet high in saturated fat and cholesterol, and containing sodium cholate, for up to 4 weeks. By contrast, their non-transgenic littermates (C57BL/6J) exhibited a much less pronounced hypercholesterolaemia and did not develop fatty streak lesions, when fed the same diet. Under these conditions, serum concentrations of CXC chemokines, KC and Macrophage Inflammatory Protein-2 (MIP-2) were significantly (P<or=0.0005) elevated in apoE*3 Leiden mice consuming HFC/C diet, compared with apoE*3 Leiden mice consuming a chow diet. Further, serum concentrations of KC were significantly (P<0.02) higher at 4 weeks in apoE*3 Leiden mice fed HFC/C diet compared with their non-transgenic littermates consuming the same diet. Expression of KC mRNA was detected in both aortic and hepatic tissues of apoE*3 Leiden mice, and the non-transgenic controls. Thus, hypercholesterolaemia is associated with elevated serum concentrations of CXC chemokines, KC and MIP-2 that probably reflect chronic inflammation during atherogenesis.
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Affiliation(s)
- Nuala Murphy
- Department of Biochemistry and Molecular Biology, Royal Free and University College Medical School of UCL, Royal Free Campus, Rowland Hill Street, London, UK
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20
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Yoshisue H, Suzuki K, Kawabata A, Ohya T, Zhao H, Sakurada K, Taba Y, Sasaguri T, Sakai N, Yamashita S, Matsuzawa Y, Nojima H. Large scale isolation of non-uniform shear stress-responsive genes from cultured human endothelial cells through the preparation of a subtracted cDNA library. Atherosclerosis 2002; 162:323-34. [PMID: 11996952 DOI: 10.1016/s0021-9150(01)00735-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To investigate the molecular mechanisms responsible for the regional selectivity of early atherogenesis, we have applied a non-uniform shear stress to cultured human umbilical vein endothelial cells (HUVEC). We used a microcarrier culture system and a combination of subtraction and reverse-subtraction methods to isolate a number of genes upregulated by shear stress. The resultant subtracted library includes several known genes (e.g. MCP-1, TM) whose responsiveness to shear stress has been previously reported, indicating that the library is enriched for genes upregulated by shear stress. Also included are atherosclerosis-related genes (e.g. CTGF, IL-8) whose responsiveness to shear stress had not been demonstrated, other known genes whose relationship to atherosclerosis had not been reported, and novel genes. Some responsive to centrifugal force and shear stress (RECS) genes are also upregulated following stimulation by steady laminar shear stress in a parallel plate chamber. Interestingly, the library includes ET-1 and PAI, which are well known atherogenic factors that are downregulated by laminar shear stress. This implies that turbulent shear stress has effects on HUVEC that are different from those elicited by laminar shear stress. Importantly, analysis of specimens taken from human aorta showed that several RECS genes are transcriptionally upregulated in atherosclerotic lesions, suggesting that the subtracted library includes novel therapeutic targets for the treatment of atherosclerosis.
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Affiliation(s)
- Hajime Yoshisue
- Tokyo Research Laboratories, Kyowa Hakko Kogyo Co., Ltd., 3-6-6 Asahi-machi, Machida, 194-8533, Tokyo, Japan
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21
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Abstract
(1) Chemokines play a central role in the pathogenesis of atherosclerosis, contributing to leukocyte recruitment, angiogenesis and also proliferation and migration of smooth muscle cells into atherosclerotic plaques. (2) Leukocytes and endothelial cells are an important source of chemokines, and many of the risk factors associated with atherosclerosis increase chemokine expression. There is now a body of evidence to suggest that interactions between cells such as leukocytes and endothelial cells amplify chemokine release, and this may contribute to sustained chemokine generation in inflammatory conditions. (3) This article summarises, briefly, what is currently known about chemokines release. A number of important pharmacological strategies used in the treatment of atherosclerosis inhibit chemokine release and the extent to which this may contribute to their therapeutic effect will be discussed. Understanding the mechanisms controlling chemokine expression is essential for the design of specific therapeutic interventions in atherosclerosis.
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Affiliation(s)
- Anne Burke-Gaffney
- Unit of Critical Care, National Heart and Lung Institute Division, Imperial College of Science, Technology and Medicine, Dovehouse Street, London SW3 6LY, UK.
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22
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Dwivedi A, Anggård EE, Carrier MJ. Oxidized LDL-mediated monocyte adhesion to endothelial cells does not involve NFkappaB. Biochem Biophys Res Commun 2001; 284:239-44. [PMID: 11374896 DOI: 10.1006/bbrc.2001.4955] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Oxidised LDL (oxLDL) is a key pathogenic mediator of atherogenesis, exhibiting many proatherogenic properties. We have examined the effect of oxLDL on monocyte adhesion in the endothelial cell line, EA.hy 926. This has included the role of endothelial cell adhesion molecule expression (ICAM-1 and VCAM-1), monocyte chemoattractant protein-1 (MCP-1), and the transcription factor NFkappaB in this interaction. In response to oxLDL (10-100 microg/ml), monocyte adhesion to cells increased dose-dependently. Adhesion of oxLDL at 100 microg/ml was equivalent to that seen with TNFalpha (10 ng/ml). Unmodified LDL (nLDL, 100 microg/ml) had no effect. Both oxLDL and nLDL increased MCP-1 mRNA levels. Interestingly, oxLDL had no effect on the expression of ICAM-1 and VCAM-1. In addition NFkappaB was not activated as shown by western blots of IkappaB-alpha degradation and electrophoretic mobility shift assay. In summary these data show that increased monocyte adhesion to EA.hy 926 cells occurs independently of ICAM-1, VCAM-1, and NFkappaB activation and may involve novel adhesive mechanisms.
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Affiliation(s)
- A Dwivedi
- Department of Experimental Therapeutics, William Harvey Research Institute, St. Bartholomew's and The Royal London School of Medicine and Dentistry School, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, United Kingdom
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23
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De Castellarnau C, Sánchez-Quesada JL, Benítez S, Rosa R, Caveda L, Vila L, Ordóñez-Llanos J. Electronegative LDL from normolipemic subjects induces IL-8 and monocyte chemotactic protein secretion by human endothelial cells. Arterioscler Thromb Vasc Biol 2000; 20:2281-7. [PMID: 11031216 DOI: 10.1161/01.atv.20.10.2281] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The presence in plasma of an electronegative LDL subfraction [LDL(-)] cytotoxic for endothelial cells (ECs) has been reported. We studied the effect of LDL(-) on the release by ECs of molecules implicated in leukocyte recruitment [interleukin-8 (IL-8) and monocyte chemotactic protein-1 (MCP-1)] and in the plasminogen activator inhibitor-1 (PAI-1). LDL(-), isolated by anion-exchange chromatography, differed from nonelectronegative LDL [LDL(+)] in its higher triglyceride, nonesterified fatty acid, apoprotein E and apoprotein C-III, and sialic acid contents. No evidence of extensive oxidation was found in LDL(-); its antioxidant and thiobarbituric acid-reactive substances contents were similar to those of LDL(+). However, conjugated dienes were increased in LDL(-), which suggests that mild oxidation might affect these particles. LDL(-) increased, in a concentration-dependent manner, the release of IL-8 and MCP-1 by ECs and was a stronger inductor of both chemokines than oxidized LDL (oxLDL) or LDL(+). PAI-1 release increased slightly in ECs incubated with both LDL(-) and oxLDL but not with LDL(+). However, no cytotoxic effects of LDL(-) were observed on ECs. Actinomycin D inhibited the release of IL-8 and MCP-1 induced by LDL(-) and oxLDL by up to 80%, indicating that their production is mediated by protein synthesis. Incubation of ECs with N:-acetyl cysteine inhibited production of IL-8 and MCP-1 induced by LDL(-) and oxLDL by >50%. The free radical scavenger butylated hydroxytoluene slightly inhibited the effect of oxLDL but did not modify the effect of LDL(-). An antagonist (BN-50730) of the platelet-activating factor receptor inhibited production of both chemokines by LDL(-) and oxLDL in a concentration-dependent manner. Our results indicate that LDL(-) shows proinflammatory activity on ECs and may contribute to early atherosclerotic events.
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Affiliation(s)
- C De Castellarnau
- Institut de Recerca, Servei de Bioquímica, Hospital de la Santa Creui Sant Pau, Barcelona, Spain.
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24
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Baum MK, Miguez-Burbano MJ, Campa A, Shor-Posner G. Selenium and interleukins in persons infected with human immunodeficiency virus type 1. J Infect Dis 2000; 182 Suppl 1:S69-73. [PMID: 10944486 DOI: 10.1086/315911] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
An important role for selenium in human immunodeficiency virus (HIV) disease has been proposed. Decreased selenium levels, as found in persons with HIV infection or AIDS, are sensitive markers of disease progression. Selenium deficiency, an independent predictor of mortality in both HIV-1-infected adults and children, is an essential micronutrient that is associated with an improvement of T cell function and reduced apoptosis in animal models. In addition, adequate selenium may enhance resistance to infections through modulation of interleukin (IL) production and subsequently the Th1/Th2 response. Selenium supplementation up-regulates IL-2 and increases activation, proliferation, differentiation, and programmed cell death of T helper cells. Moreover, selenium supplementation may down-regulate the abnormally high levels of IL-8 and tumor necrosis factor-alpha observed in HIV disease, which has been associated with neurologic damage, Kaposi's sarcoma, wasting syndrome, and increased viral replication. Together, these findings suggest a new mechanism through which selenium may affect HIV-1 disease progression.
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Affiliation(s)
- M K Baum
- Department of Psychiatry and Behavioral Sciences, University of Miami School of Medicine, Miami, FL 33136, USA.
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25
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Claise C, Edeas M, Chaouchi N, Chalas J, Capel L, Kalimouttou S, Vazquez A, Lindenbaum A. Oxidized-LDL induce apoptosis in HUVEC but not in the endothelial cell line EA.hy 926. Atherosclerosis 1999; 147:95-104. [PMID: 10525130 DOI: 10.1016/s0021-9150(99)00170-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
We studied the cytotoxic effect of copper-oxidized LDL in human primary human umbilical vein endothelial cells (HUVEC) and the immortalized EA.hy 926 cell line. Copper oxidized LDL (50-200 microg apoB/ml) induced concentration-dependent apoptotic cell death in HUVEC but did not induce apoptosis in EA.hy 926 cells. Only necrotic EA.hy 926 cells were evidenced at all copper oxidized LDL concentrations (25-200 microg apoB/ml), oxidation states (lightly, moderately and extensively copper-oxidized LDL) and incubation periods (4, 8 and 20 h). The different mechanisms of cell death induced by copper-oxidized LDL in EA.hy 926 cells and HUVEC may be related to various factors such as cytokines. In this study, we investigated whether interleukin-8 may be implicated in this process. The interleukin-8 production was increased in EA.hy 926 cells but not in HUVEC incubated with oxidized LDL. This increase in EA.hy 926 cells was associated with necrosis but not apoptosis. Nevertheless, the addition of interleukin-8 to HUVEC did not inhibit apoptosis induced by oxidized LDL. As the lower antioxidant capacity of EA.hy 926 cells results in higher sensitivity to oxidized LDL cytotoxicity (as we previously described), the redox status of cells may also control the form of endothelial cell death. In atherosclerotic lesions, the formation of apoptotic endothelial cells may result in part from the induction by oxidized LDL.
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Affiliation(s)
- C Claise
- Department of Biochemistry, Hospital Antoine Béclère, 157 rue de la Porte de Trivaux, 92141, Clamart, France.
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26
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Affiliation(s)
- H Itabe
- Department of Microbiology and Molecular Pathology, Faculty of Pharmaceutical Sciences, Teikyo University, Kanagawa, Japan.
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