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Effect of Sphingomyelinase-Treated LDLs on HUVECs. Molecules 2023; 28:molecules28052100. [PMID: 36903354 PMCID: PMC10004656 DOI: 10.3390/molecules28052100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/16/2023] [Accepted: 02/17/2023] [Indexed: 03/12/2023] Open
Abstract
Low-density lipoproteins (LDLs) exert a key role in the transport of esterified cholesterol to tissues. Among the atherogenic modifications of LDLs, the oxidative modification has been mainly investigated as a major risk factor for accelerating atherogenesis. Since LDL sphingolipids are also emerging as important regulators of the atherogenic process, increasing attention is devoted to the effects of sphingomyelinase (SMase) on LDL structural and atherogenic properties. The aims of the study were to investigate the effect of SMase treatment on the physical-chemical properties of LDLs. Moreover, we evaluated cell viability, apoptosis, and oxidative and inflammatory status in human umbilical vein endothelial cells (HUVECs) treated with either ox-LDLs or SMase-treated LDLs (SMase-LDLs). Both treatments were associated with the accrual of the intracellular ROS and upregulation of the antioxidant Paraoxonase 2 (PON2), while only SMase-LDLs induced an increase of superoxide dismutase 2 (SOD2), suggesting the activation of a feedback loop to restrain the detrimental effects of ROS. The increased caspase-3 activity and reduced viability observed in cells treated with SMase-LDLs and ox-LDLs suggest a pro-apoptotic effect of these modified lipoproteins on endothelial cells. Moreover, a strong proinflammatory effect of SMase-LDLs compared to ox-LDLs was confirmed by an increased activation of NF-κB and consequent increased expression of its downstream cytokines IL-8 and IL-6 in HUVECs.
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Maretti-Mira AC, Golden-Mason L, Salomon MP, Kaplan MJ, Rosen HR. Cholesterol-Induced M4-Like Macrophages Recruit Neutrophils and Induce NETosis. Front Immunol 2021; 12:671073. [PMID: 34012454 PMCID: PMC8126646 DOI: 10.3389/fimmu.2021.671073] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 04/20/2021] [Indexed: 01/11/2023] Open
Abstract
The liver is the central organ for cholesterol synthesis and homeostasis. The effects of dietary cholesterol on hepatic injury, mainly of oxidized low-density lipoproteins (OxLDL), are not fully understood. Here, we show that the degree of cholesterol oxidation had different impacts on the global gene expression of human M2-like macrophages, with highly oxidized LDL causing the most dramatic changes. M2-like macrophages and Kupffer cells undergo M4-like polarization, decreasing the expression of important markers, such as IL10, MRC1, and CD163. These cells also displayed functional changes, with reduced phagocytic capacity, increased neutrophil recruitment, and more effective neutrophil extracellular traps (NETs) induction. Our findings provide a link between LDL oxidation and modification of peripheral and liver macrophage function.
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Affiliation(s)
- Ana C Maretti-Mira
- Department of Medicine, Keck School of Medicine, Gastroenterology & Hepatology, Research Center for Liver Disease, University of Southern California (USC), Los Angeles, CA, United States
| | - Lucy Golden-Mason
- Department of Medicine, Keck School of Medicine, Gastroenterology & Hepatology, Research Center for Liver Disease, University of Southern California (USC), Los Angeles, CA, United States
| | - Matthew P Salomon
- Department of Medicine, Keck School of Medicine, Gastroenterology & Hepatology, Research Center for Liver Disease, University of Southern California (USC), Los Angeles, CA, United States
| | - Mariana J Kaplan
- Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, United States
| | - Hugo R Rosen
- Department of Medicine, Keck School of Medicine, Gastroenterology & Hepatology, Research Center for Liver Disease, University of Southern California (USC), Los Angeles, CA, United States
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He L, Zhao X, He L. LINC01140 Alleviates the Oxidized Low-Density Lipoprotein-Induced Inflammatory Response in Macrophages via Suppressing miR-23b. Inflammation 2020; 43:66-73. [PMID: 31748847 DOI: 10.1007/s10753-019-01094-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Our previous study has demonstrated that miR-23b enhances oxidized low-density lipoprotein (oxLDL)-induced inflammatory response of macrophages through the A20/NF-κB signaling pathway, thus contributing to atherosclerosis. This study aims to further investigate the upstream regulators of miR-23b in mediating oxLDL-induced inflammatory response. Human monocyte cell line THP1 was induced to differentiate into macrophages followed by the oxLDL stimulation of inflammatory response. The expression of miR-23b, LINC01140, and p53 mRNA was detected by quantitative PCR. The combination of miR-23b and LINC01140 was confirmed by luciferase reporter assay and RNA immunoprecipitation. The binding of p53 and LINC01140 promoter was determined by luciferase reporter assay. The level of inflammatory cytokines, including MCP-1, TNF-α, and IL-1β, was assessed by enzyme-linked immunosorbent assay. LINC01140 was downregulated, while p53 and miR-23b were upregulated in oxLDL-induced inflammatory response of macrophages. Overexpression of LINC01140 reduced NF-κB activity by reducing miR-23b and increasing A20. The transcription of LINC01140 was inhibited by binding of p53 and the LINC01140 promoter region. Knockdown of p53 significantly reduced NF-κB activity and level of inflammatory cytokines by promoting LINC01140 expression. Our findings demonstrated that LINC01140 acts as an anti-inflammatory factor through negatively regulating miR-23/A20 axis. In addition, p53 is identified as a transcriptional repressor of LINC01140.
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Affiliation(s)
- Liping He
- Department of Cardiology, People's Hospital of Inner Mongolia Autonomous region, No. 20 of Zhaowuda Road, Hohhot city, 010020, Inner Mongolia, China
| | - Xingsheng Zhao
- Department of Cardiology, People's Hospital of Inner Mongolia Autonomous region, No. 20 of Zhaowuda Road, Hohhot city, 010020, Inner Mongolia, China.
| | - Leping He
- The Center of Computer Information, People's Hospital of Inner Mongolia Autonomous region, Hohhot, 010020, Inner Mongolia, China
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Cimmino G, Cirillo P, Conte S, Pellegrino G, Barra G, Maresca L, Morello A, Calì G, Loffredo F, De Palma R, Arena G, Sawamura T, Ambrosio G, Golino P. Oxidized low-density lipoproteins induce tissue factor expression in T-lymphocytes via activation of lectin-like oxidized low-density lipoprotein receptor-1. Cardiovasc Res 2019; 116:1125-1135. [DOI: 10.1093/cvr/cvz230] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 07/17/2019] [Accepted: 08/21/2019] [Indexed: 12/11/2022] Open
Abstract
Abstract
Aims
T-lymphocytes plays an important role in the pathophysiology of acute coronary syndromes. T-cell activation in vitro by pro-inflammatory cytokines may lead to functional tissue factor (TF) expression, indicating a possible contribution of immunity to thrombosis. Oxidized low-density lipoproteins (oxLDLs) are found abundantly in atherosclerotic plaques. We aimed at evaluating the effects of oxLDLs on TF expression in T cells and the role of the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1).
Methods and results
CD3+ cells were isolated from healthy volunteers. Gene, protein, and surface expression of TF, as well as of LOX-1, were assessed at different time-points after oxLDL stimulation. To determine whether oxLDL-induced TF was LOX-1 dependent, T cells were pre-incubated with an LOX-1 inhibiting peptide (L-RBP) or with an anti-LOX-1 blocking antibody. To exclude that TF expression was mediated by reactive oxygen species (ROS) generation, oxLDL-stimulated T cells were pre-incubated with superoxide dismutase + catalase or with 4-Hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol), an intracellular free radical scavenger. Finally, to determine if the observed findings in vitro may have a biological relevance, the presence of CD3+/TF+/LOX-1+ cells was evaluated by immunofluorescence in human carotid atherosclerotic lesions. oxLDLs induced functionally active TF expression in T cells in a dose- and time-dependent manner, independently on ROS generation. No effect was observed in native LDL-treated T cells. LOX-1 expression was also induced by oxLDLs in a time- and dose-dependent manner. Pre-incubation with L-RBP or anti-LOX-1 antibody almost completely inhibited oxLDL-mediated TF expression. Interestingly, human carotid plaques showed significant infiltration of CD3+ cells (mainly CD8+ cells), some of which were positive for both TF and LOX-1.
Conclusion
oxLDLs induce functional TF expression in T-lymphocytes in vitro via interaction of oxLDLs with LOX-1. Human carotid atherosclerotic plaques contain CD3+/CD8+cells that express both TF and LOX-1, indicating that also in patients these mechanisms may play an important role.
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Affiliation(s)
- Giovanni Cimmino
- Department of Translational Medical Sciences, Section of Cardiology, University of Campania “Luigi Vanvitelli”, c/o Monaldi Hospital, Via L. Bianchi, 1, 80131 Naples, Italy
| | - Plinio Cirillo
- Department of Advanced Biomedical Sciences, Section of Cardiology, University of Naples “Federico II”, Naples, Italy
| | - Stefano Conte
- Department of Translational Medical Sciences, Section of Cardiology, University of Campania “Luigi Vanvitelli”, c/o Monaldi Hospital, Via L. Bianchi, 1, 80131 Naples, Italy
| | - Grazia Pellegrino
- Department of Advanced Biomedical Sciences, Section of Cardiology, University of Naples “Federico II”, Naples, Italy
| | - Giusi Barra
- Department of Clinical and Experimental Medicine, Section of Clinical Immunology, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Lucio Maresca
- Vascular Surgery Unit, Monaldi Hospital, Naples, Italy
| | - Andrea Morello
- Department of Advanced Biomedical Sciences, Section of Cardiology, University of Naples “Federico II”, Naples, Italy
| | - Gaetano Calì
- Endocrinology and Experimental Oncology Institute, CNR, Naples, Italy
| | - Francesco Loffredo
- Department of Translational Medical Sciences, Section of Cardiology, University of Campania “Luigi Vanvitelli”, c/o Monaldi Hospital, Via L. Bianchi, 1, 80131 Naples, Italy
- Molecular Cardiology, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Raffaele De Palma
- Department of Clinical and Experimental Medicine, Section of Clinical Immunology, University of Campania “Luigi Vanvitelli”, Naples, Italy
- Institute of Protein Biochemistry, CNR, Naples, Italy
| | - Giulia Arena
- Department of Translational Medical Sciences, Section of Cardiology, University of Campania “Luigi Vanvitelli”, c/o Monaldi Hospital, Via L. Bianchi, 1, 80131 Naples, Italy
| | - Tatsuya Sawamura
- Department of Physiology, Shinshu University School of Medicine, Asahi, Japan
| | | | - Paolo Golino
- Department of Translational Medical Sciences, Section of Cardiology, University of Campania “Luigi Vanvitelli”, c/o Monaldi Hospital, Via L. Bianchi, 1, 80131 Naples, Italy
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Electronegative Low-Density Lipoprotein L5 Impairs Viability and NGF-Induced Neuronal Differentiation of PC12 Cells via LOX-1. Int J Mol Sci 2017; 18:ijms18081744. [PMID: 28800073 PMCID: PMC5578134 DOI: 10.3390/ijms18081744] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 08/05/2017] [Accepted: 08/07/2017] [Indexed: 12/30/2022] Open
Abstract
There have been striking associations of cardiovascular diseases (e.g., atherosclerosis) and hypercholesterolemia with increased risk of neurodegeneration including Alzheimer's disease (AD). Low-density lipoprotein (LDL), a cardiovascular risk factor, plays a crucial role in AD pathogenesis; further, L5, a human plasma LDL fraction with high electronegativity, may be a factor contributing to AD-type dementia. Although L5 contributing to atherosclerosis progression has been studied, its role in inducing neurodegeneration remains unclear. Here, PC12 cell culture was used for treatments with human LDLs (L1, L5, or oxLDL), and subsequently cell viability and nerve growth factor (NGF)-induced neuronal differentiation were assessed. We identified L5 as a neurotoxic LDL, as demonstrated by decreased cell viability in a time- and concentration-dependent manner. Contrarily, L1 had no such effect. L5 caused cell damage by inducing ATM/H2AX-associated DNA breakage as well as by activating apoptosis via lectin-like oxidized LDL receptor-1 (LOX-1) signaling to p53 and ensuring cleavage of caspase-3. Additionally, sublethal L5 long-termly inhibited neurite outgrowth in NGF-treated PC12 cells, as evidenced by downregulation of early growth response factor-1 and neurofilament-M. This inhibitory effect was mediated via an interaction between L5 and LOX-1 to suppress NGF-induced activation of PI3k/Akt cascade, but not NGF receptor TrkA and downstream MAPK pathways. Together, our data suggest that L5 creates a neurotoxic stress via LOX-1 in PC12 cells, thereby leading to impairment of viability and NGF-induced differentiation. Atherogenic L5 likely contributes to neurodegenerative disorders.
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Zhang N, Song Y, Wu D, Xu T, Lu M, Zhang W, Wang H. Detection of 1,N(2)-propano-2'-deoxyguanosine adducts in genomic DNA by ultrahigh performance liquid chromatography-electrospray ionization-tandem mass spectrometry in combination with stable isotope dilution. J Chromatogr A 2016; 1450:38-44. [PMID: 27179676 DOI: 10.1016/j.chroma.2016.04.067] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 04/11/2016] [Accepted: 04/24/2016] [Indexed: 12/31/2022]
Abstract
Crotonaldehyde (Cro) is one of widespread and genotoxic α,β-unsaturated aldehydes and can react with the exocyclic amino group of 2'-deoxyguanosine (dG) in genomic DNA to form 1,N(2)-propano-2'-deoxyguanosine (ProdG) adducts. In this study, two diastereomers of high purity were prepared, including non-isotope and stable isotope labeled ProdG adducts, and exploited stable isotope dilution-based calibration method. By taking advantage of synthesized ProdG standards, we developed a sensitive ultrahigh performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI-MS/MS) method for accurate quantification of two diastereomers of ProdG adducts. In addition to optimization of the UHPLC separation, ammonium bicarbonate (NH4HCO3) was used as additive in the mobile phase for enhancing the ionization efficiency to ProdG adducts and facilitating MS detection. The limits of detection (LODs, S/N=3) and the limits of quantification (LOQs, S/N=10) are estimated about 50 amol and 150 amol, respectively. By the use of the developed method, both diastereomers of ProdG adducts can be detected in untreated human MRC5 cells with a frequency of 2.4-3.5 adducts per 10(8) nucleotides. Crotonaldehyde treatment dramatically increases the levels of ProdG adducts in human MRC5 in a concentration-dependent manner.
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Affiliation(s)
- Ning Zhang
- Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai 200237, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yuanyuan Song
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Danni Wu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Tian Xu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Meiling Lu
- Chemical Analysis Group, Agilent Technologies, Beijing 100102, China
| | - Weibing Zhang
- Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai 200237, China.
| | - Hailin Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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Suo J, Zhao L, Wang J, Zhu Z, Zhang H, Gao R. Influenza virus aggravates the ox-LDL-induced apoptosis of human endothelial cells via promoting p53 signaling. J Med Virol 2015; 87:1113-23. [PMID: 25777161 DOI: 10.1002/jmv.24166] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2015] [Indexed: 12/13/2022]
Abstract
Oxidized low-density lipoprotein (ox-LDL) is well recognized to play a key role in the development of atherosclerosis. And influenza virus infection has been also recognized to promote the atherosclerosis onset and progressing. However, little is known about the mechanism into it. In present study, we investigated the infection of A/Porto Rico/8/1934 (H1N1) (PR8) influenza virus in human endothelial Eahy926 cells, and determined the induction of apoptosis by the virus infection in the cell. Then we investigated the apoptosis induced by ox-LDL in Eahy926 cells, determined the influence of influenza virus infection on the ox-LDL-induced apoptosis in Eahy926 cells. Results demonstrated that PR8 virus infected human endothelial Eahy926 cells, forming plaques and replicated efficiently in the cell. And the virus infection promoted apoptosis in the cell, upregulated cytchrome c release, activated caspase 3. And what's more, we found that combined PR8 virus infection and ox-LDL treatment promoted higher level of apoptosis and higher level of the activation of apoptosis-associated molecules. Further examination indicated that the p53 signaling was more significantly promoted by both treatments. Therefore, present study confirmed that influenza virus aggravated the ox-LDL-induced apoptosis of human endothelial Eahy926 cells via promoting p53 signaling.
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Affiliation(s)
- Jing Suo
- Department of Obstetrics and Gynecology, The Affiliated Hospital of Inner Mongolia Medical University, Hohhot, China
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8
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Wan Ahmad WNH, Sakri F, Mokhsin A, Rahman T, Mohd Nasir N, Abdul-Razak S, Md Yasin M, Mohd Ismail A, Ismail Z, Nawawi H. Low serum high density lipoprotein cholesterol concentration is an independent predictor for enhanced inflammation and endothelial activation. PLoS One 2015; 10:e0116867. [PMID: 25614985 PMCID: PMC4304817 DOI: 10.1371/journal.pone.0116867] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 12/15/2014] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Inflammation, endothelial activation and oxidative stress have been established as key events in the initiation and progression of atherosclerosis. High-density lipoprotein cholesterol (HDL-c) is protective against atherosclerosis and coronary heart disease, but its association with inflammation, endothelial activation and oxidative stress is not well established. OBJECTIVES (1) To compare the concentrations of biomarkers of inflammation, endothelial activation and oxidative stress in subjects with low HDL-c compared to normal HDL-c; (2) To examine the association and correlation between HDL-c and these biomarkers and (3) To determine whether HDL-c is an independent predictor of these biomarkers. METHODS 422 subjects (mean age±SD = 43.2±11.9 years) of whom 207 had low HDL-c concentrations (HDL-c <1.0 mmol/L and <1.3 mmol/L for males and females respectively) and 215 normal controls (HDL-c ≥1.0 and ≥1.3 mmol/L for males and females respectively) were recruited in this study. The groups were matched for age, gender, ethnicity, smoking status, diabetes mellitus and hypertension. Fasting blood samples were collected for analysis of biomarkers of inflammation [high-sensitivity C-reactive protein (hsCRP) and Interleukin-6 (IL-6)], endothelial activation [soluble Vascular Cell Adhesion Molecule-1 (sVCAM-1), soluble Intercellular Adhesion Molecule-1 (sICAM-1) and E-selectin)] and oxidative stress [F2-Isoprostanes, oxidized Low Density Lipoprotein (ox-LDL) and Malondialdehyde (MDA)]. RESULTS Subjects with low HDL-c had greater concentrations of inflammation, endothelial activation and oxidative stress biomarkers compared to controls. There were negative correlations between HDL-c concentration and biomarkers of inflammation (IL-6, p = 0.02), endothelial activation (sVCAM-1 and E-selectin, p = 0.029 and 0.002, respectively), and oxidative stress (MDA and F2-isoprostane, p = 0.036 and <0.0001, respectively). Multiple linear regression analysis showed HDL-c as an independent predictor of IL-6 (p = 0.02) and sVCAM-1 (p<0.03) after correcting for various confounding factors. CONCLUSION Low serum HDL-c concentration is strongly correlated with enhanced status of inflammation, endothelial activation and oxidative stress. It is also an independent predictor for enhanced inflammation and endothelial activation, which are pivotal in the pathogenesis of atherosclerosis and atherosclerosis-related complications.
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Affiliation(s)
- Wan Nor Hanis Wan Ahmad
- Centre for Pathology Diagnostic and Research Laboratories (CPDRL), UniversitiTeknologi MARA (UiTM), Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
| | - Farah Sakri
- Centre for Pathology Diagnostic and Research Laboratories (CPDRL), UniversitiTeknologi MARA (UiTM), Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
| | - Atiqah Mokhsin
- Centre for Pathology Diagnostic and Research Laboratories (CPDRL), UniversitiTeknologi MARA (UiTM), Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
| | - Thuhairah Rahman
- Centre for Pathology Diagnostic and Research Laboratories (CPDRL), UniversitiTeknologi MARA (UiTM), Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
- Cluster for Pathology and Laboratory Medicine, UniversitiTeknologi MARA (UiTM), Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
| | - Nadzimah Mohd Nasir
- Centre for Pathology Diagnostic and Research Laboratories (CPDRL), UniversitiTeknologi MARA (UiTM), Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
- Cluster for Pathology and Laboratory Medicine, UniversitiTeknologi MARA (UiTM), Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
| | - Suraya Abdul-Razak
- Primary Care Medicine Discipline, UniversitiTeknologi MARA (UiTM), Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
| | - Mazapuspavina Md Yasin
- Primary Care Medicine Discipline, UniversitiTeknologi MARA (UiTM), Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
| | - Aletza Mohd Ismail
- Centre for Pathology Diagnostic and Research Laboratories (CPDRL), UniversitiTeknologi MARA (UiTM), Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
- Cluster for Pathology and Laboratory Medicine, UniversitiTeknologi MARA (UiTM), Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
| | - Zaliha Ismail
- Discipline of Population Health and Preventive Medicine, Faculty of Medicine, UniversitiTeknologi MARA (UiTM), Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
| | - Hapizah Nawawi
- Centre for Pathology Diagnostic and Research Laboratories (CPDRL), UniversitiTeknologi MARA (UiTM), Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
- Cluster for Pathology and Laboratory Medicine, UniversitiTeknologi MARA (UiTM), Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
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10
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Perrotta I, Perrotta E, Sesti S, Cassese M, Mazzulla S. MnSOD expression in human atherosclerotic plaques: an immunohistochemical and ultrastructural study. Cardiovasc Pathol 2013; 22:428-37. [DOI: 10.1016/j.carpath.2013.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 02/26/2013] [Accepted: 03/03/2013] [Indexed: 11/25/2022] Open
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11
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Liu Y, Meyer C, Xu C, Weng H, Hellerbrand C, ten Dijke P, Dooley S. Animal models of chronic liver diseases. Am J Physiol Gastrointest Liver Physiol 2013; 304:G449-68. [PMID: 23275613 DOI: 10.1152/ajpgi.00199.2012] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Chronic liver diseases are frequent and potentially life threatening for humans. The underlying etiologies are diverse, ranging from viral infections, autoimmune disorders, and intoxications (including alcohol abuse) to imbalanced diets. Although at early stages of disease the liver regenerates in the absence of the insult, advanced stages cannot be healed and may require organ transplantation. A better understanding of underlying mechanisms is mandatory for the design of new drugs to be used in clinic. Therefore, rodent models are being developed to mimic human liver disease. However, no model to date can completely recapitulate the "corresponding" human disorder. Limiting factors are the time frame required in humans to establish a certain liver disease and the fact that rodents possess a distinct immune system compared with humans and have different metabolic rates affecting liver homeostasis. These features account for the difficulties in developing adequate rodent models for studying disease progression and for testing new pharmaceuticals to be translated into the clinic. Nevertheless, traditional and new promising animal models that mimic certain attributes of chronic liver diseases are established and being used to deepen our understanding in the underlying mechanisms of distinct liver diseases. This review aims at providing a comprehensive overview of recent advances in animal models recapitulating different features and etiologies of human liver diseases.
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Affiliation(s)
- Yan Liu
- Department of Medicine II, Section Molecular Hepatology-Alcohol Associated Diseases, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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12
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Zhao R, Xie X, Shen GX. Effects of glycated low-density lipoprotein on cell viability, proliferation, and growth factors of mouse embryo fibroblasts. Can J Physiol Pharmacol 2013; 91:64-70. [PMID: 23369077 DOI: 10.1139/cjpp-2012-0234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The predominant cause of death in diabetic patients is atherosclerotic coronary artery disease (CAD). Major gross cellular changes in the vascular wall of persons with CAD include endothelial injury and foam cell formation, as well as smooth muscle cell and fibroblast proliferation. This study examined the effects of glycated low density lipoprotein (glyLDL), a biochemical marker of diabetes, on cell viability, proliferation, and the expression of multiple growth factors in mouse embryo fibroblasts (MEF). The results demonstrated that exposure to ≥150 μg/mL of glyLDL for 24 h or 100 μg/mL of glyLDL for ≥48 h either significantly reduced cell viability or increased DNA fragmentation in MEF. GlyLDL treatment (25-100 μg/mL for up to 12 h) significantly increased the abundance of proliferating cell nuclear antigen (PCNA) and achieved a peak after 4 h exposure to glyLDL. Abundances of fibroblast growth factor-basic (FGF), transforming growth factor-β (TGF), and platelet-derived growth factor-A (PDGF) in MEF reached maximal levels after 2 h exposure to 50 μg/mL of glyLDL. The maximal increase of vascular endothelial growth factor (VEGF) was detected in MEF after 4 h of exposure to 50 μg/mL of glyLDL. Inhibitors for FGF (AZD4547), VEGF, or PDGF receptors (Axitinib), but not that for TGF receptor (LY364947), significantly decreased the abundance of (PCNA) in endothelial cells. The findings suggest that early exposure to a low dosage of glyLDL transiently increases the proliferation of MEF through the upregulation of FGF, VEGF, and (or) PDGF, and prolonged exposure to high concentrations of glyLDL reduced cell viability, which possibly accelerates atherogenesis under diabetic condition.
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Affiliation(s)
- Ruozhi Zhao
- Department of Internal Medicine, Health Sciences Centre, University of Manitoba, 820 Sherbrooke Street, Winnipeg, MB R3T 2N2, Canada
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13
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Yimin, Furumaki H, Matsuoka S, Sakurai T, Kohanawa M, Zhao S, Kuge Y, Tamaki N, Chiba H. A novel murine model for non-alcoholic steatohepatitis developed by combination of a high-fat diet and oxidized low-density lipoprotein. J Transl Med 2012; 92:265-81. [PMID: 22064320 DOI: 10.1038/labinvest.2011.159] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Non-alcoholic steatohepatitis (NASH) is the hepatic manifestation of metabolic syndrome that is characterized by steatosis, inflammation, and fibrosis, and may progress to cirrhosis and carcinoma. To investigate its pathogenic processes, we established a novel murine model for NASH by combination of a high-fat diet (HFD) and oxidized low-density lipoprotein (oxLDL). Mice that received HFD for 23 weeks showed hepatic steatosis, slight fibrosis, and a high level of lipid peroxidation compared with a regular diet (RD)-fed mice. Hepatic injury and elevated tumor necrosis factor (TNF)-α mRNA expression were also detected in these mice. Moreover, oxLDL administration to HFD-fed mice during weeks 21-23 not only aggravated hepatic steatosis, fibrosis, and lipid metabolism, but also resulted in intense inflammation, including severe hepatic injury and inflammatory cell infiltration, which are the typical histological features of NASH. Inflammation was accompanied by increased gene expression of TNF-α and interleukin (IL)-6. Additionally, the livers of RD-fed animals treated with oxLDL during weeks 21-23 were characterized by foamy macrophages and inflammatory cell infiltration along with an elevated IL-6 mRNA level. These results suggest that an increased oxidative state, including HFD-induced intracellular lipid peroxidation and its extracellular source from oxLDL, is the actual trigger for hepatic inflammation in which liver injury is mediated by TNF-α and inflammatory cell accumulation is dependent on IL-6. HFD and oxLDL also induced insulin resistance in mice; additionally, oxLDL downregulated insulin secretion. In this model, CD36 overexpression was observed in the hepatocytes of HFD-fed mice and those treated with HFD and oxLDL, and in the hepatic macrophages of RD-fed mice immediately after oxLDL treatment. In vitro experiments indicated a rapid and transient elevation of CD36 on macrophage plasma membrane in response to oxLDL. Our findings demonstrate that CD36 expressed on hepatocytes and hepatic macrophages mediates the pathophysiology of NASH.
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Affiliation(s)
- Yimin
- Department of Advanced Medicine, Graduate School of Medicine, Hokkaido University, Sapporo, Japan
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Mazière C, Trécherel E, Ausseil J, Louandre C, Mazière JC. Oxidized low density lipoprotein induces cyclin a synthesis. Involvement of ERK, JNK and NFkappaB. Atherosclerosis 2011; 218:308-13. [DOI: 10.1016/j.atherosclerosis.2011.06.034] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 06/16/2011] [Accepted: 06/16/2011] [Indexed: 01/31/2023]
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Abstract
Proline is metabolized by its own specialized enzymes with their own tissue and subcellular localizations and mechanisms of regulation. The central enzyme in this metabolic system is proline oxidase, a flavin adenine dinucleotide-containing enzyme which is tightly bound to mitochondrial inner membranes. The electrons from proline can be used to generate ATP or can directly reduce oxygen to form superoxide. Although proline may be derived from the diet and biosynthesized endogenously, an important source in the microenvironment is from degradation of extracellular matrix by matrix metalloproteinases. Previous studies showed that proline oxidase is a p53-induced gene and its overexpression can initiate proline-dependent apoptosis by both intrinsic and extrinsic pathways. Another important factor regulating proline oxidase is peroxisome proliferator activated receptor gamma (PPARγ). Importantly, in several cancer cells, proline oxidase may be an important mediator of the PPARγ-stimulated generation of ROS and induction of apoptosis. Knockdown of proline oxidase expression by antisense RNA markedly decreased these PPARγ-stimulated effects. These findings suggest an important role in the proposed antitumor effects of PPARγ. Moreover, it is possible that proline oxidase may contribute to the other metabolic effects of PPARγ.
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Zabirnyk O, Liu W, Khalil S, Sharma A, Phang JM. Oxidized low-density lipoproteins upregulate proline oxidase to initiate ROS-dependent autophagy. Carcinogenesis 2009; 31:446-54. [PMID: 19942609 PMCID: PMC2832543 DOI: 10.1093/carcin/bgp299] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Epidemiological studies showed that high levels of oxidized low-density lipoproteins (oxLDLs) are associated with increased cancer risk. We examined the direct effect of physiologic concentrations oxLDL on cancer cells. OxLDLs were cytotoxic and activate both apoptosis and autophagy. OxLDLs have ligands for peroxisome proliferator-activated receptor gamma and upregulated proline oxidase (POX) through this nuclear receptor. We identified 7-ketocholesterol (7KC) as a main component responsible for the latter. To elucidate the role of POX in oxLDL-mediated cytotoxicity, we knocked down POX via small interfering RNA and found that this (i) further reduced viability of cancer cells treated with oxLDL; (ii) decreased oxLDL-associated reactive oxygen species generation; (iii) decreased autophagy measured via beclin-1 protein level and light-chain 3 protein (LC3)-I into LC3-II conversion. Using POX-expressing cell model, we established that single POX overexpression was sufficient to activate autophagy. Thus, it led to autophagosomes accumulation and increased conversion of LC3-I into LC3-II. Moreover, beclin-1 gene expression was directly dependent on POX catalytic activity, namely the generation of POX-dependent superoxide. We conclude that POX is critical in the cellular response to the noxious effects of oxLDL by activating protective autophagy.
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Affiliation(s)
- Olga Zabirnyk
- Metabolism and Cancer Susceptibility Section, Laboratory of Comparative Carcinogenesis, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702-1201, USA
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Mazière C, Louvet L, Gomila C, Kamel S, Massy Z, Mazière JC. Oxidized low density lipoprotein decreases Rankl-induced differentiation of osteoclasts by inhibition of Rankl signaling. J Cell Physiol 2009; 221:572-8. [PMID: 19725047 DOI: 10.1002/jcp.21886] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The role of OxLDL in the generation and progression of atherosclerosis is well admitted. In addition, it is well known that atherosclerosis is often accompanied by perturbations in bone remodeling, resulting in osteoporosis. In the current studies, the effect of Cu(2+)-oxidized LDL (OxLDL) on RANKL-induced RAW264.7 mouse monocytes-macrophages differentiation to osteoclasts and on RANKL signaling pathway was investigated. OxLDL, within the range of 10-50 microg protein/ml, prevented RANKL-induced generation of multinucleated osteoclast-like cells and RANKL-induced tartrate resistant acid phosphatase (TRAP) activity. OxLDL also prevented the RANKL-induced phosphorylation of ERK, p38 and JNK kinases, together with the RANKL-induced DNA binding activities of NFkappaB and NFAT transcription factors. Concomitantly, OxLDL enhanced RANKL-induced generation of reactive oxygen species in a dose-dependent manner. The antioxidant glutathione (GSH) prevented whereas the prooxidant compound buthionine-sulfoximine (BSO) enhanced the effect of OxLDL on RANKL-induced oxidative stress and RANKL-induced differentiation. Finally, OxLDL also prevented RANKL-induced TRAP activity and RANKL-induced bone resorbing activity of human peripheral blood mononuclear cells. These results demonstrate that OxLDL, by generation of an intracellular oxidative stress, prevents the differentiation of osteoclasts by inhibition of RANKL signaling pathway. This might be related to the fact that atherosclerosis is accompanied by perturbations in bone and vascular remodeling, leading to osteoporosis and vascular calcification.
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Mazière C, Mazière JC. Activation of transcription factors and gene expression by oxidized low-density lipoprotein. Free Radic Biol Med 2009; 46:127-37. [PMID: 18996472 DOI: 10.1016/j.freeradbiomed.2008.10.024] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2008] [Revised: 06/26/2008] [Accepted: 10/01/2008] [Indexed: 11/25/2022]
Abstract
It is well recognized that oxidized LDL (OxLDL) plays a crucial role in the initiation and progression of atherosclerosis. Many biological effects of OxLDL are mediated through signaling pathways, especially via the activation of transcription factors, which in turn stimulate the expression of genes involved in the inflammatory and oxidative stress response or in cell cycle regulation. In this review, we will discuss the various transcription factors activated by OxLDL, the studied cell types, the active compounds of the OxLDL particle, and the downstream genes when identified. Identification of the transcription factors and some of the downstream genes regulated by OxLDL has helped us understand the molecular mechanism involved in generation of the atherosclerotic plaque.
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Affiliation(s)
- Cécile Mazière
- Biochemistry Laboratory, North Hospital, University of Picardie-Jules Verne, and INSERM, ERI 12, Amiens F-80000, France.
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van Hooland S, Boey O, Van Der Niepen P, Van Den Branden C, Verbeelen D. Effect of Short-Term Rosiglitazone Therapy in Peritoneal Dialysis Patients. ARCH ESP UROL 2009. [DOI: 10.1177/089686080902900115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Simon van Hooland
- Department of Nephrology Universitair Ziekenhuis Brussel, Brussels, Belgium
| | - Olivier Boey
- Department of Nephrology Universitair Ziekenhuis Brussel, Brussels, Belgium
| | | | | | - Dierik Verbeelen
- Department of Nephrology Universitair Ziekenhuis Brussel, Brussels, Belgium
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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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Nishikiori R, Nomura Y, Sawajiri M, Masuki K, Hirata I, Okazaki M. Influence of chlorine dioxide on cell death and cell cycle of human gingival fibroblasts. J Dent 2008; 36:993-8. [DOI: 10.1016/j.jdent.2008.08.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Revised: 08/07/2008] [Accepted: 08/16/2008] [Indexed: 12/31/2022] Open
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Göçmen AY, Sahin E, Semiz E, Gümuşlü S. Is elevated serum ceruloplasmin level associated with increased risk of coronary artery disease? Can J Cardiol 2008; 24:209-12. [PMID: 18340391 DOI: 10.1016/s0828-282x(08)70586-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND An imbalance between the lipid peroxidation process and antioxidative protection is associated with the pathophysiology of coronary artery disease (CAD). The authors aimed to determine the relationship between the contributors of antioxidant protection, such as paraoxonase-1 (PON1) activity, albumin, vitamin C and ceruloplasmin (CP) levels, and lipid peroxidation indicators. METHODS In the present study, the activity of PON1 was measured, together with serum concentrations of a variety of lipid constituents, albumin, vitamin C and CP levels, and lipid peroxidation indicators (conjugated dienes [CDs] and thiobarbituric acid-reactive substances [TBARS]). Data were gathered from 26 nondiabetic, angiographically proven, Turkish CAD patients and 26 healthy controls living in the Antalya region (Turkey). RESULTS CAD patients had significantly lower PON1 activity, high-density lipoprotein cholesterol, vitamin C and albumin concentrations, and higher CP, CD and TBARS concentrations than the controls. In the entire study population (n=52), serum CP levels were positively correlated with TBARS and CD levels, and negatively correlated with albumin and vitamin C levels, as well as with PON1 activity. On multiple logistic regression analysis, risk factors associated with CAD included high CP and low albumin levels. CONCLUSIONS CAD patients and controls were matched for age and sex, and high CP and low albumin levels were found to be independent risk factors for CAD. The present data gathered from the study group living in the Antalya region verifies that in CAD patients, CP impairs the oxidant-antioxidant balance in favour of the oxidants.
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Mehendale S, Aung H, Wang CZ, Tong R, Foo A, Xie JT, Yuan CS. Scutellaria baicalensis and a constituent flavonoid, baicalein, attenuate ritonavir-induced gastrointestinal side-effects. J Pharm Pharmacol 2007; 59:1567-72. [PMID: 17976269 PMCID: PMC2676851 DOI: 10.1211/jpp.59.11.0015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Ritonavir, a protease inhibitor drug, is commonly used in AIDS therapy. As with other chemotherapeutic drugs that cause gastrointestinal adverse effects, ritonavir treatment is associated with significant nausea and vomiting. This study investigated whether Scutellaria baicalensis, and its active flavonoid constituent, baicalein, attenuate the gastrointestinal effects of ritonavir. The effects of herb administration were evaluated in ritonavir-treated rats using a rat pica model, which simulates nausea and vomiting in humans. The effects of herb administration on gastric emptying in rats were also measured. Ritonavir treatment resulted in increased kaolin intake or severe pica, the intensity of which was reduced significantly with S. baicalensis administration (1 mg kg(-1); P<0.05). High-performance liquid chromatography analysis of S. baicalensis showed the presence of an extremely potent flavonoid constituent, baicalein. The study aimed to determine if baicalein contributed to the anti-pica effect of the extract. It was observed that baicalein dose-dependently decreased pica in ritonavir-treated rats (P<0.001). In addition to inducing pica, ritonavir also significantly delayed gastric emptying, which could contribute to ritonavir-induced gastrointestinal dysfunction. When S. baicalensis extract was administered to ritonavir-treated rats the delayed gastric emptying was significantly attenuated (P<0.05). The results suggest that S. baicalensis and the constituent baicalein reduce the gastrointestinal dysfunction caused by ritonavir. It is concluded that S. baicalensis may potentially have a role to play in reducing drug-induced adverse effects.
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Affiliation(s)
- Sangeeta Mehendale
- Tang Center for Herbal Medicine Research, The Pritzker School of Medicine, University of Chicago, Chicago, IL 60637, USA
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Lu LS, Hung LM, Liao CH, Wu CC, Su MJ. Effects of rosiglitazone on native low-density-lipoprotein-induced respiratory burst in circulating monocytes and on the leukocyte-endothelial interaction in cholesterol-fed rats. Naunyn Schmiedebergs Arch Pharmacol 2007; 375:251-60. [PMID: 17450350 DOI: 10.1007/s00210-007-0159-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2006] [Accepted: 03/15/2007] [Indexed: 10/23/2022]
Abstract
Low-density lipoprotein (LDL) has been implicated in the initiation and progression of atherosclerotic vascular disease. But whether LDL can elicit similar effects in the microcirculation remain unexplored. To approach this issue, the hypothesis that LDL promotes oxidative stress in monocytes and results in microvascular inflammation was tested. Native LDL was capable of stimulating respiratory burst in rat monocytes, and this was blocked by BAPTA, cytochalasin B, apocynin, and diphenyliodonium. In monocytes from rats on a high-cholesterol (4%) diet, increased intracellular calcium, actin polymerization, respiratory burst, and surface CD18 expression were found. Concurrently, leukocyte-endothelial interaction was enhanced in the cremaster microcirculation. Rosiglitazone, an insulin-sensitizing agent with antiinflammatory properties, was found to suppress native-LDL-induced actin polymerization and respiratory burst in monocytes. It also improved leukocytes activation and leukocyte-endothelial interaction due to the high cholesterol intake. Hence, native LDL stimulation of monocytes contributed to hypercholesterolemia-associated microvascular inflammation, which could be treated by rosiglitazone.
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Affiliation(s)
- Long Sheng Lu
- Graduate Institute of Pharmacology, National Taiwan University College of Medicine, Taipei, Taiwan
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Ryan L, O'Callaghan YC, O'Brien NM. The role of the mitochondria in apoptosis induced by 7β-hydroxycholesterol and cholesterol-5β,6β-epoxide. Br J Nutr 2007; 94:519-25. [PMID: 16197575 DOI: 10.1079/bjn20051524] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Oxysterols are oxygenated derivatives of cholesterol that may be formed endogenously or absorbed from the diet. Significant amounts of oxysterols have frequently been identified in foods of animal origin, in particular highly processed foods. To date, oxysterols have been shown to possess diverse biological activities; however, recent attention has focused on their potential role in the development of atherosclerosis. Oxysterols have been reported to induce apoptosis in cells of the arterial wall, a primary process in the development of atheroma. The aim of the present study was to identify the role of the mitochondria in the apoptotic pathways induced by the oxysterols 7β-hydroxycholesterol (7β-OH) and cholesterol-5β,6β-epoxide (β-epoxide) in U937 cells. To this end, we investigated the effects of these oxysterols on mitochondrial membrane potential, caspase-8 activity, the mitochondrial permeability transition pore and cytochromecrelease. 7β-OH-induced apoptosis was associated with a loss in mitochondrial membrane potential after 2 h, accompanied by cytochromecrelease from the mitochondria into the cytosol after 16 h. Pre-treatment with a range of inhibitors of the mitochondrial permeability transition pore protected against 7β-OH-induced cell death. In contrast, β-epoxide induced a slight increase in caspase-8 activity but had no effect on mitochondrial membrane potential or cytochromecrelease. The present results confirm that 7β-OH-induced apoptosis occurs via the mitochondrial pathway and highlights differences in the apoptotic pathways induced by 7β-OH and β-epoxide in U937 cells.
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Affiliation(s)
- Lisa Ryan
- Department of Food and Nutritional Sciences, University College Cork, Republic of Ireland
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Chen J, Mehta JL. Interaction of oxidized low-density lipoprotein and the renin-angiotensin system in coronary artery disease. Curr Hypertens Rep 2006; 8:139-43. [PMID: 16672147 DOI: 10.1007/s11906-006-0010-2] [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: 10/23/2022]
Abstract
Hyperlipidemia and hypertension are frequently observed in patients with coronary artery disease. It has been proposed that an interaction between low-density lipoprotein, especially its oxidized form (ox-LDL), and renin-angiotensin system (RAS) activation is a major determinant of atherogenesis. Ox-LDL accumulation in the blood vessels enhances the expression and activation of RAS components; on the other hand, activation of RAS stimulates the accumulation of LDL and its oxidation into ox-LDL in the blood vessels. Individually ox-LDL and RAS activation induce oxidative stress and inflammatory cascade, whereas their combination exerts a synergistic effect. This concept of cross-talk between ox-LDL/hyperlipidemia and RAS activation has been proven in laboratory animals. Clinical trials also suggest that blockade of hyperlipidemia and RAS may have a synergistic salutary effect on the outcome of patients with hypertension and/or manifestations of atherosclerosis. This concept needs to be evaluated further in large clinical studies.
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Affiliation(s)
- Jiawei Chen
- Division of Cardiovascular Medicine, University of Arkansas for Medical Sciences, 4301 W. Markham Street, Slot 532, Little Rock, AR 72205, USA
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Shimozawa M, Naito Y, Manabe H, Uchiyama K, Kuroda M, Katada K, Yoshida N, Yoshikawa T. 7-Ketocholesterol enhances the expression of adhesion molecules on human aortic endothelial cells by increasing the production of reactive oxygen species. Redox Rep 2005; 9:370-5. [PMID: 15720835 DOI: 10.1179/135100004225006902] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The aim of the present study was to assess the expression of intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), monocytic adhesion of human aortic endothelial cells (HAECs), and the production of intracellular reactive oxygen species (ROS), when HAECs were stimulated by 7-ketocholesterol. 7-ketocholesterol enhances surface expression of ICAM-1 and VCAM-1 as determined by EIA, induces their mRNA expression by RT-PCR, and stimulates adhesiveness of HAECs to U937 monocytic cells. We confirmed up-regulation of ROS production of HAECs treated with 7-ketocholesterol. Although the surface expression of ICAM-1 and VCAM-1 on HAECs treated with 7-ketocholesterol increased in a time-dependent manner, alpha-tocopherol inhibited this increase of the surface expression of ICAM-1 and VCAM-1. In the monocytic adhesion assay, adhesion of U937 to HAECs treated with 7-ketocholesterol was enhanced, but monoclonal anti-ICAM-1 and VCAM-1 antibodies reduced the endothelial adhesiveness. In conclusion, this study suggests that the endothelial adhesiveness to monocytic cells that was increased by 7-ketocholesterol was associated with enhanced expression of ICAM-1 and VCAM-1 mediated by ROS production.
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Affiliation(s)
- Makoto Shimozawa
- Department of Inflammation and Immunology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
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Farhangkhoee H, Khan ZA, Barbin Y, Chakrabarti S. Glucose-induced up-regulation of CD36 mediates oxidative stress and microvascular endothelial cell dysfunction. Diabetologia 2005; 48:1401-10. [PMID: 15915335 DOI: 10.1007/s00125-005-1801-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2004] [Accepted: 02/26/2005] [Indexed: 02/02/2023]
Abstract
AIMS/HYPOTHESIS Hyperglycaemia-induced oxidative stress is implicated in the pathogenesis of chronic diabetic complications. Glucose-mediated oxidation of LDL may result in increased oxidative stress and vascular endothelial cell dysfunction via interaction with a cell surface scavenger receptor, CD36. In this study, we investigated the role of CD36 in cultured microvascular endothelial cells (MVECs) and in the heart by using an animal model of chronic diabetes. METHODS Cultured MVECs were subjected to varying glucose concentrations and assayed for alteration in CD36 gene expression and protein levels. To assess for oxidised LDL (ox-LDL) uptake, MVECs exposed to low and high glucose were treated with ox-LDL (80 microg/ml), a ligand for CD36. Haem oxygenase-1 (HO-1) and endothelin-1 (ET-1) induction, as well as oxidative stress were determined. The role of glucose-induced CD36 alteration in ox-LDL uptake was also assayed following post-transcriptional CD36 gene silencing. For in vivo studies, CD36 mRNA and oxidative DNA and protein damage were measured in heart tissues of 1-month-old diabetic Sprague-Dawley rats. RESULTS We found that glucose increased CD36 mRNA and protein levels in MVECs. High levels of glucose also augmented ox-LDL uptake, in association with increasing HO-1 and ET-1 mRNA levels. CD36 gene silencing prevented glucose-induced CD36 alteration, reduced ox-LDL uptake, and prevented HO-1 and ET-1 up-regulation. Similar to in vitro studies, diabetic heart tissues exhibited increased CD36 mRNA levels and increased oxidative DNA and protein damage. CONCLUSIONS/INTERPRETATION Our results provide evidence that up-regulation of CD36 may have a role in increasing oxidative stress in MVECs and the heart in chronic diabetes.
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Affiliation(s)
- H Farhangkhoee
- Department of Pathology, University of Western Ontario, London, ON, N6A 5C1, Canada
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Mazière C, Morlière P, Massy Z, Kamel S, Louandre C, Conte MA, Mazière JC. Oxidized low-density lipoprotein elicits an intracellular calcium rise and increases the binding activity of the transcription factor NFAT. Free Radic Biol Med 2005; 38:472-80. [PMID: 15649649 DOI: 10.1016/j.freeradbiomed.2004.10.028] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2004] [Revised: 05/27/2004] [Accepted: 10/22/2004] [Indexed: 11/22/2022]
Abstract
Oxidized low-density lipoprotein (OxLDL) plays a key role in the generation and progression of atherosclerosis, which might be considered as an inflammatory disease. The transcription factor NFAT(Nuclear Factor of Activated T cells) plays an important role in the control of cytokine genes involved in the inflammatory response. The effect of copper-oxidized LDL (CuLDL) and monocyte-oxidized LDL (M-LDL) on the DNA-binding activity of NFAT was investigated in the T lymphocyte cell line Jurkat. Both OxLDL increased NFAT-binding activity in a dose-dependent manner within the range of 25-75 microg LDL protein/ml. This effect reached a maximum 1 h after the introduction of OxLDL in the medium. CuLDL and M-LDL both induce an intracellular calcium rise in a dose-dependent manner, with a maximum increase 15 min after the addition of OxLDL. The CuLDL-induced NFAT-binding activity was abolished in the presence of the calcium chelator EGTA or of the intracellular calcium trapping drug BAPTA, further indicating the involvement of calcium ions in the effect of OxLDL. In addition, cyclosporin A and FK 506, two inhibitors of calcineurin, a calcium-dependent phosphatase upstream of NFAT, also prevented the CuLDL-induced NFAT-binding activity, thus demonstrating the role of calcineurin. CuLDL and M-LDL also induced an increase in the intracellular level of reactive oxygen species (ROS), which reached a maximum 30 min after the addition of OxLDL. Finally, a pretreatment of cells with the antioxidant vitamin E blocked the CuLDL-induced increase in reactive oxygen species, in intracellular calcium rise and the CuLDL-induced NFAT-binding activity. The lipid extract of CuLDL, which includes the lipid peroxidation products, reproduced the effect of the CuLDL itself. These results suggest that the effect of OxLDL on NFAT is initiated by an oxidative stress, which then in turn activates the calcium-calcineurin signaling pathway of the transcription factor NFAT. This effect of OxLDL might be involved in the inflammatory process observed in atherosclerotic lesions.
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Affiliation(s)
- Cécile Mazière
- Laboratoire de Biochimie, EA 2087 and EA 2086, CHU Amiens, Hôpital Nord, Place Victor Pauchet, 80054 Amiens Cedex 1, France.
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Larbi A, Khalil A, Douziech N, Guérard KP, Fülöp T. Oxidized low-density lipoproteins induced inflammatory process during atherogenesis with aging. Radiat Phys Chem Oxf Engl 1993 2005. [DOI: 10.1016/j.radphyschem.2004.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Sacktor N, Haughey N, Cutler R, Tamara A, Turchan J, Pardo C, Vargas D, Nath A. Novel markers of oxidative stress in actively progressive HIV dementia. J Neuroimmunol 2004; 157:176-84. [PMID: 15579295 DOI: 10.1016/j.jneuroim.2004.08.037] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2004] [Indexed: 10/26/2022]
Abstract
Oxidative stress leads to the production of reactive oxygen species that can attack lipid membranes resulting in cellular dysfunction and death. Cellular redox state is closely linked to ceramide, sphingomyelin, and 4-hydroxynonenal (HNE) levels. We describe data showing increased levels of these oxidative stress markers in HIV encephalitis. In addition, actively progressing HIV dementia is associated with increases in HNE and ceramide, while inactive HIV dementia is associated with increases in sphingomyelin. These markers may be useful for distinguishing between different clinical phenotypes of HIV dementia.
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Affiliation(s)
- Ned Sacktor
- Department of Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD 21287, USA.
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Mazière C, Morlière P, Santus R, Marcheux V, Louandre C, Conte MA, Mazière JC. Inhibition of insulin signaling by oxidized low density lipoprotein. Protective effect of the antioxidant Vitamin E. Atherosclerosis 2004; 175:23-30. [PMID: 15186943 DOI: 10.1016/j.atherosclerosis.2004.02.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2003] [Revised: 02/02/2004] [Accepted: 02/13/2004] [Indexed: 12/26/2022]
Abstract
Oxidative stress is involved in several pathological conditions, including diabetes. Reactive oxygen species (ROS) have been demonstrated to act as second messengers for several hormones and cytokines, including insulin (INS). The effect of Cu(2+)-oxidized LDL (CuLDL) on INS-induced generation of ROS and on INS signaling was investigated on cultured human fibroblasts. Intracellular ROS generation was observed either in CuLDL- or in INS-treated cells. Moreover, CuLDL and INS had an additive effect on ROS formation in human fibroblasts. CuLDL by itself increased the phosphorylation of ERK without affecting the PKB/Akt phosphorylation. CuLDL also stimulated the DNA binding activities of the transcription factors AP1 and NFkappaB. However, CuLDL dose-dependently prevented the INS-signaling pathway, by inhibiting the INS-induced phosphorylation of the signaling kinases ERK and PKB/Akt and the INS-induced activation of the transcription factors AP1 and NFkappaB. Finally, the lipophilic antioxidant Vitamin E (Vit E) partially restored all the studied signaling events initiated by INS and impaired after pretreatment with CuLDL. These studies demonstrate that the oxidative stress generated by CuLDL has a negative effect on the INS-signaling pathway, independently of the INS-induced generation of ROS. Thus, oxidized LDL might be involved not only in atherosclerosis, as it is commonly admitted, but also in the INS-resistance observed in type 2 diabetes mellitus.
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Affiliation(s)
- Cécile Mazière
- Laboratoire de Biochimie EA 2087, CHU Amiens, Université de Picardie Jules Verne, Hôpital Nord, Place Victor Pauchet, 80054 Amiens Cedex 1, France.
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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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Haughey NJ, Cutler RG, Tamara A, McArthur JC, Vargas DL, Pardo CA, Turchan J, Nath A, Mattson MP. Perturbation of sphingolipid metabolism and ceramide production in HIV-dementia. Ann Neurol 2004; 55:257-67. [PMID: 14755730 DOI: 10.1002/ana.10828] [Citation(s) in RCA: 199] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Infection by the human immunodeficiency virus type 1 (HIV-1) often results in neurological dysfunction including HIV dementia (HIVD). Alterations in cytokine and redox balance are thought to play important roles in the pathogenesis of HIVD, but the specific mechanisms underlying neuronal dysfunction and death are unknown. Activation of cytokine receptors and oxidative stress can induce the production of ceramide from membrane sphingomyelin, and recent findings suggest that ceramide is an important mediator of a form of programmed cell death called apoptosis. We now report that levels of ceramide, sphingomyelin, and hydroxynonenal (HNE) are significantly increased in brain tissues and cerebrospinal fluid of HIVD patients. Exposure of cultured neurons to the neurotoxic HIV proteins gp120 and Tat resulted in increased cellular levels of sphingomyelin, ceramide, and HNE. The ceramide precursor palmitoyl-CoA sensitized neurons to Tat and gp120 toxicity, whereas an inhibitor of ceramide production reduced Tat and gp120-induced increases of ceramide and HNE and protected the neurons from Tat and gp120-induced death. These results suggest that HIV-1 infection may promote a lipid imbalance in neural cells, resulting in an overproduction of ceramide and consequent cellular dysfunction and death.
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Affiliation(s)
- Norman J Haughey
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
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Shatrov VA, Brüne B. Induced expression of manganese superoxide dismutase by non-toxic concentrations of oxidized low-density lipoprotein (oxLDL) protects against oxLDL-mediated cytotoxicity. Biochem J 2003; 374:505-11. [PMID: 12826016 PMCID: PMC1223623 DOI: 10.1042/bj20030420] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2003] [Revised: 06/11/2003] [Accepted: 06/25/2003] [Indexed: 01/10/2023]
Abstract
Oxidized low-density lipoprotein (oxLDL) affects macrophages and plays a critical role in the development of atherosclerosis. In the present paper, we demonstrate that high concentrations of oxLDL provoked apoptosis of human Mono-Mac-6 cells, which was blocked by diphenylene-iodonium (DPI), an inhibitor of flavin-containing enzymes, such as NADPH oxidase, suggesting the involvement of reactive oxygen species (ROS). Importantly, pre-treatment of cells with low concentrations of oxLDL prevented apoptosis in response to high concentrations of oxLDL by up-regulating manganese superoxide dismutase (MnSOD). DPI prevented expression of MnSOD by oxLDL, whereas inhibitors of cytochrome P450 (methoxalen) or xanthine oxidase (allopurinol) did not, thus pointing to a role of NADPH-oxidase-derived ROS in oxLDL-induced MnSOD expression. Transfection of cells with MnSOD antisense, but not scrambled antisense, oligonucleotides significantly attenuated oxLDL-mediated MnSOD expression and hindered cytoprotective effects of non-toxic oxLDL concentrations. Our findings suggest that up-regulation of MnSOD by low concentrations of oxLDL is critical for protection towards oxLDL-mediated cytotoxicity.
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Affiliation(s)
- Vladimir A Shatrov
- Department of Cell Biology, Faculty of Biology, University of Kaiserslautern, Erwin-Schroedinger-Strasse, 67663 Kaiserslautern, Germany
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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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Kitatani K, Nemoto M, Akiba S, Sato T. Stimulation by de novo-synthesized ceramide of phospholipase A(2)-dependent cholesterol esterification promoted by the uptake of oxidized low-density lipoprotein in macrophages. Cell Signal 2002; 14:695-701. [PMID: 12020770 DOI: 10.1016/s0898-6568(02)00014-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The involvement of cytosolic phospholipase A(2) (cPLA(2)) and ceramide in the accumulation of cholesteryl ester induced by the uptake of oxidized low-density lipoproteins (oxLDL) in macrophages was investigated. Uptake of oxLDL by [(3)H]oleic acid-labeled macrophages stimulated the formation of cholesteryl oleate, and this process was completely inhibited by a cPLA(2) inhibitor. Under the conditions, a time-dependent increase in ceramide was observed, while sphingomyelin levels were unaffected. The production of ceramide was completely inhibited by fumonisin B1, an inhibitor of the de novo synthesis of ceramide, and oxLDL-induced cholesteryl oleate formation was inhibited partially. Treatment of the cells with sphingomyelinase accelerated the formation of cholesteryl ester. Furthermore, sphingomyelinase or cell-permeable ceramide induced the release of oleic acid, and this was inhibited by a cPLA(2) inhibitor. These results suggest that activation of cPLA(2) is responsible for the formation of cholesteryl ester induced by the uptake of oxLDL in macrophages, and that de novo-synthesized ceramide is implicated, at least in part, in this process.
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Affiliation(s)
- Kazuyuki Kitatani
- Department of Pathological Biochemistry, Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto 607-8414, Japan
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Furuta S, Ortiz F, Zhu Sun X, Wu HH, Mason A, Momand J. Copper uptake is required for pyrrolidine dithiocarbamate-mediated oxidation and protein level increase of p53 in cells. Biochem J 2002; 365:639-48. [PMID: 11964141 PMCID: PMC1222712 DOI: 10.1042/bj20011251] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2001] [Revised: 04/05/2002] [Accepted: 04/19/2002] [Indexed: 01/01/2023]
Abstract
The p53 tumour-suppressor protein is a transcription factor that activates the expression of genes involved in cell cycle arrest, apoptosis and DNA repair. The p53 protein is vulnerable to oxidation at cysteine thiol groups. The metal-chelating dithiocarbamates, pyrrolidine dithiocarbamate (PDTC), diethyldithiocarbamate, ethylene(bis)dithiocarbamate and H(2)O(2) were tested for their oxidative effects on p53 in cultured human breast cancer cells. Only PDTC oxidized p53, although all oxidants tested increased the p53 level. Inductively coupled plasma MS analysis indicated that the addition of 60 microM PDTC increased the cellular copper concentration by 4-fold, which was the highest level of copper accumulated amongst all the oxidants tested. Bathocuproinedisulphonic acid, a membrane-impermeable Cu(I) chelator inhibited the PDTC-mediated copper accumulation. Bathocuproinedisulphonic acid as well as the hydroxyl radical scavenger d-mannitol inhibited the PDTC-dependent increase in p53 protein and oxidation. Our results show that a low level of copper accumulation in the range of 25-40 microg/g of cellular protein increases the steady-state levels of p53. At copper accumulation levels higher than 60 microg/g of cellular protein, p53 is oxidized. These results suggest that p53 is vulnerable to free radical-mediated oxidation at cysteine residues.
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Affiliation(s)
- Saori Furuta
- Department of Chemistry and Biochemistry, California State University at Los Angeles, 5151 State University Drive, Los Angeles, CA 90032, U.S.A
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Affiliation(s)
- Hervé Benoist
- Inserm U466, Institut Louis Bugnard, CHU Rangueil, 31403 Toulouse, France
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Mazière C, Marcheux V, Louandre C, Mazière JC. Oxidized low density lipoprotein induces the cyclin-dependent kinase inhibitor p21(waf1) and the tumor suppressor Rb. Biochem Biophys Res Commun 2002; 293:1327-32. [PMID: 12054658 DOI: 10.1016/s0006-291x(02)00389-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Oxidized low density lipoprotein (OxLDL) is known to be cytotoxic towards different cell types of the arterial wall, leading to progression of an atherosclerotic plaque. We previously reported that OxLDL activates the tumor suppressor p53 in human fibroblasts [Biochem. Biophys. Res. Commun. 276 (2000) 718]. In the present work, we demonstrate that OxLDL increased intracellular levels of the kinase inhibitor p21(waf1) (p21) and of the tumor suppressor Rb. Concomitantly, level of the hypophosphorylated active form of Rb (HypoP-Rb) was also enhanced. Cycloheximide prevented the OxLDL-induced increase in p21, Rb, and HypoP-Rb, whereas okadaic acid had no effect. This increase was also prevented by the antioxidant vitamin E. In addition, the lipid extract of OxLDL, which includes the lipid peroxidation products, reproduced the action of the OxLDL particle itself. OxLDL and its lipid extract induced an oxidative stress, as assessed by the intracellular levels of reactive oxygen species and lipid peroxidation products. Finally, OxLDL induced a dose-dependent inhibition of DNA synthesis as assessed by thymidine incorporation. These results demonstrate that OxLDL or its lipid peroxidation products, by generation of an oxidative stress, enhances the expression of p21 and Rb genes, leading to an accumulation of the Hypo-P active form of the tumor suppressor Rb. This phenomenon is in accordance with the fact that p21 is a mediator of p53-dependent cell-cycle arrest in G1 and is most probably involved in the cytotoxicity of OxLDL.
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Affiliation(s)
- Cécile Mazière
- Laboratoire de Biochimie, JE 23 29, Université de Picardie Jules Verne, CHRU Amiens, Hôpital Nord, Place Victor Pauchet, 80054 Amiens Cedex 1, France.
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Mazière C, Conte MA, Mazière JC. Activation of JAK2 by the oxidative stress generated with oxidized low-density lipoprotein. Free Radic Biol Med 2001; 31:1334-40. [PMID: 11728804 DOI: 10.1016/s0891-5849(01)00649-9] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Atherosclerosis includes a series of cellular and molecular responses characteristic of an inflammatory disease. We provide evidence that cupric-ion-oxidized LDL (CuLDL) or endothelial cell-oxidized LDL (ELDL) induced the activation by Tyr-phosphorylation of JAK2, one of the Janus kinase involved upstream of STATs in the JAK/STAT pathway of cytokine transduction. Oxidized LDL (OxLDL) also initiated STAT1 and STAT3 Tyr-phosphorylation and translocation to the nucleus, with a more marked effect for the extensively modified CuLDL. Genistein, a nonspecific Tyr-kinase inhibitor, and AG490, a specific inhibitor of JAKs, markedly prevented the CuLDL-induced enhancement of STAT1 and STAT3 Tyr-phosphorylation and DNA-binding activity, suggesting that JAKs are the main kinases involved in STATs' activation by oxidized LDL. In addition, the lipid extract of CuLDL increased the intracellular levels of lipid peroxidation products and the Tyr-phosphorylation of JAK2, STAT1, and STAT3, whereas the antioxidant vitamin E prevented all these effects. These results demonstrate that OxLDL induces the activation by Tyr-phosphorylation of JAK2, STAT1, and STAT3 by generation of an intracellular oxidative stress by means of its lipid peroxidation products, and thus include JAK2 within the range of oxidative stress-activated kinases.
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Affiliation(s)
- C Mazière
- Laboratoire de Biochimie, Université de Picardie Jules Verne, Amiens, France.
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