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Sánchez-Hernández RM, Wägner AM. Should children with type 1 diabetes really receive statin treatment using the same criteria as for children with familial hypercholesterolaemia? Diabetologia 2024; 67:952-953. [PMID: 38407607 DOI: 10.1007/s00125-024-06115-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 01/26/2024] [Indexed: 02/27/2024]
Affiliation(s)
- Rosa M Sánchez-Hernández
- Endocrinology and Nutrition Department, Complejo Hospitalario Universitario Insular Materno-Infantil, Instituto de Investigaciones Biomédicas y Sanitarias (IUIBS), Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Ana M Wägner
- Endocrinology and Nutrition Department, Complejo Hospitalario Universitario Insular Materno-Infantil, Instituto de Investigaciones Biomédicas y Sanitarias (IUIBS), Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.
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2
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Lorey MB, Öörni K, Kovanen PT. Modified Lipoproteins Induce Arterial Wall Inflammation During Atherogenesis. Front Cardiovasc Med 2022; 9:841545. [PMID: 35310965 PMCID: PMC8927694 DOI: 10.3389/fcvm.2022.841545] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 01/26/2022] [Indexed: 12/15/2022] Open
Abstract
Circulating apolipoprotein B-containing lipoproteins, notably the low-density lipoproteins, enter the inner layer of the arterial wall, the intima, where a fraction of them is retained and modified by proteases, lipases, and oxidizing agents and enzymes. The modified lipoproteins and various modification products, such as fatty acids, ceramides, lysophospholipids, and oxidized lipids induce inflammatory reactions in the macrophages and the covering endothelial cells, initiating an increased leukocyte diapedesis. Lipolysis of the lipoproteins also induces the formation of cholesterol crystals with strong proinflammatory properties. Modified and aggregated lipoproteins, cholesterol crystals, and lipoproteins isolated from human atherosclerotic lesions, all can activate macrophages and thereby induce the secretion of proinflammatory cytokines, chemokines, and enzymes. The extent of lipoprotein retention, modification, and aggregation have been shown to depend largely on differences in the composition of the circulating lipoprotein particles. These properties can be modified by pharmacological means, and thereby provide opportunities for clinical interventions regarding the prevention and treatment of atherosclerotic vascular diseases.
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Affiliation(s)
- Martina B. Lorey
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Helsinki, Finland
- Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Katariina Öörni
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Helsinki, Finland
- Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- *Correspondence: Katariina Öörni
| | - Petri T. Kovanen
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Helsinki, Finland
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3
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Chen DY, Sawamura T, Dixon RAF, Sánchez-Quesada JL, Chen CH. Autoimmune Rheumatic Diseases: An Update on the Role of Atherogenic Electronegative LDL and Potential Therapeutic Strategies. J Clin Med 2021; 10:1992. [PMID: 34066436 PMCID: PMC8124242 DOI: 10.3390/jcm10091992] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/20/2021] [Accepted: 05/02/2021] [Indexed: 12/12/2022] Open
Abstract
Atherosclerosis has been linked with an increased risk of atherosclerotic cardiovascular disease (ASCVD). Autoimmune rheumatic diseases (AIRDs) are associated with accelerated atherosclerosis and ASCVD. However, the mechanisms underlying the high ASCVD burden in patients with AIRDs cannot be explained only by conventional risk factors despite disease-specific factors and chronic inflammation. Nevertheless, the normal levels of plasma low-density lipoprotein (LDL) cholesterol observed in most patients with AIRDs do not exclude the possibility of increased LDL atherogenicity. By using anion-exchange chromatography, human LDL can be divided into five increasingly electronegative subfractions, L1 to L5, or into electropositive and electronegative counterparts, LDL (+) and LDL (-). Electronegative L5 and LDL (-) have similar chemical compositions and can induce adverse inflammatory reactions in vascular cells. Notably, the percentage of L5 or LDL (-) in total LDL is increased in normolipidemic patients with AIRDs. Electronegative L5 and LDL (-) are not recognized by the normal LDL receptor but instead signal through the lectin-like oxidized LDL receptor 1 (LOX-1) to activate inflammasomes involving interleukin 1β (IL-1β). Here, we describe the detailed mechanisms of AIRD-related ASCVD mediated by L5 or LDL (-) and discuss the potential targeting of LOX-1 or IL-1β signaling as new therapeutic modalities for these diseases.
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Affiliation(s)
- Der-Yuan Chen
- Translational Medicine Center, China Medical University Hospital, Taichung 404, Taiwan;
- Rheumatology and Immunology Center, China Medical University Hospital, Taichung 404, Taiwan
- College of Medicine, China Medical University, Taichung 404, Taiwan
| | - Tatsuya Sawamura
- Department of Molecular Pathophysiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan;
- Department of Life Innovation, Institute for Biomedical Sciences, Shinshu University, Matsumoto 390-8621, Japan
| | - Richard A. F. Dixon
- Molecular Cardiology Research Laboratories, Texas Heart Institute, Houston, TX 77030, USA;
| | - José Luis Sánchez-Quesada
- Cardiovascular Biochemistry Group, Biomedical Research Institute IIB Sant Pau, 08041 Barcelona, Spain;
- CIBER of Diabetes and Metabolic Diseases (CIBERDEM), 08041 Barcelona, Spain
| | - Chu-Huang Chen
- Department of Life Innovation, Institute for Biomedical Sciences, Shinshu University, Matsumoto 390-8621, Japan
- Vascular and Medicinal Research, Texas Heart Institute, Houston, TX 77030, USA
- New York Heart Research Foundation, Mineola, NY 11501, USA
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4
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Jayaraman S, Chavez OR, Pérez A, Miñambres I, Sánchez-Quesada JL, Gursky O. Binding to heparin triggers deleterious structural and biochemical changes in human low-density lipoprotein, which are amplified in hyperglycemia. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158712. [PMID: 32289504 DOI: 10.1016/j.bbalip.2020.158712] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/31/2020] [Accepted: 04/08/2020] [Indexed: 12/15/2022]
Abstract
Low-density lipoprotein (LDL) binding to arterial proteoglycans initiates LDL retention and modification in the arterial wall, triggering atherosclerosis. The details of this binding, its effectors, and its ramifications are incompletely understood. We combined heparin affinity chromatography with biochemical, spectroscopic and electron microscopic techniques to show that brief binding to heparin initiates irreversible pro-atherogenic remodeling of human LDL. This involved decreased structural stability of LDL and increased susceptibility to hydrolysis, oxidation and fusion. Furthermore, phospholipid hydrolysis, mild oxidation and/or glycation of LDL in vitro increase the proteolytic susceptibility of apoB and its heparin binding affinity, perhaps by unmasking additional heparin-binding sites. For LDL from hyperglycemic type-2 diabetic patients, heparin binding was particularly destabilizing and caused apoB fragmentation and LDL fusion. However, for similar patients whose glycemic control was restored upon therapy, LDL-heparin binding affinity was rectified and LDL structural stability was partially restored. These results complement previous studies of LDL binding to arterial proteoglycans and suggest that such interactions may produce a particularly pro-atherogenic subclass of electronegative LDL. In summary, binding to heparin alters apoB conformation, perhaps by partially peeling it off the lipid, and triggers pro-atherogenic LDL modifications including hydrolysis, oxidation, and destabilization. Furthermore, phospholipid lipolysis, mild oxidation and glycation of LDL in vitro strengthen its binding to heparin, which helps explain stronger binding observed in hyperglycemic LDL. Combined effects of hyperglycemia and heparin binding are especially deleterious but are largely rectified upon diabetes therapy. These findings help establish a mechanistic link between diabetes and atherosclerosis.
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Affiliation(s)
- Shobini Jayaraman
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA 02118, USA.
| | - Olivia R Chavez
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA 02118, USA
| | - Antonio Pérez
- Endocrinology Department of the Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; CIBER of Diabetes and Metabolic Diseases (CIBERDEM), Spain
| | - Inka Miñambres
- Endocrinology Department of the Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Jose Luis Sánchez-Quesada
- CIBER of Diabetes and Metabolic Diseases (CIBERDEM), Spain; Cardiovascular Biochemistry Group, Research Institute of the Hospital de Sant Pau, CIBERDEM, Barcelona, Spain
| | - Olga Gursky
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA 02118, USA; Amyloidosis Treatment and Research Center, Boston University School of Medicine, Boston MA, USA
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5
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Rivas-Urbina A, Rull A, Ordóñez-Llanos J, Sánchez-Quesada JL. Electronegative LDL: An Active Player in Atherogenesis or a By- Product of Atherosclerosis? Curr Med Chem 2019; 26:1665-1679. [PMID: 29600751 DOI: 10.2174/0929867325666180330093953] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 11/12/2017] [Accepted: 12/11/2017] [Indexed: 12/16/2022]
Abstract
Low-density lipoproteins (LDLs) are the major plasma carriers of cholesterol. However, LDL particles must undergo various molecular modifications to promote the development of atherosclerotic lesions. Modified LDL can be generated by different mechanisms, but as a common trait, show an increased electronegative charge of the LDL particle. A subfraction of LDL with increased electronegative charge (LDL(-)), which can be isolated from blood, exhibits several pro-atherogenic characteristics. LDL(-) is heterogeneous, due to its multiple origins but is strongly related to the development of atherosclerosis. Nevertheless, the implication of LDL(-) in a broad array of pathologic conditions is complex and in some cases anti-atherogenic LDL(-) properties have been reported. In fact, several molecular modifications generating LDL(-) have been widely studied, but it remains unknown as to whether these different mechanisms are specific or common to different pathological disorders. In this review, we attempt to address these issues examining the most recent findings on the biology of LDL(-) and discussing the relationship between this LDL subfraction and the development of different diseases with increased cardiovascular risk. Finally, the review highlights the importance of minor apolipoproteins associated with LDL(-) which would play a crucial role in the different properties displayed by these modified LDL particles.
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Affiliation(s)
- Andrea Rivas-Urbina
- Cardiovascular Biochemistry Group, Research Institute of the Hospital de Sant Pau (IIB Sant Pau), Barcelona, Spain.,Biochemistry and Molecular Biology Department, Universitat Autònoma de Barcelona, Cerdanyola, Spain
| | - Anna Rull
- Cardiovascular Biochemistry Group, Research Institute of the Hospital de Sant Pau (IIB Sant Pau), Barcelona, Spain.,Hospital Universitari Joan XXIII, IISPV, Universitat Rovira i Virgili, Tarragona, Spain
| | - Jordi Ordóñez-Llanos
- Cardiovascular Biochemistry Group, Research Institute of the Hospital de Sant Pau (IIB Sant Pau), Barcelona, Spain.,Biochemistry and Molecular Biology Department, Universitat Autònoma de Barcelona, Cerdanyola, Spain
| | - José Luis Sánchez-Quesada
- Cardiovascular Biochemistry Group, Research Institute of the Hospital de Sant Pau (IIB Sant Pau), Barcelona, Spain.,CIBERDEM. Institute of Health Carlos III, Madrid 28029, Spain
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6
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Estruch M, Miñambres I, Sanchez-Quesada JL, Soler M, Pérez A, Ordoñez-Llanos J, Benitez S. Increased inflammatory effect of electronegative LDL and decreased protection by HDL in type 2 diabetic patients. Atherosclerosis 2017; 265:292-298. [PMID: 28734591 DOI: 10.1016/j.atherosclerosis.2017.07.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 07/04/2017] [Accepted: 07/12/2017] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND AIMS Type 2 diabetic patients have an increased proportion of electronegative low-density lipoprotein (LDL(-)), an inflammatory LDL subfraction present in blood, and dysfunctional high-density lipoprotein (HDL). We aimed at examining the inflammatory effect of LDL(-) on monocytes and the counteracting effect of HDL in the context of type 2 diabetes. METHODS This was a cross-sectional study in which the population comprised 3 groups (n = 12 in each group): type 2 diabetic patients with good glycaemic control (GC-T2DM patients), type 2 diabetic patients with poor glycaemic control (PC-T2DM), and a control group. Total LDL, HDL, and monocytes were isolated from plasma of these subjects. LDL(-) was isolated from total LDL by anion-exchange chromatography. LDL(-) from the three groups of subjects was added to monocytes in the presence or absence of HDL, and cytokines released by monocytes were quantified by ELISA. RESULTS LDL(-) proportion and plasma inflammatory markers were increased in PC-T2DM patients. LDL(-) from PC-T2DM patients induced the highest IL1β, IL6, and IL10 release in monocytes compared to LDL(-) from GC-T2DM and healthy subjects, and presented the highest content of non-esterified fatty acids (NEFA). In turn, HDL from PC-T2DM patients showed the lowest ability to inhibit LDL(-)-induced cytokine release in parallel to an impaired ability to decrease NEFA content in LDL(-). CONCLUSIONS Our findings show an imbalance in the pro- and anti-inflammatory effects of lipoproteins from T2DM patients, particularly in PC-T2DM.
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Affiliation(s)
- Montserrat Estruch
- Cardiovascular Biochemistry, Biomedical Research Institute Sant Pau (IIB-Sant Pau), C/Sant Antoni M. Claret 167, 08025 Barcelona, Spain
| | - Inka Miñambres
- Endocrinology and Nutrition Department, Hospital de la Santa Creu i Sant Pau Barcelona, C/Sant Quintí 89, 08026 Barcelona, Spain
| | - Jose Luis Sanchez-Quesada
- Cardiovascular Biochemistry, Biomedical Research Institute Sant Pau (IIB-Sant Pau), C/Sant Antoni M. Claret 167, 08025 Barcelona, Spain; Molecular Biology and Biochemistry Department, Universitat Autònoma de Barcelona (UAB) Faculty of Medicine, Building M. Cerdanyola del Vallès, Spain
| | - Marta Soler
- Flow Cytometry Platform, Biomedical Research Institute Sant Pau (IIB-Sant Pau), C/Sant Antoni M. Claret 167, 08025 Barcelona, Spain
| | - Antonio Pérez
- Endocrinology and Nutrition Department, Hospital de la Santa Creu i Sant Pau Barcelona, C/Sant Quintí 89, 08026 Barcelona, Spain
| | - Jordi Ordoñez-Llanos
- Molecular Biology and Biochemistry Department, Universitat Autònoma de Barcelona (UAB) Faculty of Medicine, Building M. Cerdanyola del Vallès, Spain; Biochemistry Department, Hospital de la Santa Creu i Sant Pau Barcelona, C/Sant Quintí 89, 08026 Barcelona, Spain
| | - Sonia Benitez
- Cardiovascular Biochemistry, Biomedical Research Institute Sant Pau (IIB-Sant Pau), C/Sant Antoni M. Claret 167, 08025 Barcelona, Spain; Molecular Biology and Biochemistry Department, Universitat Autònoma de Barcelona (UAB) Faculty of Medicine, Building M. Cerdanyola del Vallès, Spain.
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7
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Sonmez E, Cacciatore I, Bakan F, Turkez H, Mohtar YI, Togar B, Stefano AD. Toxicity assessment of hydroxyapatite nanoparticles in rat liver cell model in vitro. Hum Exp Toxicol 2016; 35:1073-83. [DOI: 10.1177/0960327115619770] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Hydroxyapatite nanoparticles (HAP NPs) are widely used for preparations of biomedical and biotechnological fields such as drug delivery, gene therapy, and molecular imaging. However, the current toxicological knowledge about HAP NPs is relatively limited. The present study was designed to investigate the toxicity potentials of various concentrations (0–1000 µg cm−2) of HAP NPs in cultured primary rat hepatocytes. Cell viability was detected by 3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay and lactate dehydrogenase (LDH) release, while total antioxidant capacity (TAC) and total oxidative stress (TOS) levels were determined to evaluate the oxidative injury. The DNA damage was also analyzed via scoring liver micronuclei rates and determining 8-oxo-2-deoxyguanosine (8-OH-dG) levels. The results of MTT and LDH assays showed that the higher concentrations of dispersed HAP NPs (300, 500, and 1000 µg cm−2) decreased cell viability. Also, HAP NPs increased TOS (500 and 1000 µg cm−2) levels and decreased TAC (300, 500, and 1000 µg cm−2) levels in cultured hepatocytes. On the basis of increasing doses, the NPs as depending on dose caused significant increases of the number of micronucleated hepatocytes and 8-OH-dG levels as compared to control culture. Furthermore, the highest concentration of HAP NPs (1000 µg cm−2) exhibited cytotoxic activity. Based on these results, HAP NPs have a dose-dependent toxic effect in rat hepatocytes. Further extensive research in this field is promising and reasonable.
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Affiliation(s)
- E Sonmez
- Department of Physics, Faculty of K. K. Education, Atatürk University, Erzurum, Turkey
- Advanced Materials Research Laboratory, Department of Nanoscience and Nanoengineering, Graduate School of Natural and Applied Sciences, Atatürk University, Erzurum, Turkey
| | - I Cacciatore
- Department of Pharmacology, G. D’Annunzio University, Chieti, Italy
| | - F Bakan
- SUNUM, Sabanci University, Tuzla, Istanbul, Turkey
| | - H Turkez
- Department of Pharmacology, G. D’Annunzio University, Chieti, Italy
- Department of Molecular Biology and Genetics, Faculty of Science, Erzurum Technical University, Erzurum, Turkey
| | - YI Mohtar
- Department of Environmental Studies, Institute of Graduate Studies and Research, Alexandria University, Alexandria, Egypt
| | - B Togar
- Department of Biology, Faculty of Science, Atatürk University, Erzurum, Turkey
| | - AD Stefano
- Department of Pharmacology, G. D’Annunzio University, Chieti, Italy
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8
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Cavalcante MF, Kazuma SM, Bender EA, Adorne MD, Ullian M, Veras MM, Saldiva PHN, Maranhão AQ, Guterres SS, Pohlmann AR, Abdalla DSP. A nanoformulation containing a scFv reactive to electronegative LDL inhibits atherosclerosis in LDL receptor knockout mice. Eur J Pharm Biopharm 2016; 107:120-9. [PMID: 27378286 DOI: 10.1016/j.ejpb.2016.07.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 06/24/2016] [Accepted: 07/01/2016] [Indexed: 01/21/2023]
Abstract
Atherosclerosis is a chronic inflammatory disease responsible for the majority of cases of myocardial infarction and ischemic stroke. The electronegative low-density lipoprotein, a modified subfraction of native LDL, is pro-inflammatory and plays an important role in atherogenesis. To investigate the effects of a nanoformulation (scFv anti-LDL(-)-MCMN-Zn) containing a scFv reactive to LDL(-) on the inhibition of atherosclerosis, its toxicity was evaluated in vitro and in vivo and further it was also administered weekly to LDL receptor knockout mice. The scFv anti-LDL(-)-MCMN-Zn nanoformulation did not induce cell death in RAW 264.7 macrophages and HUVECs. The 5mg/kg dose of scFv anti-LDL(-)-MCMN-Zn did not cause any typical signs of toxicity and it was chosen for the evaluation of its atheroprotective effect in Ldlr(-/-) mice. This nanoformulation significantly decreased the atherosclerotic lesion area at the aortic sinus, compared with that in untreated mice. In addition, the Il1b mRNA expression and CD14 protein expression were downregulated in the atherosclerotic lesions at the aortic arch of Ldlr(-/-) mice treated with scFv anti-LDL(-)-MCMN-Zn. Thus, the scFv anti-LDL(-)-MCMN-Zn nanoformulation inhibited the progression of atherosclerotic lesions, indicating its potential use in a future therapeutic strategy for atherosclerosis.
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Affiliation(s)
- Marcela Frota Cavalcante
- Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Soraya Megumi Kazuma
- Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Eduardo André Bender
- Department of Organic Chemistry, Chemistry Institute, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Márcia Duarte Adorne
- Department of Organic Chemistry, Chemistry Institute, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Mayara Ullian
- Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Mariana Matera Veras
- LIM5, Department of Pathology, Medicine School, University of Sao Paulo, Sao Paulo, SP, Brazil
| | | | - Andrea Queiroz Maranhão
- Molecular Immunology Laboratory, Department of Cell Biology, University of Brasilia, Brasilia, Distrito Federal, Brazil
| | - Silvia Stanisçuaski Guterres
- Department of Production and Control of Medicines, Faculty of Pharmacy, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Adriana Raffin Pohlmann
- Department of Organic Chemistry, Chemistry Institute, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Dulcineia Saes Parra Abdalla
- Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil.
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9
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Estruch M, Sanchez-Quesada JL, Ordoñez-Llanos J, Benitez S. Inflammatory intracellular pathways activated by electronegative LDL in monocytes. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:963-969. [PMID: 27235719 DOI: 10.1016/j.bbalip.2016.05.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 05/10/2016] [Accepted: 05/23/2016] [Indexed: 12/12/2022]
Abstract
AIMS Electronegative LDL (LDL(-)) is a plasma LDL subfraction that induces cytokine release in monocytes through toll-like receptor 4 (TLR4) activation. However, the intracellular pathways induced by LDL(-) downstream TLR4 activation are unknown. We aimed to identify the pathways activated by LDL(-) leading to cytokine release in monocytes. METHODS AND RESULTS We determined LDL(-)-induced activation of several intracellular kinases in protein extracts from monocytes using a multikinase ELISA array. LDL(-) induced higher p38 mitogen-activated protein kinase (MAPK) phosphorylation than native LDL. This was corroborated by a specific cell-based assay and it was dependent on TLR4 and phosphoinositide 3-kinase (PI3k)/Akt pathway. P38 MAPK activation was involved in cytokine release promoted by LDL(-). A specific ELISA showed that LDL(-) activated cAMP response-element binding (CREB) in a p38 MAPK dependent manner. P38 MAPK was also involved in the nuclear factor kappa-B (NF-kB) and activating protein-1 (AP-1) activation by LDL(-). We found that NF-kB, AP-1 and CREB inhibitors decreased LDL(-)-induced cytokine release, mainly on MCP1, IL6 and IL10 release, respectively. CONCLUSIONS LDL(-) promotes p38 MAPK phosphorylation through TLR4 and PI3k/Akt pathways. Phosphorylation of p38 MAPK is involved in NF-kB, AP-1 and CREB activation, leading to LDL(-)-induced cytokine release in monocytes.
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Affiliation(s)
- Montserrat Estruch
- Biomedical Research Institute Sant Pau (IIB-Sant Pau), Barcelona, Spain, C/Sant Antoni M. Claret 167, 08025 Barcelona, Spain.
| | - Jose Luis Sanchez-Quesada
- Biomedical Research Institute Sant Pau (IIB-Sant Pau), Barcelona, Spain, C/Sant Antoni M. Claret 167, 08025 Barcelona, Spain; Molecular Biology and Biochemistry Department, Universitat Autònoma de Barcelona (UAB) Faculty of Medicine, Building M. Cerdanyola del Vallès, Spain.
| | - Jordi Ordoñez-Llanos
- Molecular Biology and Biochemistry Department, Universitat Autònoma de Barcelona (UAB) Faculty of Medicine, Building M. Cerdanyola del Vallès, Spain; Biochemistry Department, Hospital de la Santa Creu i Sant Pau Barcelona, C/Sant Quintí 89, 08026 Barcelona, Spain.
| | - Sonia Benitez
- Biomedical Research Institute Sant Pau (IIB-Sant Pau), Barcelona, Spain, C/Sant Antoni M. Claret 167, 08025 Barcelona, Spain; Molecular Biology and Biochemistry Department, Universitat Autònoma de Barcelona (UAB) Faculty of Medicine, Building M. Cerdanyola del Vallès, Spain.
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10
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Plasma PAF-AH (PLA2G7): Biochemical Properties, Association with LDLs and HDLs, and Regulation of Expression. Enzymes 2015; 38:71-93. [PMID: 26612648 DOI: 10.1016/bs.enz.2015.09.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
This chapter is focused on the plasma form of PAF-acetylhydrolase (PAF-AH), a lipoprotein-bound, calcium-independent phospholipase A2 activity also referred to as lipoprotein-associated phospholipase A2 and PLA2G7. PAF-AH catalyzes the removal of the acyl group at the sn-2 position of PAF and truncated phospholipids generated in settings of inflammation and oxidant stress. Here, I discuss current knowledge related to the structural features of this enzyme, including the molecular basis for association with lipoproteins and susceptibility to oxidative inactivation. The circulating form of PAF-AH is constitutively active and its expression is upregulated by mediators of inflammation at the transcriptional level. Several new mechanisms of regulation have been identified in recent years, including effects mediated by PPARs, VEGFR, and the state of cellular differentiation. Moreover, I discuss recent studies describing significant variations in the structure and regulation of PAF-AH from diverse species, which is likely to have important implications for the function of this enzyme in vivo.
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11
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Revuelta-López E, Cal R, Julve J, Rull A, Martínez-Bujidos M, Perez-Cuellar M, Ordoñez-Llanos J, Badimon L, Sanchez-Quesada JL, Llorente-Cortés V. Hypoxia worsens the impact of intracellular triglyceride accumulation promoted by electronegative low-density lipoprotein in cardiomyocytes by impairing perilipin 5 upregulation. Int J Biochem Cell Biol 2015; 65:257-67. [DOI: 10.1016/j.biocel.2015.06.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 06/03/2015] [Accepted: 06/12/2015] [Indexed: 10/23/2022]
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12
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Critical Role of Prohibitin in Endothelial Cell Apoptosis Caused by Glycated Low-density Lipoproteins and Protective Effects of Grape Seed Procyanidin B2. J Cardiovasc Pharmacol 2015; 65:13-21. [DOI: 10.1097/fjc.0000000000000157] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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13
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14
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Silva ITD, Mello APDQ, Sanches LB, Abdalla DSP, Damasceno NRT. Is plasma alpha-tocopherol associated with electronegative LDL in obese adolescents? J Nutr Sci Vitaminol (Tokyo) 2014; 59:100-7. [PMID: 23727639 DOI: 10.3177/jnsv.59.100] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Obesity has increased in children and adolescents. What is reflected in the early occurrence of cardiometabolic alterations, like hypertension and type 2 diabetes, where the oxLDL formation is stimulated. Various studies have shown that plasma α-tocopherol (α-TP) can protect LDL against oxidation. Nevertheless, the action of plasma α-TP in cardiovascular diseases remains controversial. We conducted a cross-sectional study to evaluate plasma α-TP and its impact on the concentration of LDL(-). Adolescents (n=150) of both sexes were classified into three groups: healthy weight (HW; 50%), overweight (OV; 22%), and obese (OB; 28%). Lipid profile, LDL(-), anti-oxLDL and anti-LDL(-) antibodies, CRP (ELISA) and plasma α-TP (HPLC) were analyzed. Demographic, anthropometric, and food intake data were evaluated. Crude and energy-adjusted intake of vitamin E in the OB group were higher than in the HW group (p<0.001). Crude and energy-adjusted vitamin E intakes were not correlated with plasma α-TP (r=-0.07; p=0.412 and r=-0.064; p=0.467, respectively). Subjects in the OB group had higher TC and LDL-C and lower HDL-C than in the HW and OV groups. C-reactive protein and anti-oxLDL antibodies changed as a function of BMI. The impact of obesity was reinforced by high values for LDL(-) and low content of plasma α-TP in comparison with the HW (p<0.001) and OV groups (p=0.03). This negative profile was maintained for the ratio between α-TP and TC or LDL-C. Plasma α-TP, α-TP/TC and α-TP/LDL-C were negatively associated with LDL(-) and other cardiometabolic risk factors (BMI, WC, AC and anti-oxLDL). Our results demonstrate that obesity in adolescents is associated with high levels of LDL(-) and low plasma α-TP content.
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Affiliation(s)
- Isis Tande da Silva
- Department of Nutrition, School of Public Health, University of São Paulo, SP, Brazil.
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Lipoproteínas modificadas como marcadores de riesgo cardiovascular en la diabetes mellitus. ACTA ACUST UNITED AC 2013; 60:518-28. [DOI: 10.1016/j.endonu.2012.12.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 12/17/2012] [Accepted: 12/19/2012] [Indexed: 11/17/2022]
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16
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Electronegative LDL: a circulating modified LDL with a role in inflammation. Mediators Inflamm 2013; 2013:181324. [PMID: 24062611 PMCID: PMC3766570 DOI: 10.1155/2013/181324] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 07/19/2013] [Indexed: 12/13/2022] Open
Abstract
Electronegative low density lipoprotein (LDL(−)) is a minor modified fraction of LDL found in blood. It comprises a heterogeneous population of LDL particles modified by various mechanisms sharing as a common feature increased electronegativity. Modification by oxidation is one of these mechanisms. LDL(−) has inflammatory properties similar to those of oxidized LDL (oxLDL), such as inflammatory cytokine release in leukocytes and endothelial cells. However, in contrast with oxLDL, LDL(−) also has some anti-inflammatory effects on cultured cells. The inflammatory and anti-inflammatory properties ascribed to LDL(−) suggest that it could have a dual biological effect.
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Bernal-Lopez MR, Llorente-Cortes V, Calleja F, Lopez-Carmona D, Mayas MD, Gomez-Huelgas R, Badimon L, Tinahones FJ. Effect of different degrees of impaired glucose metabolism on the expression of inflammatory markers in monocytes of patients with atherosclerosis. Acta Diabetol 2013; 50:553-62. [PMID: 21997325 DOI: 10.1007/s00592-011-0337-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 09/26/2011] [Indexed: 12/11/2022]
Abstract
Inflammatory markers are elevated in type 2 diabetic patients (DP) and may predict the development of type 2 diabetes. Our aims were to analyze differences in the expression of inflammatory and immunological molecules between DP and healthy subjects and to investigate whether glycemic control might prevent the overexpression of inflammatory markers in DP. Twenty-two DP with advanced atherosclerosis and eight healthy blood donors were included. DP were classified as well (HbA1c ≤ 6.5) or poorly controlled (HbA1c > 6.5). In "in vitro" studies, monocytes were exposed to low (5.5 mM) or high glucose (26 mM) concentrations in the absence or presence of insulin. Expression profiling of 14 inflammatory genes was analyzed using TLDA analysis. "In vivo" results show that monocytes from DP had increased levels of monocyte chemoattractant protein (MCP-1) and interleukin 6 (IL6) and lower levels of Toll-like receptor 2 (TLR2) mRNA than healthy subjects. Well-controlled DP had lower levels of IL-6 than poorly controlled DP, suggesting that glycemic control may prevent IL6 mRNA alterations associated with diabetes. "In vitro" results demonstrate that glucose directly and significantly induced MCP-1 and IL6 and reduced TLR2 mRNA expression. Insulin at high dose (100 IU/ml) dramatically enhanced the upregulatory effects of glucose on MCP-1 and IL-6 and reduced per se TLR2 mRNA expression. MCP-1, IL-6 and TLR2 are key inflammatory players altered in monocytes from type 2 DP. Both hyperinsulinemia and hyperglycemia contribute to alter the expression of these genes. The glycemic control only significantly prevented IL6 overexpression in this group of patients.
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Affiliation(s)
- M R Bernal-Lopez
- Biomedical Research Laboratory, Endocrinology Department, Hospital Virgen de la Victoria, Malaga, Spain
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18
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Kitabayashi C, Naruko T, Sugioka K, Yunoki K, Nakagawa M, Inaba M, Ohsawa M, Konishi Y, Imanishi M, Inoue T, Itabe H, Yoshiyama M, Haze K, Becker AE, Ueda M. Positive association between plasma levels of oxidized low-density lipoprotein and myeloperoxidase after hemodialysis in patients with diabetic end-stage renal disease. Hemodial Int 2013; 17:557-67. [DOI: 10.1111/hdi.12049] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Chizuko Kitabayashi
- Department of Pathology; Osaka City University Graduate School of Medicine; Tokyo Japan
| | - Takahiko Naruko
- Department of Cardiology; Osaka City General Hospital; Tokyo Japan
| | - Kenichi Sugioka
- Department of Internal Medicine and Cardiology; Osaka City University Graduate School of Medicine; Tokyo Japan
| | - Kei Yunoki
- Department of Cardiology; Osaka City General Hospital; Tokyo Japan
| | - Masashi Nakagawa
- Department of Internal Medicine and Cardiology; Osaka City University Graduate School of Medicine; Tokyo Japan
| | - Mayumi Inaba
- Department of Pathology; Osaka City University Graduate School of Medicine; Tokyo Japan
| | - Masahiko Ohsawa
- Department of Surgical Pathology; Osaka City University Graduate School of Medicine; Tokyo Japan
| | - Yoshio Konishi
- Division of Nephrology and Hypertension; Osaka City General Hospital; Tokyo Japan
| | - Masahito Imanishi
- Division of Nephrology and Hypertension; Osaka City General Hospital; Tokyo Japan
| | - Takeshi Inoue
- Department of Pathology; Osaka City General Hospital; Tokyo Japan
| | - Hiroyuki Itabe
- Department of Biological Chemistry; School of Pharmaceutical Sciences; Showa University; Tokyo Japan
| | - Minoru Yoshiyama
- Department of Internal Medicine and Cardiology; Osaka City University Graduate School of Medicine; Tokyo Japan
| | - Kazuo Haze
- Department of Cardiology; Osaka City General Hospital; Tokyo Japan
| | - Anton E. Becker
- Academic Medical Center; University of Amsterdam; Amsterdam The Netherlands
| | - Makiko Ueda
- Department of Pathology; Osaka City University Graduate School of Medicine; Tokyo Japan
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Wang GJ, Chang CT, Yang CY, Chen CH. Negatively charged L5 as a naturally occurring atherogenic low-density lipoprotein. Biomedicine (Taipei) 2012. [DOI: 10.1016/j.biomed.2012.05.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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Panee J. Monocyte Chemoattractant Protein 1 (MCP-1) in obesity and diabetes. Cytokine 2012; 60:1-12. [PMID: 22766373 DOI: 10.1016/j.cyto.2012.06.018] [Citation(s) in RCA: 283] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 05/30/2012] [Accepted: 06/04/2012] [Indexed: 12/23/2022]
Abstract
Monocyte Chemoattractant Protein-1 (MCP-1) is the first discovered and most extensively studied CC chemokine, and the amount of studies on its role in the etiologies of obesity- and diabetes-related diseases have increased exponentially during the past two decades. This review attempted to provide a panoramic perspective of the history, regulatory mechanisms, functions, and therapeutic strategies of this chemokine. The highlights of this review include the roles of MCP-1 in the development of obesity, diabetes, cardiovascular diseases, insulitis, diabetic nephropathy, and diabetic retinopathy. Therapies that specifically or non-specifically inhibit MCP-1 overproduction have been summarized.
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Affiliation(s)
- Jun Panee
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo Street BSB 222, Honolulu, HI 96813, USA.
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Sánchez-Quesada JL, Estruch M, Benítez S, Ordóñez-Llanos J. Electronegative LDL: a useful biomarker of cardiovascular risk? ACTA ACUST UNITED AC 2012. [DOI: 10.2217/clp.12.26] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Lobo JC, Mafra D, Farage NE, Faulin TDES, Abdalla DSP, de Nóbrega ACL, Torres JPM. Increased electronegative LDL and decreased antibodies against electronegative LDL levels correlate with inflammatory markers and adhesion molecules in hemodialysed patients. Clin Chim Acta 2011; 412:1788-92. [DOI: 10.1016/j.cca.2011.05.034] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 05/31/2011] [Accepted: 05/31/2011] [Indexed: 10/18/2022]
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23
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Dullaart RPF, Constantinides A, Perton FG, van Leeuwen JJJ, van Pelt JL, de Vries R, van Tol A. Plasma cholesteryl ester transfer, but not cholesterol esterification, is related to lipoprotein-associated phospholipase A2: possible contribution to an atherogenic lipoprotein profile. J Clin Endocrinol Metab 2011; 96:1077-84. [PMID: 21252249 DOI: 10.1210/jc.2010-2139] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
CONTEXT Plasma lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) predicts incident cardiovascular disease and is associated preferentially with negatively charged apolipoprotein B-containing lipoproteins. The plasma cholesteryl ester transfer (CET) process, which contributes to low high-density lipoprotein cholesterol and small, dense low-density lipoproteins, is affected by the composition and concentration of apolipoprotein B-containing cholesteryl ester acceptor lipoproteins. OBJECTIVE We tested relationships of CET with Lp-PLA(2) in subjects with and without metabolic syndrome (MetS). DESIGN AND SETTING In 68 subjects with MetS and 74 subjects without MetS, plasma Lp-PLA(2) mass, cholesterol esterification (EST), lecithin:cholesterol acyltransferase (LCAT) activity level, CET, CET protein (CETP) mass, and lipoproteins were measured. RESULTS EST, LCAT activity, CET (P < 0.001 for all), and CETP (P = 0.030) were increased, and Lp-PLA(2) was decreased (P = 0.043) in MetS. CET was correlated positively with Lp-PLA(2) in subjects with and without MetS (P < 0.05 for both). EST and LCAT activity were unrelated to Lp-PLA(2), despite a positive correlation between EST and CET (P < 0.001). After controlling for age, sex, and diabetes status, CET was determined by Lp-PLA(2) in the whole group (β = 0.245; P < 0.001), and in subjects with (β = 0.304; P = 0.001) and without MetS (β = 0.244; P = 0.006) separately, independently of triglycerides and CETP. CONCLUSIONS Plasma CET is related to Lp-PLA(2) in subjects with and without MetS. The process of CET, but not EST, may be influenced by Lp-PLA(2). These findings provide a rationale to evaluate whether maneuvers that inhibit Lp-PLA(2) will reduce CET, and vice versa to document effects of CETP inhibition on Lp-PLA(2).
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Affiliation(s)
- Robin P F Dullaart
- Department of Endocrinology, University of Groningen and University Medical Center Groningen, 9700 RB Groningen, The Netherlands.
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Electronegative low-density lipoprotein: Origin and impact on health and disease. Atherosclerosis 2011; 215:257-65. [DOI: 10.1016/j.atherosclerosis.2010.12.028] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 11/25/2010] [Accepted: 12/30/2010] [Indexed: 11/17/2022]
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25
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Suckling K. Phospholipase A2s: Developing drug targets for atherosclerosis. Atherosclerosis 2010; 212:357-66. [DOI: 10.1016/j.atherosclerosis.2010.03.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Revised: 03/08/2010] [Accepted: 03/08/2010] [Indexed: 12/24/2022]
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26
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Faulin TDES, Cavalcante MF, Abdalla DSP. Role of electronegative LDL and its associated antibodies in the pathogenesis of atherosclerosis. ACTA ACUST UNITED AC 2010. [DOI: 10.2217/clp.10.52] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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27
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Cheng L, Han X, Shi Y. A regulatory role of LPCAT1 in the synthesis of inflammatory lipids, PAF and LPC, in the retina of diabetic mice. Am J Physiol Endocrinol Metab 2009; 297:E1276-82. [PMID: 19773578 PMCID: PMC2793047 DOI: 10.1152/ajpendo.00475.2009] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Platelet-activating factor (PAF) and lysophosphatidylcholine (LPC) are potent inflammatory lipids. Elevated levels of PAF and LPC are associated with the onset of diabetic retinopathy and neurodegeneration. However, the molecular mechanisms underlying such defects remain elusive. LPCAT1 is a newly reported lysophospholipid acyltransferase implicated in the anti-inflammatory response by its role in conversion of LPC to PC. Intriguingly, the LPCAT1 enzyme also catalyzes the synthesis of PAF from lyso-PAF with use of acetyl-CoA as a substrate. The present studies investigated regulatory roles of LPCAT1 in the synthesis of inflammatory lipids during the onset of diabetes. Our work shows that LPCAT1 plays an important role in the inactivation of PAF by catalyzing the synthesis of alkyl-PC, an inactivated form of PAF with use of acyl-CoA and lyso-PAF as substrates. In support of a role of LPCAT1 in anti-inflammatory responses in diabetic retinopathy, LPCAT1 is most abundantly expressed in the retina. Moreover, LPCAT1 mRNA levels and acyltransferase activity toward lyso-PAF and LPC were significantly downregulated in retina and brain tissues in response to the onset of diabetes in Ins2(Akita) and db/db mice, mouse models of type 1 and type 2 diabetes, respectively. Conversely, treatment of db/db mice with rosiglitazone, an antidiabetes compound, significantly upregulated LPCAT1 mRNA levels concurrently with increased acyltransferase activity in the retina and brain. Collectively, these findings identified a novel regulatory role of LPCAT1 in catalyzing the inactivation of inflammatory lipids in the retina of diabetic mice.
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Affiliation(s)
- Long Cheng
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
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Mafra D, Santos FR, Lobo JC, de Mattos Grosso D, Barreira AL, Velarde LGC, Abdalla DSP, Leite M. Alpha-tocopherol supplementation decreases electronegative low-density lipoprotein concentration [LDL(-)] in haemodialysis patients. Nephrol Dial Transplant 2009; 24:1587-92. [PMID: 19176686 DOI: 10.1093/ndt/gfn760] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Oxidative stress is a significant contributor to cardiovascular diseases (CVD) in haemodialysis (HD) patients, predisposing to the generation of oxidized low-density lipoprotein (oxLDL) or electronegatively charged LDL subfraction. Antioxidant therapy such as alpha-tocopherol acts as a scavenger of lipid peroxyl radicals attenuating the oxidative stress, which decreases the formation of oxLDL. The present study was designed to investigate the influence of the alpha-tocopherol supplementation on the concentration of electronegative low-density lipoprotein [LDL(-)], a minimally oxidized LDL, which we have previously described to be high in HD patients. METHODS Blood samples were collected before and after 120 days of supplementation by alpha-tocopherol (400 UI/day) in 19 stable HD patients (50 +/- 7.8 years; 9 males). The concentrations of LDL(-) in blood plasma [using an anti-LDL- human monoclonal antibody (mAb)] and the anti-LDL(-) IgG auto-antibodies were determined by ELISA. Calculation of body mass index (BMI) and measurements of waist circumference (WC), triceps skin folds (TSF) and arm muscle area (AMA) were performed. RESULTS The plasma alpha-tocopherol levels increased from 7.9 microM (0.32-18.4) to 14.2 microM (1.22-23.8) after the supplementation (P = 0.02). The mean concentration of LDL(-) was reduced from 570.9 microg/mL (225.6-1241.0) to 169.1 microg/mL (63.6-621.1) (P < 0.001). The anti-LDL(-) IgG auto-antibodies did not change significantly after the supplementation. The alpha-tocopherol supplementation also reduced the total cholesterol and LDL-C levels in these patients, from 176 +/- 42.3 mg/dL to 120 +/- 35.7 mg/dL (P < 0.05) and 115.5 +/- 21.4 mg/dL to 98.5 +/- 23.01 mg/dL (P < 0.001), respectively. CONCLUSION The oral administration of alpha-tocopherol in HD patients resulted in a significant decrease in the LDL(-), total cholesterol and LDL-C levels. This effect may favour a reduction in cardiovascular risk in these patients, but a larger study is required to confirm an effect in this clinical setting.
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Affiliation(s)
- Denise Mafra
- Department of Clinical Nutrition, Federal Fluminense University (UFF), Niterói, Brazil.
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Stafforini DM. Biology of platelet-activating factor acetylhydrolase (PAF-AH, lipoprotein associated phospholipase A2). Cardiovasc Drugs Ther 2008; 23:73-83. [PMID: 18949548 DOI: 10.1007/s10557-008-6133-8] [Citation(s) in RCA: 161] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Accepted: 08/06/2008] [Indexed: 12/26/2022]
Abstract
INTRODUCTION This article is focused on platelet-activating factor acetylhydrolase (PAF-AH), a lipoprotein bound, calcium-independent phospholipase A(2) activity also referred to as lipoprotein-associated phospholipase A(2) or PLA(2)G7. PAF-AH catalyzes the removal of the acyl group at the sn-2 position of PAF and truncated phospholipids generated in settings of inflammation and oxidant stress. DISCUSSION Here, I discuss current knowledge related to the structural features of this enzyme, including the molecular basis for association with lipoproteins and susceptibility to oxidative inactivation. The circulating form of PAF-AH is constitutively active and its expression is upregulated by mediators of inflammation at the transcriptional level. This mechanism is likely responsible for the observed up-regulation of PAF-AH during atherosclerosis and suggests that increased expression of this enzyme is a physiological response to inflammatory stimuli. Administration of recombinant forms of PAF-AH attenuate inflammation in a variety of experimental models. Conversely, genetic deficiency of PAF-AH in defined human populations increases the severity of atherosclerosis and other syndromes. Recent advances pointing to an interplay among oxidized phospholipid substrates, Lp(a), and PAF-AH could hold the key to a number of unanswered questions.
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Affiliation(s)
- Diana M Stafforini
- Huntsman Cancer Institute and Department of Internal Medicine, University of Utah, 2000 Circle of Hope, Suite 3364, Salt Lake City, UT 84112-5550, USA.
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Bancells C, Benítez S, Villegas S, Jorba O, Ordóñez-Llanos J, Sánchez-Quesada JL. Novel phospholipolytic activities associated with electronegative low-density lipoprotein are involved in increased self-aggregation. Biochemistry 2008; 47:8186-94. [PMID: 18605697 DOI: 10.1021/bi800537h] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Electronegative low-density lipoprotein (LDL(-)) is a minor LDL subfraction present in plasma with increased platelet-activating factor acetylhydrolase (PAF-AH) activity. This activity could be involved in the proinflammatory effects of LDL(-). Our aim was to study the presence of additional phospholipolytic activities in LDL(-). Total LDL was fractionated into electropositive (LDL(+)) and LDL(-) by anion-exchange chromatography, and phospholipolytic activities were measured by fluorometric methods. Phospholipolytic activity was absent in LDL(+) whereas LDL(-) presented activity against lysophosphatidylcholine (LPC, 82.4 +/- 34.9 milliunits/mg of apoB), sphingomyelin (SM, 53.3 +/- 22.5 milliunits/mg of apoB), and phosphatidylcholine (PC, 25.7 +/- 4.3 milliunits/mg of apoB). LDL(-), but not LDL(+), presented spontaneous self-aggregation at 37 degrees C in parallel to phospholipid degradation. This was observed in the absence of lipid peroxidation and suggests the involvement of phospholipolytic activity in self-aggregation of LDL(-). Phospholipolytic activity was not due to PAF-AH, apoE, or apoC-III and was not increased in LDL(+) modified by Cu (2+) oxidation, acetylation, or secretory phospholipase A 2 (PLA 2). However, LDL(-) efficiently degraded phospholipids of lipoproteins enriched in LPC, such as oxidized LDL or PLA 2-LDL, but not native or acetylated LDL. This finding supports that LPC is the best substrate for LDL(-)-associated phospholipolytic activity. These results reveal novel properties of LDL(-) that could play a significant role in its atherogenic properties.
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Affiliation(s)
- Cristina Bancells
- Servei de Bioquímica, Institut de Recerca, Hospital de la Santa Creu i Sant Pau
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Yang CY, Chen HH, Huang MT, Raya JL, Yang JH, Chen CH, Gaubatz JW, Pownall HJ, Taylor AA, Ballantyne CM, Jenniskens FA, Smith CV. Pro-apoptotic low-density lipoprotein subfractions in type II diabetes. Atherosclerosis 2007; 193:283-91. [PMID: 17030034 DOI: 10.1016/j.atherosclerosis.2006.08.059] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2006] [Revised: 07/27/2006] [Accepted: 08/25/2006] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To test the hypothesis that differences in subfractions of circulating lipoproteins between diabetic and non-diabetic subjects exist and might contribute to the increased risk for atherosclerosis in type II diabetics. METHODS AND RESULTS LDL isolated from diabetic (D) and control subjects (N) were separated by FPLC into five subfractions (L1-L5). The fractional distributions of N- and D-LDL were not different, but the most strongly retained subfractions of D-LDL (D-L5) were markedly more pro-apoptotic to bovine aortic endothelial cells in vitro than were the other subfractions in D- or N-LDL. D-L5 induced time- and concentration-dependent apoptosis that was inhibited by z-VAD-fmk. The most electronegative D-LDL subfractions contained substantial amounts of apoproteins AI, E and CIII, higher concentrations of non-esterified fatty acids and LpPLA2, and lower trinitrobenzenesulfonic acid (TNBSA) reactivities. Electronegative subfractions of D-LDL exhibited longer lag times and lower net increases in absorbance at 234 nm with Cu-catalyzed oxidation in vitro. CONCLUSIONS The toxicities of electronegative subfractions of LDL from diabetic subjects to endothelial cells in vitro may be pivotal to vascular complications of diabetes in vivo, but the specific molecular alterations responsible for the toxicities of these subfractions of diabetic LDL are not known.
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Affiliation(s)
- Chao-yuh Yang
- Department of Medicine, Baylor College of Medicine, 6565 Fannin, MS A.601, Houston, TX 77030, USA.
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Benítez S, Pérez A, Sánchez-Quesada JL, Wagner AM, Rigla M, Arcelus R, Jorba O, Ordóñez-Llanos J. Electronegative low-density lipoprotein subfraction from type 2 diabetic subjects is proatherogenic and unrelated to glycemic control. Diabetes Metab Res Rev 2007; 23:26-34. [PMID: 16634114 DOI: 10.1002/dmrr.643] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND The physicochemical and biological characteristics of electronegative low-density lipoprotein (LDL) (LDL(-)) from type 2 diabetic patients (DM2), before and after insulin therapy, were studied. METHODS Total LDL was subfractionated in LDL(+) (native LDL) and LDL(-) by anion-exchange chromatography. RESULTS The proportion of LDL(-) was increased in plasma from DM2 patients compared to control subjects (13.8 +/- 4.6% versus 6.1 +/- 2.5, P < 0.05) and was not modified after glycemic optimization (14.0 +/- 5.9%). LDL(-) from DM2 patients presented similar differential characteristics versus LDL(+) than LDL(-) from controls; that is, decreased apoB and oxidizability, and increased triglyceride, nonesterified fatty acids (NEFA), apoE, apoC-III, platelet-activating factor (PAF) acetylhydrolase activity and aggregability. No difference in particle size, antioxidants, malondialdehyde (MDA), fructosamine or glycated low-density lipoprotein (gLDL) was observed between LDL subfractions. Concerning differences between LDL subfractions isolated from DM2 and from control subjects, the former showed increased MDA, fructosamine and gLDL proportion and decreased LDL size and antioxidant content. The only effect of glycemic optimization was a decrease in fructosamine and gLDL in LDL(+) from DM2 subjects. LDL(-) from DM2 patients presented low binding affinity to the low-density lipoprotein receptor (LDLr) in cultured fibroblasts compared to LDL(+) and two- to threefold increased ability to release interleukin-8 (IL-8) and monocyte chemotactic protein 1 (MCP-1) in endothelial cells. CONCLUSION These results suggest that, although nonenzymatic glycosylation and oxidation are increased in type 2 diabetes, these features would not be directly involved in the generation of LDL(-). Moreover, LDL(-) properties suggest that the high proportion observed in plasma could promote accelerated atherosclerosis in DM2 patients through increased residence time in plasma and induction of inflammatory responses in artery wall cells.
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Affiliation(s)
- Sónia Benítez
- Research Institute, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
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Chen HH, Hosken BD, Huang M, Gaubatz JW, Myers CL, Macfarlane RD, Pownall HJ, Yang CY. Electronegative LDLs from familial hypercholesterolemic patients are physicochemically heterogeneous but uniformly proapoptotic. J Lipid Res 2007; 48:177-84. [PMID: 17015886 DOI: 10.1194/jlr.m500481-jlr200] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A highly electronegative fraction of human plasma LDLs, designated L5, has distinctive biological activity that includes induction of apoptosis in bovine aortic endothelial cells (BAECs). This study was performed to identify a relationship between LDL density, electronegativity, and biological activity, namely, the induction of apoptosis in BAECs. Plasma LDLs from normolipidemic subjects and homozygotic familial hypercholesterolemia subjects were separated into five subfractions, with increasing electronegativity from L1 to L5, and into seven subfractions according to increasing density, D1 to D7. L1 to L5 were also separated according to density, and D1 to D7 were separated according to charge. The density profiles of L1 to L5 were similar (maximum density = 1.030 +/- 0.002 g/ml). Induction of apoptosis by all seven density subfractions was confined to the highly electronegative fraction, L5, and within each density subfraction the magnitude of apoptosis correlated with the L5 content. Electronegative LDL is heterogeneous with respect to density and composition, and induction of apoptosis is more strongly associated with LDL electronegativity than with LDL size or density.
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Affiliation(s)
- Hsin-hung Chen
- Section of Atherosclerosis and Lipoprotein Research, Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
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Gloerich J, van den Brink DM, Ruiter JPN, van Vlies N, Vaz FM, Wanders RJA, Ferdinandusse S. Metabolism of phytol to phytanic acid in the mouse, and the role of PPARα in its regulation. J Lipid Res 2007; 48:77-85. [PMID: 17015885 DOI: 10.1194/jlr.m600050-jlr200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phytol, a branched-chain fatty alcohol, is the naturally occurring precursor of phytanic and pristanic acid, branched-chain fatty acids that are both ligands for the nuclear hormone receptor peroxisome proliferator-activated receptor alpha (PPARalpha). To investigate the metabolism of phytol and the role of PPARalpha in its regulation, wild-type and PPARalpha knockout (PPARalpha-/-) mice were fed a phytol-enriched diet or, for comparison, a diet enriched with Wy-14,643, a synthetic PPARalpha agonist. After the phytol-enriched diet, phytol could only be detected in small intestine, the site of uptake, and liver. Upon longer duration of the diet, the level of the (E)-isomer of phytol increased significantly in the liver of PPARalpha-/- mice compared with wild-type mice. Activity measurements of the enzymes involved in phytol metabolism showed that treatment with a PPARalpha agonist resulted in a PPARalpha-dependent induction of at least two steps of the phytol degradation pathway in liver. Furthermore, the enzymes involved showed a higher activity toward the (E)-isomer than the (Z)-isomer of their respective substrates, indicating a stereospecificity toward the metabolism of (E)-phytol. In conclusion, the results described here show that the conversion of phytol to phytanic acid is regulated via PPARalpha and is specific for the breakdown of (E)-phytol.
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Affiliation(s)
- J Gloerich
- Laboratory of Genetic Metabolic Diseases, Department of Clinical Chemistry, Emma's Children's Hospital, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
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Gambino R, Pisu E, Pagano G, Cassader M. Low-density lipoproteins are more electronegatively charged in type 1 than in type 2 diabetes mellitus. Lipids 2006; 41:529-33. [PMID: 16981430 DOI: 10.1007/s11745-006-5001-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Multifactorial etiology is involved in premature atherosclerosis related to diabetes. Most of the mechanisms that are responsible for the etiology in diabetes have remained unsolved so far. Type 1 diabetes is associated with a favorable lipid pattern and with microangiopathy, which is not true for type 2 diabetes, which is related to dyslipidemia and macroangiopathy. The aim of this work was to evaluate the degree of LDL modification related to the types of diabetes. The question is whether the LDL could be differently modified since the pathogenesis of type 1 and type 2 diabetes is different. Thirty-one type 1 (19 male and 12 female) and thirty type 2 (18 male and 12 female) diabetic patients were included in this study. Isolated LDL was analyzed by capillary electrophoresis for diene conjugate content and for electronegativity. LDL from type 1 diabetes subjects showed the highest electrophoretic mobility (P = 0.000). Instead, the diene conjugates contents were higher in the type 2 patients with HbA1c levels > 8% (P = 0.007). In conclusion, the increased diene content in type 2 diabetic subjects in poor glycemic control and the highest LDL mobility found in type 1 subjects show that the LDL undergoes different modifications. In type 2 patients, electronegative LDL are in a state of higher susceptibility to oxidation, whereas in type 1 subjects the finding of electronegative lipoproteins could provide an index of the relative atherogenicity of circulating LDL, especially as LDL has higher electrophoretic mobility than normal subjects.
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Affiliation(s)
- R Gambino
- Department of Internal Medicine, University of Turin, Italy.
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