1
|
Akyol O, Akyol S, Chou MC, Chen S, Liu CK, Selek S, Soares JC, Chen CH. Lipids and lipoproteins may play a role in the neuropathology of Alzheimer's disease. Front Neurosci 2023; 17:1275932. [PMID: 38033552 PMCID: PMC10687420 DOI: 10.3389/fnins.2023.1275932] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 10/30/2023] [Indexed: 12/02/2023] Open
Abstract
Alzheimer's disease (AD) and other classes of dementia are important public health problems with overwhelming social, physical, and financial effects for patients, society, and their families and caregivers. The pathophysiology of AD is poorly understood despite the extensive number of clinical and experimental studies. The brain's lipid-rich composition is linked to disturbances in lipid homeostasis, often associated with glucose and lipid abnormalities in various neurodegenerative diseases, including AD. Moreover, elevated low-density lipoprotein (LDL) cholesterol levels may be related to a higher probability of AD. Here, we hypothesize that lipids, and electronegative LDL (L5) in particular, may be involved in the pathophysiology of AD. Although changes in cholesterol, triglyceride, LDL, and glucose levels are seen in AD, the cause remains unknown. We believe that L5-the most electronegative subfraction of LDL-may be a crucial factor in understanding the involvement of lipids in AD pathology. LDL and L5 are internalized by cells through different receptors and mechanisms that trigger separate intracellular pathways. One of the receptors involved in L5 internalization, LOX-1, triggers apoptotic pathways. Aging is associated with dysregulation of lipid homeostasis, and it is believed that alterations in lipid metabolism contribute to the pathogenesis of AD. Proposed mechanisms of lipid dysregulation in AD include mitochondrial dysfunction, blood-brain barrier disease, neuronal signaling, inflammation, and oxidative stress, all of which lead ultimately to memory loss through deficiency of synaptic integration. Several lipid species and their receptors have essential functions in AD pathogenesis and may be potential biomarkers.
Collapse
Affiliation(s)
- Omer Akyol
- Molecular Cardiology, Vascular and Medicinal Research, The Texas Heart Institute, Houston, TX, United States
| | | | - Mei-Chuan Chou
- Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Shioulan Chen
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ching-Kuan Liu
- Institute of Precision Medicine, College of Medicine, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Salih Selek
- Department of Psychiatry and Behavioral Sciences, UTHealth Houston McGovern Medical School, Houston, TX, United States
| | - Jair C. Soares
- Department of Psychiatry and Behavioral Sciences, UTHealth Houston McGovern Medical School, Houston, TX, United States
| | - Chu-Huang Chen
- Molecular Cardiology, Vascular and Medicinal Research, The Texas Heart Institute, Houston, TX, United States
| |
Collapse
|
2
|
Itabe H, Obama T. The Oxidized Lipoproteins In Vivo: Its Diversity and Behavior in the Human Circulation. Int J Mol Sci 2023; 24:ijms24065747. [PMID: 36982815 PMCID: PMC10053446 DOI: 10.3390/ijms24065747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 03/07/2023] [Accepted: 03/15/2023] [Indexed: 03/19/2023] Open
Abstract
A high concentration of low-density lipoproteins (LDLs) in circulation has been well-known as a major risk factor for cardiovascular diseases. The presence of oxidized LDLs (oxLDLs) in atherosclerotic lesions and circulation was demonstrated using anti-oxLDL monoclonal antibodies. The so-called “oxLDL hypothesis”, as a mechanism for atherosclerosis development, has been attracting attention for decades. However, the oxLDL has been considered a hypothetical particle since the oxLDL present in vivo has not been fully characterized. Several chemically modified LDLs have been proposed to mimic oxLDLs. Some of the subfractions of LDL, especially Lp(a) and electronegative LDL, have been characterized as oxLDL candidates as oxidized phospholipids that stimulate vascular cells. Oxidized high-density lipoprotein (oxHDL) and oxLDL were discovered immunologically in vivo. Recently, an oxLDL-oxHDL complex was found in human plasma, suggesting the involvement of HDLs in the oxidative modification of lipoproteins in vivo. In this review, we summarize our understanding of oxidized lipoproteins and propose a novel standpoint to understand the oxidized lipoproteins present in vivo.
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Ke LY, Law SH, Mishra VK, Parveen F, Chan HC, Lu YH, Chu CS. Molecular and Cellular Mechanisms of Electronegative Lipoproteins in Cardiovascular Diseases. Biomedicines 2020; 8:biomedicines8120550. [PMID: 33260304 PMCID: PMC7760527 DOI: 10.3390/biomedicines8120550] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/23/2020] [Accepted: 11/26/2020] [Indexed: 02/06/2023] Open
Abstract
Dysregulation of glucose and lipid metabolism increases plasma levels of lipoproteins and triglycerides, resulting in vascular endothelial damage. Remarkably, the oxidation of lipid and lipoprotein particles generates electronegative lipoproteins that mediate cellular deterioration of atherosclerosis. In this review, we examined the core of atherosclerotic plaque, which is enriched by byproducts of lipid metabolism and lipoproteins, such as oxidized low-density lipoproteins (oxLDL) and electronegative subfraction of LDL (LDL(−)). We also summarized the chemical properties, receptors, and molecular mechanisms of LDL(−). In combination with other well-known markers of inflammation, namely metabolic diseases, we concluded that LDL(−) can be used as a novel prognostic tool for these lipid disorders. In addition, through understanding the underlying pathophysiological molecular routes for endothelial dysfunction and inflammation, we may reassess current therapeutics and might gain a new direction to treat atherosclerotic cardiovascular diseases, mainly targeting LDL(−) clearance.
Collapse
Affiliation(s)
- Liang-Yin Ke
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 807378, Taiwan; (L.-Y.K.); (S.H.L.); (V.K.M.); (F.P.)
- Graduate Institute of Medicine, College of Medicine and Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung 807378, Taiwan
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807377, Taiwan; (H.-C.C.); (Y.-H.L.)
| | - Shi Hui Law
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 807378, Taiwan; (L.-Y.K.); (S.H.L.); (V.K.M.); (F.P.)
| | - Vineet Kumar Mishra
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 807378, Taiwan; (L.-Y.K.); (S.H.L.); (V.K.M.); (F.P.)
| | - Farzana Parveen
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 807378, Taiwan; (L.-Y.K.); (S.H.L.); (V.K.M.); (F.P.)
| | - Hua-Chen Chan
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807377, Taiwan; (H.-C.C.); (Y.-H.L.)
| | - Ye-Hsu Lu
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807377, Taiwan; (H.-C.C.); (Y.-H.L.)
- Division of Cardiology, Department of International Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807377, Taiwan
| | - Chih-Sheng Chu
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807377, Taiwan; (H.-C.C.); (Y.-H.L.)
- Division of Cardiology, Department of International Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807377, Taiwan
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung 80145, Taiwan
- Correspondence: ; Tel.: +886-73121101 (ext. 2297); Fax: +886-73111996
| |
Collapse
|
5
|
Chu CS, Law SH, Lenzen D, Tan YH, Weng SF, Ito E, Wu JC, Chen CH, Chan HC, Ke LY. Clinical Significance of Electronegative Low-Density Lipoprotein Cholesterol in Atherothrombosis. Biomedicines 2020; 8:biomedicines8080254. [PMID: 32751498 PMCID: PMC7460408 DOI: 10.3390/biomedicines8080254] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/25/2020] [Accepted: 07/28/2020] [Indexed: 02/06/2023] Open
Abstract
Despite the numerous risk factors for atherosclerotic cardiovascular diseases (ASCVD), cumulative evidence shows that electronegative low-density lipoprotein (L5 LDL) cholesterol is a promising biomarker. Its toxicity may contribute to atherothrombotic events. Notably, plasma L5 LDL levels positively correlate with the increasing severity of cardiovascular diseases. In contrast, traditional markers such as LDL-cholesterol and triglyceride are the therapeutic goals in secondary prevention for ASCVD, but that is controversial in primary prevention for patients with low risk. In this review, we point out the clinical significance and pathophysiological mechanisms of L5 LDL, and the clinical applications of L5 LDL levels in ASCVD can be confidently addressed. Based on the previously defined cut-off value by receiver operating characteristic curve, the acceptable physiological range of L5 concentration is proposed to be below 1.7 mg/dL. When L5 LDL level surpass this threshold, clinically relevant ASCVD might be present, and further exams such as carotid intima-media thickness, pulse wave velocity, exercise stress test, or multidetector computed tomography are required. Notably, the ultimate goal of L5 LDL concentration is lower than 1.7 mg/dL. Instead, with L5 LDL greater than 1.7 mg/dL, lipid-lowering treatment may be required, including statin, ezetimibe or PCSK9 inhibitor, regardless of the low-density lipoprotein cholesterol (LDL-C) level. Since L5 LDL could be a promising biomarker, we propose that a high throughput, clinically feasible methodology is urgently required not only for conducting a prospective, large population study but for developing therapeutics strategies to decrease L5 LDL in the blood.
Collapse
Affiliation(s)
- Chih-Sheng Chu
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807377, Taiwan;
- Division of Cardiology, Department of International Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807377, Taiwan
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung 80145, Taiwan
| | - Shi Hui Law
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 807378, Taiwan; (S.H.L.); (D.L.); (Y.-H.T.); (E.I.)
| | - David Lenzen
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 807378, Taiwan; (S.H.L.); (D.L.); (Y.-H.T.); (E.I.)
| | - Yong-Hong Tan
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 807378, Taiwan; (S.H.L.); (D.L.); (Y.-H.T.); (E.I.)
| | - Shih-Feng Weng
- Department of Healthcare Administration and Medical Informatics, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 807378, Taiwan;
| | - Etsuro Ito
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 807378, Taiwan; (S.H.L.); (D.L.); (Y.-H.T.); (E.I.)
- Department of Biology, Waseda University, Tokyo 162-8480, Japan
- Waseda Research Institute for Science and Engineering, Waseda University, Tokyo 162-8480, Japan
| | - Jung-Chou Wu
- Division of Cardiology, Department of Internal Medicine, Pingtung Christian Hospital, Pingtung 90059, Taiwan;
| | - Chu-Huang Chen
- Vascular and Medicinal Research, Texas Heart Institute, Houston, TX 77030, USA;
| | - Hua-Chen Chan
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807377, Taiwan;
- Correspondence: (H.-C.C.); (L.-Y.K.); Tel.: +886-73121101 (ext. 2296); Fax: +886-73111996 (L.-Y.K.)
| | - Liang-Yin Ke
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 807378, Taiwan; (S.H.L.); (D.L.); (Y.-H.T.); (E.I.)
- Graduate Institute of Medicine, College of Medicine, & Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung 807378, Taiwan
- Correspondence: (H.-C.C.); (L.-Y.K.); Tel.: +886-73121101 (ext. 2296); Fax: +886-73111996 (L.-Y.K.)
| |
Collapse
|
6
|
Sawada N, Obama T, Koba S, Takaki T, Iwamoto S, Aiuchi T, Kato R, Kikuchi M, Hamazaki Y, Itabe H. Circulating oxidized LDL, increased in patients with acute myocardial infarction, is accompanied by heavily modified HDL. J Lipid Res 2020; 61:816-829. [PMID: 32291330 PMCID: PMC7269762 DOI: 10.1194/jlr.ra119000312] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 03/13/2020] [Indexed: 12/13/2022] Open
Abstract
Oxidized LDL (oxLDL) is a known risk factor for atherogenesis. This study aimed to reveal structural features of oxLDL present in human circulation related to atherosclerosis. When LDL was fractionated on an anion-exchange column, in vivo-oxLDL, detected by the anti-oxidized PC (oxPC) mAb, was recovered in flow-through and electronegative LDL [LDL(-)] fractions. The amount of the electronegative in vivo-oxLDL, namely oxLDL in the LDL(-) fraction, present in patients with acute MI was 3-fold higher than that observed in healthy subjects. Surprisingly, the LDL(-) fraction contained apoA1 in addition to apoB, and HDL-sized particles were observed with transmission electron microscopy. In LDL(-) fractions, acrolein adducts were identified at all lysine residues in apoA1, with only a small number of acrolein-modified residues identified in apoB. The amount of oxPC adducts of apoB was higher in the LDL(-) than in the L1 fraction, as determined using Western blotting. The electronegative in vivo-oxLDL was immunologically purified from the LDL(-) fraction with an anti-oxPC mAb. The majority of PC species were not oxidized, whereas oxPC and lysoPC did not accumulate. Here, we propose that there are two types of in vivo-oxLDL in human circulating plasma and the electronegative in vivo-oxLDL accompanies oxidized HDL.
Collapse
Affiliation(s)
- Naoko Sawada
- Division of Biological Chemistry, Department of Pharmaceutical Sciences Showa University School of Pharmacy, Shinagawa-ku, Tokyo 142-8555, Japan
| | - Takashi Obama
- Division of Biological Chemistry, Department of Pharmaceutical Sciences Showa University School of Pharmacy, Shinagawa-ku, Tokyo 142-8555, Japan
| | - Shinji Koba
- Division of Cardiology, Department of Medicine Showa University School of Medicine, Shinagawa-ku, Tokyo 142-8555, Japan
| | - Takashi Takaki
- Division of Electron Microscopy Showa University School of Medicine, Shinagawa-ku, Tokyo 142-8555, Japan
| | - Sanju Iwamoto
- Division of Physiology and Pathology, Department of Pharmacology, Toxicology, and Therapeutics Showa University School of Pharmacy, Shinagawa-ku, Tokyo 142-8555, Japan
| | - Toshihiro Aiuchi
- Division of Biological Chemistry, Department of Pharmaceutical Sciences Showa University School of Pharmacy, Shinagawa-ku, Tokyo 142-8555, Japan
| | - Rina Kato
- Division of Biological Chemistry, Department of Pharmaceutical Sciences Showa University School of Pharmacy, Shinagawa-ku, Tokyo 142-8555, Japan
| | - Masaki Kikuchi
- Division of Biological Chemistry, Department of Pharmaceutical Sciences Showa University School of Pharmacy, Shinagawa-ku, Tokyo 142-8555, Japan
| | - Yuji Hamazaki
- Division of Cardiology, Department of Medicine Showa University School of Medicine, Shinagawa-ku, Tokyo 142-8555, Japan
| | - Hiroyuki Itabe
- Division of Biological Chemistry, Department of Pharmaceutical Sciences Showa University School of Pharmacy, Shinagawa-ku, Tokyo 142-8555, Japan. mailto:
| |
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Yang TC, Chang PY, Kuo TL, Lu SC. Electronegative L5-LDL induces the production of G-CSF and GM-CSF in human macrophages through LOX-1 involving NF-κB and ERK2 activation. Atherosclerosis 2017; 267:1-9. [PMID: 29078142 DOI: 10.1016/j.atherosclerosis.2017.10.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 09/30/2017] [Accepted: 10/12/2017] [Indexed: 12/17/2022]
Abstract
BACKGROUND AND AIMS Circulating levels of granulocyte colony-stimulating factor (G-CSF) and granulocyte macrophage colony-stimulating factor (GM-CSF) are associated with the severity of acute myocardial infarction (AMI). However, what causes increases in G-CSF and GM-CSF is unclear. In this study, we investigated whether L5-low-density lipoprotein (LDL), a mildly oxidized LDL from AMI, can induce G-CSF and GM-CSF production in human macrophages. METHODS L1-LDL and L5-LDL were isolated through anion-exchange chromatography from AMI plasma. Human macrophages derived from THP-1 and peripheral blood mononuclear cells were treated with L1-LDL, L5-LDL, or copper-oxidized LDL (Cu-oxLDL) and G-CSF and GM-CSF protein levels in the medium were determined. In addition, the effects of L5-LDL on G-CSF and GM-CSF production were tested in lectin-type oxidized LDL receptor-1 (LOX-1), CD36, extracellular signal-regulated kinase (ERK) 1, and ERK2 knockdown THP-1 macrophages. RESULTS L5-LDL but not L1-LDL or Cu-oxLDL significantly induced production of G-CSF and GM-CSF in macrophages. In vitro oxidation of L1-LDL and L5-LDL altered their ability to induce G-CSF and GM-CSF, suggesting that the degree of oxidation is critical for the effects. Knockdown and antibody neutralization experiments suggested that the effects were caused by LOX-1. In addition, nuclear factor (NF)-κB and ERK1/2 inhibition resulted in marked reductions of L5-LDL-induced G-CSF and GM-CSF production. Moreover, knockdown of ERK2, but not ERK1, hindered L5-LDL-induced G-CSF and GM-CSF production. CONCLUSIONS The results indicate that L5-LDL, a naturally occurring mild oxidized LDL, induced G-CSF and GM-CSF production in human macrophages through LOX-1, ERK2, and NF-κB dependent pathways.
Collapse
Affiliation(s)
- Tzu-Ching Yang
- Department of Biochemistry and Molecular Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Po-Yuan Chang
- Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University College of Medicine, Taipei, Taiwan.
| | - Tzu-Ling Kuo
- Department of Biochemistry and Molecular Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Shao-Chun Lu
- Department of Biochemistry and Molecular Biology, National Taiwan University College of Medicine, Taipei, Taiwan.
| |
Collapse
|
9
|
Sukhorukov VN, Karagodin VP, Orekhov AN. [Atherogenic modification of low-density lipoproteins]. BIOMEDIT︠S︡INSKAI︠A︡ KHIMII︠A︡ 2017; 62:391-402. [PMID: 27562992 DOI: 10.18097/pbmc20166204391] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
One of the first manifestations of atherosclerosis is accumulation of extra- and intracellular cholesterol esters in the arterial intima. Formation of foam cells is considered as a trigger in the pathogenesis of atherosclerosis. Low density lipoprotein (LDL) circulating in human blood is the source of lipids accumulated in the arterial walls. This review considered features and role in atherogenesis different modified forms of LDL: oxidized, small dense, electronegative and especially desialylated LDL. Desialylated LDL of human blood plasma is capable to induce lipid accumulation in cultured cells and it is atherogenic. LDL possesses numerous alterations of protein, carbohydrate and lipid moieties and therefore can be termed multiple-modified LDL. Multiple modification of LDL occurs in human blood plasma and represents a cascade of successive changes in the lipoprotein particle: desialylation, loss of lipids, reduction in the particle size, increase of surface electronegative charge, etc. In addition to intracellular lipid accumulation, stimulatory effects of naturally occurring multiple-modified LDL on other processes involved in the development of atherosclerotic lesions, namely cell proliferation and fibrosis, were shown.
Collapse
Affiliation(s)
- V N Sukhorukov
- Institute of General Pathology and Pathophysiology, Moscow, Russia
| | - V P Karagodin
- Plekhanov Russian University of Economics, Moscow, Russia
| | - A N Orekhov
- Institute of General Pathology and Pathophysiology, Moscow, Russia; Institute for Atherosclerosis Research, Skolkovo Innovative Center, PO Box #21, Moscow, Russia
| |
Collapse
|
10
|
Li S, Xu D, Guo J, Sun Y. Inhibition of cell growth and induction of inflammation by endosulfan in HUVEC-C cells. ENVIRONMENTAL TOXICOLOGY 2016; 31:1785-1795. [PMID: 26714676 DOI: 10.1002/tox.22180] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 07/13/2015] [Accepted: 07/16/2015] [Indexed: 06/05/2023]
Abstract
Endosulfan is one of the organochlorine pesticides. It has been associated with a wide range of adverse health effects. However, it is unknown whether endosulfan causes endothelial dysfunction. In the present study, we investigated the effects of endosulfan on human vascular endothelial cells. We exposed human umbilical vein endothelial cells (HUVEC-C) to varying concentrations of endosulfan for 48 h. The results showed that endosulfan lowered cell viability and inhibited cell proliferation in a dose-dependent manner. Flow cytometric analysis showed that endosulfan at 60 μM induced G1 cell cycle arrest, a response attributed to down-regulation of CDK6 and pRb dephosphorylation. We observed that endosulfan at 40 and 60 μM induced a considerable percentage of cells to undergo apoptosis, as detected by Annexin-V binding assays. Endosulfan reduced mitochondrial transmembrane potential, leading to the release of cytochrome c into the cytoplasm; meanwhile, endosulfan also inhibited the mRNA expression level of survivin, which resulted in the activation of caspase-3. These results indicated that the intrinsic mitochondria-mediated pathway was involved in apoptotic process. Exposure to endosulfan increased the secretion and mRNA expression levels of inflammation factors interleukin (IL)-6 and IL-8, suggesting that endosulfan could cause inflammation. Overall, these findings suggested that endosulfan is toxic to HUVEC-C cells, resulting in endothelial dysfunction. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1785-1795, 2016.
Collapse
Affiliation(s)
- Shuai Li
- Institute of Environmental Systems Biology, Environment Science and Engineering College, Dalian Maritime University, Linghai Road 1, Dalian, 116026, Poeple's Republic of China
| | - Dan Xu
- Institute of Environmental Systems Biology, Environment Science and Engineering College, Dalian Maritime University, Linghai Road 1, Dalian, 116026, Poeple's Republic of China
| | - Jianguo Guo
- Institute of Environmental Systems Biology, Environment Science and Engineering College, Dalian Maritime University, Linghai Road 1, Dalian, 116026, Poeple's Republic of China
| | - Yeqing Sun
- Institute of Environmental Systems Biology, Environment Science and Engineering College, Dalian Maritime University, Linghai Road 1, Dalian, 116026, Poeple's Republic of China
| |
Collapse
|
11
|
Ivanova EA, Bobryshev YV, Orekhov AN. LDL electronegativity index: a potential novel index for predicting cardiovascular disease. Vasc Health Risk Manag 2015; 11:525-32. [PMID: 26357481 PMCID: PMC4559248 DOI: 10.2147/vhrm.s74697] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
High cardiovascular risk conditions are frequently associated with altered plasma lipoprotein profile, such as elevated low-density lipoprotein (LDL) and LDL cholesterol and decreased high-density lipoprotein. There is, however, accumulating evidence that specific subclasses of LDL may play an important role in cardiovascular disease development, and their relative concentration can be regarded as a more relevant risk factor. LDL particles undergo multiple modifications in plasma that can lead to the increase of their negative charge. The resulting electronegative LDL [LDL(–)] subfraction has been demonstrated to be especially atherogenic, and became a subject of numerous recent studies. In this review, we discuss the physicochemical properties of LDL(–), methods of its detection, atherogenic activity, and relevance of the LDL electronegativity index as a potential independent predictor of cardiovascular risk.
Collapse
Affiliation(s)
- Ekaterina A Ivanova
- Department of Pediatric Nephrology and Growth and Regeneration, Katholieke Universiteit Leuven and University Hospitals Leuven, Leuven, Belgium
| | - Yuri V Bobryshev
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Russian Academy of Sciences, Moscow, Russia ; Faculty of Medicine, School of Medical Sciences, University of New South Wales, Kensington, Sydney, NSW, Australia
| | - Alexander N Orekhov
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Russian Academy of Sciences, Moscow, Russia ; Institute for Atherosclerosis Research, Skolkovo Innovative Center, Moscow, Russia ; Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| |
Collapse
|
12
|
He XD, Wu Q, Liu W, Hong T, Li JJ, Miao RY, Zhao HT. Association of metabolic syndromes and risk factors with ampullary tumors development: A case-control study in China. World J Gastroenterol 2014; 20:9541-9548. [PMID: 25071350 PMCID: PMC4110587 DOI: 10.3748/wjg.v20.i28.9541] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 02/22/2014] [Accepted: 05/19/2014] [Indexed: 02/06/2023] Open
Abstract
AIM: To evaluate the risk factors for ampullary adenoma and ampullary cancer.
METHODS: This case-control study included ampullary tumor patients referred to Peking Union Medical College Hospital. Controls were randomly selected from an existing database of healthy individuals at the Health Screening Center of the same hospital. Data on metabolic syndromes, medical conditions, and family history were collected by retrospective review of the patients’ records and health examination reports, or by interview.
RESULTS: A total of 181 patients and 905 age- and sex-matched controls were enrolled. We found that a history of diabetes, cholecystolithiasis, low-density lipoprotein, and apolipoprotein A were significantly related to ampullary adenomas. Diabetes, cholecystolithiasis, chronic pancreatitis, total cholesterol, high-density lipoprotein, and apolipoprotein A were also significantly related to ampullary cancer.
CONCLUSION: Some metabolic syndrome components and medical conditions are potential risk factors for the development of ampullary tumors. Cholelithiasis, diabetes, and apolipoprotein A may contribute to the malignant transformation of benign ampullary adenomas into ampullary cancer.
Collapse
|
13
|
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.
Collapse
|
14
|
Estruch M, Bancells C, Beloki L, Sanchez-Quesada JL, Ordóñez-Llanos J, Benitez S. CD14 and TLR4 mediate cytokine release promoted by electronegative LDL in monocytes. Atherosclerosis 2013; 229:356-62. [PMID: 23880187 DOI: 10.1016/j.atherosclerosis.2013.05.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 04/17/2013] [Accepted: 05/10/2013] [Indexed: 10/26/2022]
Abstract
AIMS Electronegative LDL (LDL(-)), a minor modified LDL present in the circulation, induces cytokine release in monocytes. We aimed to determine the role of the receptor CD14 and toll-like receptors 2 and 4 (TLR2, TLR4) in the inflammatory action promoted by LDL(-) in human monocytes. METHODS AND RESULTS Monocytes were preincubated with antibodies to neutralize CD14, TLR2 and TLR4. The release of monocyte chemoattractant protein 1 (MCP1), and interleukin 6 and 10 (IL6 and IL10) promoted by LDL(-) was inhibited 70-80% by antiCD14 and antiTLR4, and 15-25% by antiTLR2. The involvement of CD14 and TLR4 was confirmed by gene silencing experiments. The human monocytic THP1 cell line overexpressing CD14 released more cytokines in response to LDL(-) than the same THP1 cell line without expressing CD14. VIPER, a specific inhibitor of the TLR4 signaling pathway, blocked 75-90% the cytokine release promoted by LDL(-). Cell binding experiments showed that monocytes preincubated with neutralizing antibodies presented lesser LDL(-) binding than non-preincubated monocytes The inhibitory capacity was antiCD14>antiTLR4>>antiTLR2. Cell-free experiments performed in CD14-coated microtiter wells confirmed that CD14 was involved in LDL(-) binding. When LDL(-) and lipopolysaccharide (LPS) were added simultaneously to monocytes, cytokine release was similar to that promoted by LDL(-) alone. Binding experiments showed that LDL(-) and LPS competed for binding to monocytes and to CD14 coated-wells. CONCLUSIONS CD14 and TLR4 mediate cytokine release induced by LDL(-) in human monocytes. The cross-competition between LPS and LDL(-) for the same receptors could be a counteracting action of LDL(-) in inflammatory situations.
Collapse
Affiliation(s)
- Montserrat Estruch
- Instituto de Investigaciones Biomédicas Sant Pau (IIB SantPau), Barcelona, Spain.
| | | | | | | | | | | |
Collapse
|
15
|
Lobo JC, Stockler-Pinto MB, Farage NE, Faulin TDES, Abdalla DSP, Torres JPM, Velarde LGC, Mafra D. Reduced plasma zinc levels, lipid peroxidation, and inflammation biomarkers levels in hemodialysis patients: implications to cardiovascular mortality. Ren Fail 2013; 35:680-5. [PMID: 23650973 DOI: 10.3109/0886022x.2013.789960] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Despite the fact that low plasma zinc (Zn) levels play important roles in the oxidative stress, the relationships between lipid peroxidation and inflammation biomarkers with low plasma Zn levels have not been investigated in chronic kidney disease (CKD) patients. The aim of this study was to evaluate the Zn plasma levels, electronegative LDL [LDL(-)] levels, and inflammation markers as predictors of cardiovascular (CV) mortality in hemodialysis (HD) patients. Forty-five HD patients (28 men, 54.2 ± 12.7 years, 62.2 ± 51.4 months on dialysis and BMI 24.3 ± 4.1 kg/m(2)) were studied and compared to 20 healthy individuals (9 men, 51.6 ± 15.6 years, BMI 25.2 ± 3.9 kg/m(2)) and followed for 24 months to investigate the risks for CV mortality. LDL(-) levels were measured by ELISA, plasma Zn levels by atomic absorption spectrophotometry, C-reactive protein (CRP) level by immunoturbidimetric method, and tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), monocyte chemotactic protein-1 (MCP-1), and plasminogen activator inhibitor-1 (PAI-1) levels by a multiplex assay kit. HD patients presented low plasma Zn levels (54.9 ± 16.1 μg/dL) and high-LDL(-) (0.18 ± 0.12 U/L) and TNF-α (5.5 ± 2.2 pg/mL) levels when compared to healthy subjects (78.8 ± 9.4μ g/dL, 0.10 ± 0.08U/L, 2.4 ± 1.1 pg/mL, respectively, p < 0.05). Zn plasma levels were negatively correlated to TNF-α (r = -0.49; p = 0.0001) and LDL(-) (r = -0.33; p = 0.008). During the 2 years, 24.4% of the patients died, all due to CV disease. Analysis by the Cox model showed that high CRP, TNF-α, IL-6 levels, and long duration of HD were significant predictors of mortality. In conclusion, reduced Zn levels were associated with lipid peroxidation and inflammation, and we confirm here in a Brazilian cohort of HD patients that inflammation markers are strong predictors of CV death.
Collapse
Affiliation(s)
- Julie Calixto Lobo
- Institute of Biophysic Carlos Chagas Filho, Health Sciense Centre, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
| | | | | | | | | | | | | | | |
Collapse
|
16
|
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
| |
Collapse
|
17
|
The Induction of Cytokine Release in Monocytes by Electronegative Low-Density Lipoprotein (LDL) Is Related to Its Higher Ceramide Content than Native LDL. Int J Mol Sci 2013; 14:2601-16. [PMID: 23358250 PMCID: PMC3588005 DOI: 10.3390/ijms14022601] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 01/05/2013] [Accepted: 01/16/2013] [Indexed: 12/21/2022] Open
Abstract
Electronegative low-density lipoprotein (LDL(−)) is a minor modified LDL subfraction that is present in blood. LDL(−) promotes inflammation and is associated with the development of atherosclerosis. We previously reported that the increase of cytokine release promoted by this lipoprotein subfraction in monocytes is counteracted by high-density lipoprotein (HDL). HDL also inhibits a phospholipase C-like activity (PLC-like) intrinsic to LDL(−). The aim of this work was to assess whether the inhibition of the PLC-like activity by HDL could decrease the content of ceramide (CER) and diacylglycerol (DAG) generated in LDL(−). This knowledge would allow us to establish a relationship between these compounds and the inflammatory activity of LDL(−). LDL(−) incubated at 37 °C for 20 h increased its PLC-like activity and, subsequently, the amount of CER and DAG. We found that incubating LDL(−) with HDL decreased both products in LDL(−). Native LDL was modified by lipolysis with PLC or by incubation with CER-enriched or DAG-enriched liposomes. The increase of CER in native LDL significantly increased cytokine release, whereas the enrichment in DAG did not show these inflammatory properties. These data point to CER, a resultant product of the PLC-like activity, as a major determinant of the inflammatory activity induced by LDL(−) in monocytes.
Collapse
|
18
|
Wu Q, He XD, Yu L, Liu W, Tao LY. The metabolic syndrome and risk factors for biliary tract cancer: a case-control study in China. Asian Pac J Cancer Prev 2013; 13:1963-9. [PMID: 22901155 DOI: 10.7314/apjcp.2012.13.5.1963] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
OBJECTIVES Recent data show that the metabolic syndrome may play a role in several cancers, but the etiology for biliary tract cancer is incompletely defined. The present aim was to evaluate risk factors for biliary tract cancer in China. METHODS A case-control study in which cases were biliary tract cancer patients referred to Peking Union Medical College Hospital (PUMCH). Controls were randomly selected from an existing database of healthy individuals at the Health Screening Center of PUMCH. Data on the metabolic syndrome, liver diseases, family history, and history of diabetes and hypertension were collected by retrospective review of the patients' records and health examination reports or by interview. RESULTS A total of 281 patients (102 intrahepatic cholangiocarcinoma (ICC), 86 extrahepatic cholangiocarcinoma (ECC) and 93 gallbladder carcinoma (GC)) and 835 age- and sex-matched controls were enrolled. HBsAg+/anti-HBc+ (P=0.002), history of diabetes (P=0.000), cholelithiasis (P=0.000), TC (P=0.003), and HDL (P=0.000) were significantly related to ICC. Cholelithiasis (P=0.000), Tri (P=0.001), LDL (P=0.000), diabetes (P=0.000), Apo A (P=0.000) and Apo B (P=0.012) were significantly associated with ECC. Diabetes (P=0.017), cholelithiasis (P=0.000) and Apo A (P=0.000) were strongly inversely correlated with GC. CONCLUSION Cholelithiasis, HBV infection and metabolic symptoms may be potential risk factors for the development of biliary tract cancer.
Collapse
Affiliation(s)
- Qiao Wu
- Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | | | | | | | | |
Collapse
|
19
|
Sánchez-Quesada JL, Villegas S, Ordóñez-Llanos J. Electronegative low-density lipoprotein. A link between apolipoprotein B misfolding, lipoprotein aggregation and proteoglycan binding. Curr Opin Lipidol 2012; 23:479-86. [PMID: 22964994 DOI: 10.1097/mol.0b013e328357c933] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW Subendothelial retention of lipoproteins is considered the first step in the development of atherosclerosis, but the molecular mechanisms involved are poorly understood. Recent findings on the atherogenic properties of a minor electronegative fraction of LDL (LDL(-)) could contribute to a better understanding of this process. RECENT FINDINGS Circular dichroism, Trp-fluorescence and two-dimensional nuclear magnetic resonance have shown that apolipoprotein B (apoB) in LDL(-) has an abnormal, misfolded conformation. Immunochemical analysis revealed a different conformation, mainly in the N-terminal and C-terminal extremes. These alterations contribute to the high susceptibility to aggregation of LDL(-). Moreover, LDL(-) can seed the aggregation of native LDL, suggesting an amyloidogenic character that has been attributed to the amphipathic helix cluster in the α2-domain. A phospholipase C (PLC)-like activity associated to LDL(-) seems to play a major role in the LDL(-)-induced aggregation. The aggregation of LDL(-) increases its binding to proteoglycans because of the abnormal conformation of the N-terminal extreme of apoB. SUMMARY LDL(-) could play a relevant role in atherogenesis by acting as a priming factor that stimulates lipoprotein aggregation. This process, which appears to be mediated by a PLC-like activity intrinsic to LDL(-), increases the binding of LDL to proteoglycans and could promote subendothelial retention of these lipoproteins.
Collapse
Affiliation(s)
- José L Sánchez-Quesada
- Biochemistry Department, Biomedical Research Institute Sant Pau (IIB Sant Pau), Barcelona, Spain.
| | | | | |
Collapse
|
20
|
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]
|
21
|
Leal VO, Lobo JC, Stockler-Pinto MB, Farage NE, Abdalla DSP, Leite M, Mafra D. Is zinc-α2-glycoprotein a cardiovascular protective factor for patients undergoing hemodialysis? Clin Chim Acta 2011; 413:616-9. [PMID: 22178218 DOI: 10.1016/j.cca.2011.12.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 12/02/2011] [Accepted: 12/06/2011] [Indexed: 11/28/2022]
Abstract
BACKGROUND Zinc-α2-glycoprotein (ZAG) is a lipid mobilizing factor. Its anti-inflammatory action and expression pattern suggest that ZAG could act by protecting against the obesity-associated disorders. In hemodialysis (HD) patients, ZAG levels were described to be elevated but its effects on markers of inflammation and LDL oxidation are still unclear. We investigated the relationship between ZAG and markers of systemic inflammation and LDL atherogenic modification profile in HD patients. METHODS Forty-three patients regularly on HD were studied and compared to 20 healthy subjects. Plasma ZAG, adiponectin, electronegative LDL [LDL(-)], an atherosclerotic negatively charged LDL subfraction, and anti-LDL(-) autoantibodies levels were measured by ELISA. Markers of inflammation and atherogenic cell recruitment (TNF-α, interleukin-6, VCAM-1, ICAM-1, MCP-1 and PAI-1) were also determined. RESULTS Inflammatory markers and atherogenic cell recruitment were higher in HD patients when compared to healthy subjects. ZAG levels were also higher in HD patients (151.5 ± 50.1 mg/l vs 54.6 ± 23.0 mg/l; p<0.0001) and its levels were negatively correlated with TNF-α (r=-0.39; p=0.001) and VCAM-1 (r=-0.52; p<0.0001) and, positively correlated with anti-LDL(-) autoantibodies (r=0.38; p=0.016). On multivariate analyses, plasma ZAG levels were independently associated with VCAM-1 (p=0.01). CONCLUSION ZAG is inversely associated with markers of pro-atherogenic factors linked to systemic inflammation and oxidative stress. Thus, this adipokine may constitute a novel marker of a favorable metabolic profile regarding cardiovascular risk factors in HD population.
Collapse
Affiliation(s)
- Viviane O Leal
- Pós-graduação em Ciências Médicas, Universidade Federal Fluminense, Niterói, RJ, Brazil.
| | | | | | | | | | | | | |
Collapse
|
22
|
Kleinedler JJ, Orchard EA, Foley JD, Rogers LK, Hebert VY, Dugas TR. A dietary approach to increase in-stent stenosis and face validity of a rat model for arterial angioplasty and stenting. Atherosclerosis 2011; 219:484-91. [DOI: 10.1016/j.atherosclerosis.2011.09.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Revised: 08/18/2011] [Accepted: 09/13/2011] [Indexed: 11/25/2022]
|
23
|
Faulin TDES, de Sena-Evangelista KCM, Pacheco DB, Augusto EM, Abdalla DSP. Development of immunoassays for anti-electronegative LDL autoantibodies and immune complexes. Clin Chim Acta 2011; 413:291-7. [PMID: 22037508 DOI: 10.1016/j.cca.2011.10.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Revised: 10/05/2011] [Accepted: 10/06/2011] [Indexed: 11/18/2022]
Abstract
BACKGROUND Electronegative low-density lipoprotein (LDL-) promotes atherosclerosis through inflammatory and immunologic mechanisms that lead to the production of anti-LDL(-) autoantibodies and to the subsequent formation of immune complexes (IC) and macrophage foam cells. We described the development and validation of an ELISA for the quantification of free anti-LDL(-) autoantibodies and an ELISA for the quantification of IC consisting of LDL(-)-bound IgG in human plasma. METHODS LDL(-) purified from human plasma, and anti-LDL(-) monoclonal antibody Fab fragments were adsorbed onto ELISA plates to capture anti-LDL(-) autoantibodies and IC-LDL(-), respectively. The performance characteristics of both ELISAs, including the limits of detection and quantification, accuracy and inter- and intra-assay precision were evaluated. Linearity, interference and stability tests were also performed. RESULTS The calibration range of the anti-LDL(-) assay was 0.004-0.125 mU/l and plasma demonstrated a dilutional linearity when diluted 1:100, 1:200, 1:400 and 1:800. The calibration range of the IC-LDL(-) assay was 0.06-4 U/l, and plasma demonstrated a dilutional linearity when diluted 1:12.5, 1:25, 1:50 and 1:100. Both ELISAs showed intra- and inter-assay precision and recovery within the required limits for immunoassays. CONCLUSION These ELISAs can be used in clinical studies and for the biochemical investigation of atherosclerosis. In addition, they will enable the comprehensive evaluation of the importance of bound or free autoantibodies against LDL(-) in this disease.
Collapse
|
24
|
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]
|
25
|
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]
|
26
|
Bancells C, Benítez S, Ordóñez-Llanos J, Öörni K, Kovanen PT, Milne RW, Sánchez-Quesada JL. Immunochemical analysis of the electronegative LDL subfraction shows that abnormal N-terminal apolipoprotein B conformation is involved in increased binding to proteoglycans. J Biol Chem 2010; 286:1125-33. [PMID: 21078674 DOI: 10.1074/jbc.m110.175315] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Electronegative LDL (LDL(-)) is a minor subfraction of modified LDL present in plasma. Among its atherogenic characteristics, low affinity to the LDL receptor and high binding to arterial proteoglycans (PGs) could be related to abnormalities in the conformation of its main protein, apolipoprotein B-100 (apoB-100). In the current study, we have performed an immunochemical analysis using monoclonal antibody (mAb) probes to analyze the conformation of apoB-100 in LDL(-). The study, performed with 28 anti-apoB-100 mAbs, showed that major differences of apoB-100 immunoreactivity between native LDL and LDL(-) concentrate in both terminal extremes. The mAbs Bsol 10, Bsol 14 (which recognize the amino-terminal region), Bsol 2, and Bsol 7 (carboxyl-terminal region) showed increased immunoreactivity in LDL(-), suggesting that both terminal extremes are more accessible in LDL(-) than in native LDL. The analysis of in vitro-modified LDLs, including LDL lipolyzed with sphingomyelinase (SMase-LDL) or phospholipase A(2) (PLA(2)-LDL) and oxidized LDL (oxLDL), suggested that increased amino-terminal immunoreactivity was related to altered conformation due to aggregation. This was confirmed when the aggregated subfractions of LDL(-) (agLDL(-)) and oxLDL (ag-oxLDL) were isolated and analyzed. Thus, Bsol 10 and Bsol 14 immunoreactivity was high in SMase-LDL, ag-oxLDL, and agLDL(-). The altered amino-terminal apoB-100 conformation was involved in the increased PG binding affinity of agLDL(-) because Bsol 10 and Bsol 14 blocked its high PG-binding. These observations suggest that an abnormal conformation of the amino-terminal region of apoB-100 is responsible for the increased PG binding affinity of agLDL(-).
Collapse
Affiliation(s)
- Cristina Bancells
- Biochemistry Department, Biomedical Research Institute Sant Pau, Hospital de la Santa Creu i Sant Pau, 08025 Barcelona, Catalonia, Spain.
| | | | | | | | | | | | | |
Collapse
|
27
|
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]
|
28
|
Bancells C, Villegas S, Blanco FJ, Benítez S, Gállego I, Beloki L, Pérez-Cuellar M, Ordóñez-Llanos J, Sánchez-Quesada JL. Aggregated electronegative low density lipoprotein in human plasma shows a high tendency toward phospholipolysis and particle fusion. J Biol Chem 2010; 285:32425-35. [PMID: 20670941 DOI: 10.1074/jbc.m110.139691] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Aggregation and fusion of lipoproteins trigger subendothelial retention of cholesterol, promoting atherosclerosis. The tendency of a lipoprotein to form fused particles is considered to be related to its atherogenic potential. We aimed to isolate and characterize aggregated and nonaggregated subfractions of LDL from human plasma, paying special attention to particle fusion mechanisms. Aggregated LDL was almost exclusively found in electronegative LDL (LDL(-)), a minor modified LDL subfraction, but not in native LDL (LDL(+)). The main difference between aggregated (agLDL(-)) and nonaggregated LDL(-) (nagLDL(-)) was a 6-fold increased phospholipase C-like activity in agLDL(-). agLDL(-) promoted the aggregation of LDL(+) and nagLDL(-). Lipoprotein fusion induced by α-chymotrypsin proteolysis was monitored by NMR and visualized by transmission electron microscopy. Particle fusion kinetics was much faster in agLDL(-) than in nagLDL(-) or LDL(+). NMR and chromatographic analysis revealed a rapid and massive phospholipid degradation in agLDL(-) but not in nagLDL(-) or LDL(+). Choline-containing phospholipids were extensively degraded, and ceramide, diacylglycerol, monoacylglycerol, and phosphorylcholine were the main products generated, suggesting the involvement of phospholipase C-like activity. The properties of agLDL(-) suggest that this subfraction plays a major role in atherogenesis by triggering lipoprotein fusion and cholesterol accumulation in the arterial wall.
Collapse
Affiliation(s)
- Cristina Bancells
- Departament de Bioquímica, Institut d'Investigacions Biomèdiques Sant Pau, Hospital de la Santa Creu i Sant Pau, 08025 Barcelona, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Bancells C, Sánchez-Quesada JL, Birkelund R, Ordóñez-Llanos J, Benítez S. HDL and electronegative LDL exchange anti- and pro-inflammatory properties. J Lipid Res 2010; 51:2947-56. [PMID: 20647593 DOI: 10.1194/jlr.m005777] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Electronegative LDL [LDL(-)] is a minor modified LDL subfraction present in blood with inflammatory effects. One of the antiatherogenic properties of HDL is the inhibition of the deleterious effects of in vitro modified LDL. However, the effect of HDL on the inflammatory activity of LDL(-) isolated from plasma is unknown. We aimed to assess the putative protective role of HDL against the cytokine released induced in monocytes by LDL(-). Our results showed that LDL(-) cytokine release was inhibited when LDL(-) was coincubated with HDL and human monocytes and also when LDL(-) was preincubated with HDL and reisolated prior to cell incubation. The addition of apoliprotein (apo)AI instead of HDL reproduced the protective behavior of HDL. HDL preincubated with LDL(-) promoted greater cytokine release than native HDL. Incubation of LDL(-) with HDL decreased the electronegative charge, phospholipase C-like activity, susceptibility to aggregation and nonesterified fatty acid (NEFA) content of LDL(-), whereas these properties increased in HDL. NEFA content in LDL appeared to be related to cytokine production because NEFA-enriched LDL induced cytokine release. HDL, at least in part through apoAI, inhibits phospholipase-C activity and cytokine release in monocytes, thereby counteracting the inflammatory effect of LDL(-). In turn, HDL acquires these properties and becomes inflammatory.
Collapse
Affiliation(s)
- Cristina Bancells
- Institut de Recerca, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | | | | | | | | |
Collapse
|
30
|
Diabetes in relation to biliary tract cancer and stones: a population-based study in Shanghai, China. Br J Cancer 2010; 103:115-9. [PMID: 20517308 PMCID: PMC2905288 DOI: 10.1038/sj.bjc.6605706] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Biliary tract cancers are rare but fatal malignancies. Diabetes has been related to biliary stones, but its association with biliary tract cancers is less conclusive. METHODS In a population-based case-control study of 627 cancers, 1037 stones, and 959 controls in Shanghai, China, we examined the association between diabetes and the risks of biliary tract cancer and stones, as well as the effect of potential mediating factors, including serum lipids and biliary stones (for cancer), contributing to the causal pathway from diabetes to biliary diseases. RESULTS Independent of body mass index (BMI), diabetes was significantly associated with gallbladder cancer and biliary stones ((odds ratio (OR) (95% confidence interval)=2.6 (1.5-4.7) and 2.0 (1.2-3.3), respectively). Biliary stones and low serum levels of high-density lipoprotein (HDL) were significant mediators of the diabetes effect on gallbladder cancer risk, accounting for 60 and 17% of the diabetes effect, respectively. High-density lipoprotein was also a significant mediator of the diabetes effect on biliary stones, accounting for 18% of the diabetes effect. CONCLUSIONS Independent of BMI, diabetes is a risk factor for gallbladder cancer, but its effect is mediated in part by biliary stones and serum HDL levels, suggesting that gallbladder cancer risk may be reduced by controlling diabetes, stones, and HDL levels.
Collapse
|
31
|
Santo Faulin TDE, de Sena KCM, Rodrigues Telles AE, de Mattos Grosso D, Bernardi Faulin EJ, Parra Abdalla DS. Validation of a novel ELISA for measurement of electronegative low-density lipoprotein. Clin Chem Lab Med 2009; 46:1769-75. [PMID: 19055454 DOI: 10.1515/cclm.2008.333] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Oxidative modification of low-density lipoprotein (LDL) plays a key role in the pathogenesis of atherosclerosis. LDL(-) is present in blood plasma of healthy subjects and at higher concentrations in diseases with high cardiovascular risk, such as familial hypercholesterolemia or diabetes. METHODS We developed and validated a sandwich ELISA for LDL(-) in human plasma using two monoclonal antibodies against LDL(-) that do not bind to native LDL, extensively copper-oxidized LDL or malondialdehyde-modified LDL. The characteristics of assay performance, such as limits of detection and quantification, accuracy, inter- and intra-assay precision were evaluated. The linearity, interferences and stability tests were also performed. RESULTS The calibration range of the assay is 0.625-20.0 mU/L at 1:2000 sample dilution. ELISA validation showed intra- and inter-assay precision and recovery within the required limits for immunoassays. The limits of detection and quantification were 0.423 mU/L and 0.517 mU/L LDL(-), respectively. The intra- and inter-assay coefficient of variation ranged from 9.5% to 11.5% and from 11.3% to 18.9%, respectively. Recovery of LDL(-) ranged from 92.8% to 105.1%. CONCLUSIONS This ELISA represents a very practical tool for measuring LDL(-) in human blood for widespread research and clinical sample use.
Collapse
|
32
|
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.
Collapse
Affiliation(s)
- Denise Mafra
- Department of Clinical Nutrition, Federal Fluminense University (UFF), Niterói, Brazil.
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Lu J, Yang JH, Burns AR, Chen HH, Tang D, Walterscheid JP, Suzuki S, Yang CY, Sawamura T, Chen CH. Mediation of electronegative low-density lipoprotein signaling by LOX-1: a possible mechanism of endothelial apoptosis. Circ Res 2009; 104:619-27. [PMID: 19150883 DOI: 10.1161/circresaha.108.190116] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The lectin-like oxidized LDL receptor LOX-1 mediates endothelial cell (EC) uptake of experimentally prepared copper-oxidized LDL (oxLDL). To confirm the atherogenic role of this receptor cloned against copper-oxLDL, we examined whether it mediates EC uptake of L5, an electronegative LDL abundant in dyslipidemic but not normolipidemic human plasma. Hypercholesterolemic (LDL-cholesterol, >160 mg/dL) human LDL was fractionated into L1-L5, increasingly electronegative, by ion-exchange chromatography. In cultured bovine aortic ECs (BAECs), L5 upregulated LOX-1 and induced apoptosis. Transfection of BAECs with LOX-1-specific small interfering RNAs (siLOX-1) minimized baseline LOX-1 production and restrained L5-induced LOX-1 upregulation. Internalization of labeled L1-L5 was monitored in BAECs and human umbilical venous ECs by fluorescence microscopy. LOX-1 knockdown with siLOX-1 impeded the endocytosis of L5 but not L1-L4. In contrast, blocking LDL receptor with RAP (LDL receptor-associated protein) stopped the internalization of L1-L4 but not L5. Although chemically different, L5 and oxLDL competed for EC entry through LOX-1. Via LOX-1, L5 signaling hampered Akt phosphorylation and suppressed EC expression of fibroblast growth factor-2 and Bcl-2. L5 also selectively inhibited Bcl-xL expression and endothelial nitric oxide synthase phosphorylation but increased synthesis of Bax, Bad, and tumor necrosis factor-alpha. Blocking Akt phosphorylation with wortmannin increased LOX-1 expression, suggesting a modulatory role of Akt in LOX-1 synthesis; L5 upregulated LOX-1 by dephosphorylating Akt. Because endothelial nitric oxide synthase and Bcl-2 activities are Akt-dependent, L5 impairs Akt-mediated growth and survival signals in vascular ECs by way of LOX-1. Thus, the L5/LOX-1 complex may play a critical role in atherogenesis and illuminate important targets for disease intervention.
Collapse
Affiliation(s)
- Jonathan Lu
- Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Zhang B, Matsunaga A, Rainwater DL, Miura SI, Noda K, Nishikawa H, Uehara Y, Shirai K, Ogawa M, Saku K. Effects of rosuvastatin on electronegative LDL as characterized by capillary isotachophoresis: the ROSARY Study. J Lipid Res 2008; 50:1832-41. [PMID: 19056704 DOI: 10.1194/jlr.m800523-jlr200] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Electronegative LDL, a charge-modified LDL (cm-LDL) subfraction that is more negatively charged than normal LDL, has been shown to be inflammatory. We previously showed that pravastatin and simvastatin reduced the electronegative LDL subfraction, fast-migrating LDL (fLDL), as analyzed by capillary isotachophoresis (cITP). The present study examined the effects of rosuvastatin on the more electronegative LDL subfraction, very-fast-migrating LDL (vfLDL), and small, dense charge-modified LDL (sd-cm-LDL) subfractions. Patients with hypercholesterolemia or those who were being treated with statins (n = 81) were treated with or switched to 2.5 mg/d rosuvastatin for 3 months. Rosuvastatin treatment effectively reduced cITP cm-LDL subfractions of LDL (vfLDL and fLDL) or sdLDL (sd-vfLDL and sd-fLDL), which were closely related to each other but were different from the normal subfraction of LDL [slow-migrating LDL (sLDL)] or sdLDL (sd-sLDL) in their relation to the levels of remnant-like particle cholesterol (RLP-C), apolipoprotein (apo) C-II, and apoE. The percent changes in cm-LDL or sd-cm-LDL caused by rosuvastatin were correlated with those in the particle concentrations of LDL or sdLDL measured as LDL-apoB or sdLDL-apoB and the levels of HDL-C, RLP-C, apoC-II, and apoE. In conclusion, rosuvastatin effectively reduced both the vfLDL subfraction and sd-cm-LDL subfractions as analyzed by cITP.
Collapse
Affiliation(s)
- Bo Zhang
- Department of Cardiology, Fukuoka University School of Medicine, Fukuoka 814-0180, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
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.
Collapse
Affiliation(s)
- Cristina Bancells
- Servei de Bioquímica, Institut de Recerca, Hospital de la Santa Creu i Sant Pau
| | | | | | | | | | | |
Collapse
|
36
|
Andreotti G, Chen J, Gao YT, Rashid A, Chang SC, Shen MC, Wang BS, Han TQ, Zhang BH, Danforth KN, Althuis MD, Hsing AW. Serum lipid levels and the risk of biliary tract cancers and biliary stones: A population-based study in China. Int J Cancer 2008; 122:2322-9. [PMID: 18076041 DOI: 10.1002/ijc.23307] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Biliary tract cancers, encompassing the gallbladder, extrahepatic bile ducts and ampulla of Vater, are rare but highly fatal malignancies. Gallstones, the predominant risk factor for biliary cancers, are linked with hyperlipidemia. As part of a population-based case-control study conducted in Shanghai, China, we examined the associations of serum lipid levels with biliary stones and cancers. We included 460 biliary cancer cases (264 gallbladder, 141 extrahepatic bile duct, and 55 ampulla of Vater), 981 biliary stone cases and 858 healthy individuals randomly selected from the population. Participants completed an in-person interview and gave overnight fasting blood samples. Participants in the highest quintile of triglycerides (>/=160 mg/dl) had a 1.4-fold risk of biliary stones (95% CI = 1.1-1.9), a 1.9-fold risk of gallbladder cancer (95% CI = 1.3-2.8), and a 4.8-fold risk of bile duct cancer (95% CI = 2.8-8.1), compared to the reference group (third quintile: 90-124 mg/dl). Participants in the lowest quintile of high-density lipoprotein (HDL) (<30 mg/dl) had a 4.2-fold risk of biliary stones (95% CI = 3.0-6.0), an 11.6-fold risk of gallbladder cancer (95% CI = 7.3-18.5), and a 16.8-fold risk of bile duct cancer (95% CI = 9.1-30.9), relative to the reference group (third quintile: 40-49 mg/dl). In addition, total cholesterol, low-density lipoprotein (LDL) and apolipoprotein A (apo A) were inversely associated with biliary stones; whereas low levels as well as high levels of total cholesterol, LDL, apo A and apolipoprotein B (apo B) were associated with excess risks of biliary tract cancers. Our findings support a role for serum lipids in gallstone development and biliary carcinogenesis.
Collapse
Affiliation(s)
- Gabriella Andreotti
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, DHHS, Bethesda, MD, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Zhang B, Miura SI, Yanagi D, Noda K, Nishikawa H, Matsunaga A, Shirai K, Iwata A, Yoshinaga K, Adachi H, Imaizumi T, Saku K. Reduction of charge-modified LDL by statin therapy in patients with CHD or CHD risk factors and elevated LDL-C levels: the SPECIAL Study. Atherosclerosis 2008; 201:353-9. [PMID: 18395728 DOI: 10.1016/j.atherosclerosis.2008.02.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2007] [Revised: 02/04/2008] [Accepted: 02/10/2008] [Indexed: 10/22/2022]
Abstract
Various forms of atherogenic modified low-density lipoprotein (LDL) including oxidized LDL and small, dense LDL have increased negative charge as compared to normal LDL. Charge-modified LDL (electronegative LDL) and normal LDL subfractions in plasma are analyzed by capillary isotachophoresis (cITP) as fast-migrating LDL (fLDL) and slow-migrating LDL (sLDL). We examined the effects of pravastatin and simvastatin on charge-based LDL subfractions as determined by cITP in patients with hypercholesterolemia. Patients (n=72) with CHD or CHD risk factors and elevated LDL cholesterol (LDL-C) levels were randomly assigned to receive pravastatin or simvastatin. After treatment with statins for 3 and 6 months, both cITP fLDL and sLDL were reduced (p<0.05) from the baseline, but the effects did not differ between treatment with pravastatin and simvastatin. At baseline and after treatment for 3 months, cITP sLDL was correlated with LDL-C, but fLDL was correlated with inflammatory markers, high-sensitive C-reactive protein and LDL-associated platelet-activating factor acetylhydrolase, and atherogenic lipoproteins, remnant-like particle cholesterol and small, dense LDL cholesterol. In conclusion, cITP fLDL was related to inflammatory markers and atherogenic lipoproteins and was reduced by treatment with statins. Charge-modified LDL subfraction could be a potential marker for atherosclerosis and a target for therapy.
Collapse
Affiliation(s)
- Bo Zhang
- Department of Cardiology, Fukuoka University School of Medicine, Fukuoka, Japan.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Andreotti G, Chen J, Gao YT, Rashid A, Chen BE, Rosenberg P, Sakoda LC, Deng J, Shen MC, Wang BS, Han TQ, Zhang BH, Yeager M, Welch R, Chanock S, Fraumeni JF, Hsing AW. Polymorphisms of genes in the lipid metabolism pathway and risk of biliary tract cancers and stones: a population-based case-control study in Shanghai, China. Cancer Epidemiol Biomarkers Prev 2008; 17:525-34. [PMID: 18296645 DOI: 10.1158/1055-9965.epi-07-2704] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Biliary tract cancers, encompassing the gallbladder, extrahepatic bile duct, and ampulla of Vater, are uncommon yet highly fatal malignancies. Gallstones, the primary risk factor for biliary cancers, are linked with hyperlipidemia. We examined the associations of 12 single nucleotide polymorphisms of five genes in the lipid metabolism pathway with the risks of biliary cancers and stones in a population-based case-control study in Shanghai, China. We included 235 gallbladder, 125 extrahepatic bile duct, and 46 ampulla of Vater cancer cases, 880 biliary stone cases, and 779 population controls. Subjects completed an in-person interview and gave blood. Genotyping was conducted by TaqMan assay using DNA from buffy coats. The effects of APOE IVS1+69 (rs440446) and APOB IVS6+360C>T (rs520354) markers were limited to men. Men carrying the G allele of APOE IVS1+69 had a 1.7-fold risk of stones [95% confidence interval (95% CI), 1.2-2.4], a 1.8-fold risk of gallbladder cancer (95% CI, 1.0-3.3), a 3.7-fold risk of bile duct cancer (95% CI, 2.0-7.0), and a 4-fold risk of ampullary cancer (95% CI, 1.4-12.4). Male carriers of the T allele of APOB IVS6+360C>T had a 2-fold risk of bile duct cancer (95% CI, 1.2-3.4). The APOB T-T haplotype (APOB IVS6+360C>T, EX4+56C>T) was associated with a 1.6-fold risk of bile duct cancer (95% CI, 1.1-2.3). Male and female carriers of the T allele of LDLR IVS9-30C>T (rs1003723) had a 1.5-fold risk of bile duct cancer. Our findings suggest that gene variants in the lipid metabolism pathway contribute to the risk of biliary tract stones and cancers, particularly of the bile duct.
Collapse
Affiliation(s)
- Gabriella Andreotti
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Department of Health and Human Services, 6120 Executive Boulevard, EPS 8011, MSC 7240, Bethesda, MD 20892, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Drissner D, Kunze G, Callewaert N, Gehrig P, Tamasloukht M, Boller T, Felix G, Amrhein N, Bucher M. Lyso-phosphatidylcholine is a signal in the arbuscular mycorrhizal symbiosis. Science 2007; 318:265-8. [PMID: 17932296 DOI: 10.1126/science.1146487] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The arbuscular mycorrhizal (AM) symbiosis represents the most widely distributed mutualistic root symbiosis. We report that root extracts of mycorrhizal plants contain a lipophilic signal capable of inducing the phosphate transporter genes StPT3 and StPT4 of potato (Solanum tuberosum L.), genes that are specifically induced in roots colonized by AM fungi. The same signal caused rapid extracellular alkalinization in suspension-cultured tomato (Solanum lycopersicum L.) cells and induction of the mycorrhiza-specific phosphate transporter gene LePT4 in these cells. The active principle was characterized as the lysolipid lyso-phosphatidylcholine (LPC) via a combination of gene expression studies, alkalinization assays in cell cultures, and chromatographic and mass spectrometric analyses. Our results highlight the importance of lysophospholipids as signals in plants and in particular in the AM symbiosis.
Collapse
Affiliation(s)
- David Drissner
- Institute of Plant Sciences, Eidgenössische Technische Hochschule (ETH) Zurich, Experimental Station Eschikon 33, 8315 Lindau, Switzerland
| | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Benítez S, Bancells C, Ordóñez-Llanos J, Sánchez-Quesada JL. Pro-inflammatory action of LDL(−) on mononuclear cells is counteracted by increased IL10 production. Biochim Biophys Acta Mol Cell Biol Lipids 2007; 1771:613-22. [PMID: 17442617 DOI: 10.1016/j.bbalip.2007.03.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2006] [Revised: 03/01/2007] [Accepted: 03/02/2007] [Indexed: 10/23/2022]
Abstract
OBJECTIVE LDL(-) is a minor LDL subfraction that induces inflammatory factor release by endothelial cells. Since LDL(-) is present in plasma, its interaction with leucocytes, a cell type involved in atherosclerosis phenomena, is feasible; therefore, the aim of the current study was to evaluate LDL(-) effect on lymphocytes and monocytes isolated from human plasma. METHODS AND RESULTS Mononuclear cells were incubated with LDL(+) and LDL(-) and expression and release of several inflammatory mediators were analyzed by protein membrane assay, ELISA and real-time RT-PCR. LDL(-) induced a significantly increased production versus LDL(+) in MCP1, GRObeta, GROgamma, IL6, IL8 and IL10 in monocytes as well as in lymphocytes. These induced molecules are inflammatory, except for IL10 which is considered an anti-inflammatory cytokine. Therefore, the role of IL10 was evaluated in experiments where exogenous IL10 or antibodies anti-IL10 or anti-IL10 receptor were added. IL10 addition diminished the release of the other factors induced by LDL(-) near to basal production both at protein and RNA level. In contrast, the antibody anti-IL10 increased inflammatory cytokine release around two-fold, whereas the antibody anti-IL10 receptor produced a lower effect. CONCLUSIONS LDL(-) promoted inflammatory cytokine production in leucocytes; however, it also induced IL10 that minimized this effect. Therefore, IL10 developed a significant role in counteracting the LDL(-) inflammatory action.
Collapse
Affiliation(s)
- Sònia Benítez
- Servei Bioquímica, Institut de Recerca, Hospital de la Santa Creu i Sant Pau, C/Antoni Maria Claret 167, 08025 Barcelona, Spain.
| | | | | | | |
Collapse
|
41
|
de Castellarnau C, Bancells C, Benítez S, Reina M, Ordóñez-Llanos J, Sánchez-Quesada JL. Atherogenic and inflammatory profile of human arterial endothelial cells (HUAEC) in response to LDL subfractions. Clin Chim Acta 2007; 376:233-6. [PMID: 16956600 DOI: 10.1016/j.cca.2006.07.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2006] [Revised: 07/25/2006] [Accepted: 07/25/2006] [Indexed: 11/17/2022]
Abstract
BACKGROUND Electronegative LDL (LDL(-)) is a minor modified LDL fraction present in plasma that has been demonstrated to be inflammatory in endothelial cells isolated from human umbilical vein (HUVEC). METHODS A protein array able to measure 42 cytokines, chemokines and related compounds involved in atherogenesis was used to determine their release into the culture medium of human arterial endothelial cells (HUAEC) activated or not by two low-density lipoprotein (LDL) fractions isolated from human plasma by anion-exchange chromatography. RESULTS The results of the protein array (confirmed using specific ELISAs for each induced factor) revealed that HUAEC in the absence of stimuli released small amounts of interleukin 8 (IL-8), monocyte chemotactic protein 1 (MCP-1) and growth-related oncogene (GRO). The major native LDL fraction (named LDL(+)) increased the release of these molecules and also those of interleukin 6 (IL-6) and GROalpha. Compared to LDL(+), the minor modified fraction, named electronegative LDL (LDL(-)), increased all these factors to a greater degree and also induced the release of granulocyte-monocyte colony-stimulating factor (GM-CSF) and platelet-derived growth factor B (PDGF-B). These results were confirmed by ELISA. CONCLUSIONS All these results indicate that, compared to LDL(+), LDL(-) fraction promotes not only the release of proinflammatory factors but also those of atherogenic factors in endothelial cells of arterial origin, thereby suggesting a new role for LDL(-) in atherogenesis.
Collapse
Affiliation(s)
- Conxita de Castellarnau
- Department of Cell Biology, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; Advancell S.L. Barcelona Science Park, Barcelona, Spain
| | | | | | | | | | | |
Collapse
|