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Ramasamy R, Shekhtman A, Schmidt AM. RAGE/DIAPH1 and atherosclerosis through an evolving lens: Viewing the cell from the "Inside - Out". Atherosclerosis 2024; 394:117304. [PMID: 39131441 PMCID: PMC11309734 DOI: 10.1016/j.atherosclerosis.2023.117304] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
Background and aims In hyperglycemia, inflammation, oxidative stress and aging, Damage Associated Molecular Patterns (DAMPs) accumulate in conditions such as atherosclerosis. Binding of DAMPs to receptors such as the receptor for advanced glycation end products (RAGE) activates signal transduction cascades that contribute to cellular stress. The cytoplasmic domain (tail) of RAGE (ctRAGE) binds to the formin Diaphanous1 (DIAPH1), which is important for RAGE signaling. This Review will detail the evidence linking the RAGE/DIAPH1 signaling pathway to atherosclerosis and envisages future therapeutic opportunities from the "inside-out" point of view in affected cells. Methods PubMed was searched using a variety of search terms, including "receptor for advanced glycation end products" along with various combinations including "and atherosclerosis," "soluble RAGE and atherosclerosis," "statins and RAGE," "PPAR and RAGE" and "SGLT2 inhibitor and RAGE." Results In non-diabetic and diabetic mice, antagonism or global deletion of Ager (the gene encoding RAGE) retards progression and accelerates regression of atherosclerosis. Global deletion of Diaph1 in mice devoid of the low density lipoprotein receptor (Ldlr) significantly attenuates atherosclerosis; mice devoid of both Diaph1 and Ldlr display significantly lower plasma and liver concentrations of cholesterol and triglyceride compared to mice devoid of Ldlr. Associations between RAGE pathway and human atherosclerosis have been identified based on relationships between plasma/serum concentrations of RAGE ligands, soluble RAGEs and atherosclerosis. Conclusions Efforts to target RAGE/DIAPH1 signaling through a small molecule antagonist therapeutic strategy hold promise to quell accelerated atherosclerosis in diabetes and in other forms of cardiovascular disease.
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Affiliation(s)
- Ravichandran Ramasamy
- Diabetes Research Program, Department of Medicine, New York University Grossman School of Medicine, NYU Langone Medical Center, NY, USA
| | - Alexander Shekhtman
- Department of Chemistry, The State University of New York at Albany, Albany, NY, USA
| | - Ann Marie Schmidt
- Diabetes Research Program, Department of Medicine, New York University Grossman School of Medicine, NYU Langone Medical Center, NY, USA
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Arivazhagan L, López-Díez R, Shekhtman A, Ramasamy R, Schmidt AM. Glycation and a Spark of ALEs (Advanced Lipoxidation End Products) - Igniting RAGE/Diaphanous-1 and Cardiometabolic Disease. Front Cardiovasc Med 2022; 9:937071. [PMID: 35811725 PMCID: PMC9263181 DOI: 10.3389/fcvm.2022.937071] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 05/30/2022] [Indexed: 12/25/2022] Open
Abstract
Obesity and non-alcoholic fatty liver disease (NAFLD) are on the rise world-wide; despite fervent advocacy for healthier diets and enhanced physical activity, these disorders persist unabated and, long-term, are major causes of morbidity and mortality. Numerous fundamental biochemical and molecular pathways participate in these events at incipient, mid- and advanced stages during atherogenesis and impaired regression of established atherosclerosis. It is proposed that upon the consumption of high fat/high sugar diets, the production of receptor for advanced glycation end products (RAGE) ligands, advanced glycation end products (AGEs) and advanced lipoxidation end products (ALEs), contribute to the development of foam cells, endothelial injury, vascular inflammation, and, ultimately, atherosclerosis and its consequences. RAGE/Diaphanous-1 (DIAPH1) increases macrophage foam cell formation; decreases cholesterol efflux and causes foam cells to produce and release damage associated molecular patterns (DAMPs) molecules, which are also ligands of RAGE. DAMPs stimulate upregulation of Interferon Regulatory Factor 7 (IRF7) in macrophages, which exacerbates vascular inflammation and further perturbs cholesterol metabolism. Obesity and NAFLD, characterized by the upregulation of AGEs, ALEs and DAMPs in the target tissues, contribute to insulin resistance, hyperglycemia and type two diabetes. Once in motion, a vicious cycle of RAGE ligand production and exacerbation of RAGE/DIAPH1 signaling ensues, which, if left unchecked, augments cardiometabolic disease and its consequences. This Review focuses on RAGE/DIAPH1 and its role in perturbation of metabolism and processes that converge to augur cardiovascular disease.
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Affiliation(s)
- Lakshmi Arivazhagan
- Diabetes Research Program, Department of Medicine, New York University Grossman School of Medicine, New York, NY, United States
| | - Raquel López-Díez
- Diabetes Research Program, Department of Medicine, New York University Grossman School of Medicine, New York, NY, United States
| | - Alexander Shekhtman
- Department of Chemistry, The State University of New York at Albany, Albany, NY, United States
| | - Ravichandran Ramasamy
- Diabetes Research Program, Department of Medicine, New York University Grossman School of Medicine, New York, NY, United States
| | - Ann Marie Schmidt
- Diabetes Research Program, Department of Medicine, New York University Grossman School of Medicine, New York, NY, United States,*Correspondence: Ann Marie Schmidt
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Mocanu CA, Fuior EV, Voicu G, Rebleanu D, Safciuc F, Deleanu M, Fenyo IM, Escriou V, Manduteanu I, Simionescu M, Calin M. P-selectin targeted RAGE-shRNA lipoplexes alleviate atherosclerosis-associated inflammation. J Control Release 2021; 338:754-772. [PMID: 34530051 DOI: 10.1016/j.jconrel.2021.09.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 09/03/2021] [Accepted: 09/10/2021] [Indexed: 12/19/2022]
Abstract
The receptor for advanced glycation end products (RAGE) plays a central role in the chronic inflammatory process associated with atherosclerosis development. We aimed to develop lipoplexes carrying RAGE-short hairpin (sh) RNA, targeted to the adhesion molecule P-selectin, selectively expressed on the surface of activated endothelium (Psel-lipo/shRAGE) to down-regulate RAGE expression as a therapeutic strategy for atherosclerosis. In vitro, Psel-lipo/shRAGE lipoplexes were efficiently taken up by activated endothelial cells (EC), decreased the expression of RAGE protein, and proved to be functional by reducing the monocyte adhesion to activated EC. In ApoE-deficient mice, the targeted lipoplexes accumulated specifically and efficiently transfected the aorta. The repeated administration of Psel-lipo/shRAGE lipoplexes, twice per week for one month: i) reduced the expression of RAGE protein in the aorta by decreasing the expression of NF-kB and TNF-α; ii) diminished the plasma levels of TNF-α, IL6, IL-1β, and MCP-1; iii) inhibited the atherosclerotic plaque development and iv) had no significant adverse effects. In conclusion, the newly developed Psel-lipo/shRAGE lipoplexes reduce the inflammatory processes associated with RAGE signaling and the progression of atherosclerosis in ApoE-deficient mice. Downregulation of RAGE employing these lipoplexes may represent a promising new targeted therapy to block atherosclerosis progression.
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Affiliation(s)
- Cristina Ana Mocanu
- "Medical and Pharmaceutical Bionanotechnologies" Laboratory, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 050568 Bucharest, Romania
| | - Elena Valeria Fuior
- "Medical and Pharmaceutical Bionanotechnologies" Laboratory, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 050568 Bucharest, Romania
| | - Geanina Voicu
- "Medical and Pharmaceutical Bionanotechnologies" Laboratory, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 050568 Bucharest, Romania
| | - Daniela Rebleanu
- "Medical and Pharmaceutical Bionanotechnologies" Laboratory, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 050568 Bucharest, Romania
| | - Florentina Safciuc
- "Medical and Pharmaceutical Bionanotechnologies" Laboratory, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 050568 Bucharest, Romania
| | - Mariana Deleanu
- "Liquid and Gas Chromatography" Laboratory, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 050568 Bucharest, Romania
| | - Ioana Madalina Fenyo
- "Gene Regulation and Molecular Therapies" Laboratory, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 050568 Bucharest, Romania
| | | | - Ileana Manduteanu
- "Medical and Pharmaceutical Bionanotechnologies" Laboratory, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 050568 Bucharest, Romania
| | - Maya Simionescu
- "Medical and Pharmaceutical Bionanotechnologies" Laboratory, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 050568 Bucharest, Romania
| | - Manuela Calin
- "Medical and Pharmaceutical Bionanotechnologies" Laboratory, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 050568 Bucharest, Romania.
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Prantner D, Nallar S, Vogel SN. The role of RAGE in host pathology and crosstalk between RAGE and TLR4 in innate immune signal transduction pathways. FASEB J 2020; 34:15659-15674. [PMID: 33131091 DOI: 10.1096/fj.202002136r] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/07/2020] [Accepted: 10/13/2020] [Indexed: 12/15/2022]
Abstract
Although the innate immune receptor protein, Receptor for Advanced Glycation End products (RAGE), has been extensively studied, there has been renewed interest in RAGE for its potential role in sepsis, along with a host of other inflammatory diseases of chronic, noninfectious origin. In contrast to other innate immune receptors, for example, Toll-like receptors (TLRs), that recognize ligands derived from pathogenic organisms that are collectively known as "pathogen-associated molecular patterns" (PAMPs) or host-derived "damage-associated molecular patterns" (DAMPs), RAGE has been shown to recognize a broad collection of DAMPs exclusively. Historically, these DAMPs have been shown to be pro-inflammatory in nature. Early studies indicated that the adaptor molecule, MyD88, might be important for this change. More recent studies have explored further the mechanisms underlying this inflammatory change. Overall, the newer results have shown that there is extensive crosstalk between RAGE and TLRs. The three canonical RAGE ligands, Advanced Glycation End products (AGEs), HMGB1, and S100 proteins, have all been shown to activate both TLRs and RAGE to varying degrees in order to induce inflammation in in vitro models. As with any field that delves deeply into innate signaling, obstacles of reagent purity may be a cause of some of the discrepancies in the literature, and we have found that commercial antibodies that have been widely used exhibit a high degree of nonspecificity. Nonetheless, the weight of published evidence has led us to speculate that RAGE may be physically interacting with TLRs on the cell surface to elicit inflammation via MyD88-dependent signaling.
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Affiliation(s)
- Daniel Prantner
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Shreeram Nallar
- Institute of Human Virology, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Stefanie N Vogel
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD, USA
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Zhang W, Zhang Y, Ding K, Zhang H, Zhao Q, Liu Z, Xu Y. Involvement of JNK1/2-NF-κBp65 in the regulation of HMGB2 in myocardial ischemia/reperfusion-induced apoptosis in human AC16 cardiomyocytes. Biomed Pharmacother 2018; 106:1063-1071. [DOI: 10.1016/j.biopha.2018.07.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 06/29/2018] [Accepted: 07/01/2018] [Indexed: 12/20/2022] Open
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Schmidt AM. 22016 ATVB Plenary Lecture: Receptor for Advanced Glycation Endproducts and Implications for the Pathogenesis and Treatment of Cardiometabolic Disorders: Spotlight on the Macrophage. Arterioscler Thromb Vasc Biol 2017; 37:613-621. [PMID: 28183700 DOI: 10.1161/atvbaha.117.307263] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 01/30/2017] [Indexed: 12/23/2022]
Abstract
The receptor for advanced glycation endproducts (RAGE) interacts with a unique repertoire of ligands that form and collect in the tissues and circulation in diabetes mellitus, aging, inflammation, renal failure, and obesity. RAGE is expressed on multiple cell types linked to tissue perturbation in these settings. This brief review focuses on the role of RAGE in monocytes/macrophages and how RAGE ligand engagement on these cells mediates seminal changes in monocyte/macrophage migration, oxidative stress, cholesterol efflux, and pro- versus anti-inflammatory cues that signal to tissue damage. Studies using mice devoid of Ager (gene encoding RAGE) or pharmacological antagonists of RAGE are protective in animal models of diabetes mellitus, atherosclerosis, and high-fat diet-induced obesity, in least in part through key roles in monocytes/macrophages. RAGE signal transduction requires the interaction of RAGE cytoplasmic domain with the formin, DIAPH1 (diaphanous 1) and novel antagonists of this interaction show significant promise in attenuation of the maladaptive effects of RAGE ligands in cellular and in vivo models. Finally, this brief review discusses evidence for RAGE axis perturbation in human monocytes/macrophages and how tracing RAGE activity in these cells may identify target engagement biomarkers of RAGE antagonism for future clinical trials.
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Affiliation(s)
- Ann Marie Schmidt
- From the Diabetes Research Program, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University School of Medicine, New York.
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Daffu G, Shen X, Senatus L, Thiagarajan D, Abedini A, Hurtado Del Pozo C, Rosario R, Song F, Friedman RA, Ramasamy R, Schmidt AM. RAGE Suppresses ABCG1-Mediated Macrophage Cholesterol Efflux in Diabetes. Diabetes 2015; 64:4046-60. [PMID: 26253613 PMCID: PMC4657581 DOI: 10.2337/db15-0575] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 07/23/2015] [Indexed: 01/13/2023]
Abstract
Diabetes exacerbates cardiovascular disease, at least in part through suppression of macrophage cholesterol efflux and levels of the cholesterol transporters ATP binding cassette transporter A1 (ABCA1) and ABCG1. The receptor for advanced glycation end products (RAGE) is highly expressed in human and murine diabetic atherosclerotic plaques, particularly in macrophages. We tested the hypothesis that RAGE suppresses macrophage cholesterol efflux and probed the mechanisms by which RAGE downregulates ABCA1 and ABCG1. Macrophage cholesterol efflux to apolipoprotein A1 and HDL and reverse cholesterol transport to plasma, liver, and feces were reduced in diabetic macrophages through RAGE. In vitro, RAGE ligands suppressed ABCG1 and ABCA1 promoter luciferase activity and transcription of ABCG1 and ABCA1 through peroxisome proliferator-activated receptor-γ (PPARG)-responsive promoter elements but not through liver X receptor elements. Plasma levels of HDL were reduced in diabetic mice in a RAGE-dependent manner. Laser capture microdissected CD68(+) macrophages from atherosclerotic plaques of Ldlr(-/-) mice devoid of Ager (RAGE) displayed higher levels of Abca1, Abcg1, and Pparg mRNA transcripts versus Ager-expressing Ldlr(-/-) mice independently of glycemia or plasma levels of total cholesterol and triglycerides. Antagonism of RAGE may fill an important therapeutic gap in the treatment of diabetic macrovascular complications.
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MESH Headings
- ATP Binding Cassette Transporter 1/genetics
- ATP Binding Cassette Transporter 1/metabolism
- ATP Binding Cassette Transporter, Subfamily G, Member 1
- ATP-Binding Cassette Transporters/antagonists & inhibitors
- ATP-Binding Cassette Transporters/genetics
- ATP-Binding Cassette Transporters/metabolism
- Animals
- Aorta/immunology
- Aorta/metabolism
- Aorta/pathology
- Biological Transport
- Cell Line
- Cells, Cultured
- Cholesterol/metabolism
- Diabetic Angiopathies/blood
- Diabetic Angiopathies/immunology
- Diabetic Angiopathies/metabolism
- Diabetic Angiopathies/pathology
- Glycation End Products, Advanced/blood
- Glycation End Products, Advanced/metabolism
- Humans
- Ligands
- Lipoproteins/antagonists & inhibitors
- Lipoproteins/genetics
- Lipoproteins/metabolism
- Macrophages/cytology
- Macrophages/immunology
- Macrophages/metabolism
- Macrophages/pathology
- Male
- Mice, Knockout
- PPAR gamma/genetics
- PPAR gamma/metabolism
- Plaque, Atherosclerotic/blood
- Plaque, Atherosclerotic/immunology
- Plaque, Atherosclerotic/metabolism
- Plaque, Atherosclerotic/pathology
- Promoter Regions, Genetic
- Receptor for Advanced Glycation End Products/agonists
- Receptor for Advanced Glycation End Products/blood
- Receptor for Advanced Glycation End Products/genetics
- Receptor for Advanced Glycation End Products/metabolism
- Recombinant Proteins/chemistry
- Recombinant Proteins/metabolism
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Affiliation(s)
- Gurdip Daffu
- Diabetes Research Program, Division of Endocrinology, Department of Medicine, New York University School of Medicine, New York, NY
| | - Xiaoping Shen
- Diabetes Research Program, Division of Endocrinology, Department of Medicine, New York University School of Medicine, New York, NY
| | - Laura Senatus
- Diabetes Research Program, Division of Endocrinology, Department of Medicine, New York University School of Medicine, New York, NY
| | - Devi Thiagarajan
- Diabetes Research Program, Division of Endocrinology, Department of Medicine, New York University School of Medicine, New York, NY
| | - Andisheh Abedini
- Diabetes Research Program, Division of Endocrinology, Department of Medicine, New York University School of Medicine, New York, NY
| | - Carmen Hurtado Del Pozo
- Diabetes Research Program, Division of Endocrinology, Department of Medicine, New York University School of Medicine, New York, NY
| | - Rosa Rosario
- Diabetes Research Program, Division of Endocrinology, Department of Medicine, New York University School of Medicine, New York, NY
| | - Fei Song
- Diabetes Research Program, Division of Endocrinology, Department of Medicine, New York University School of Medicine, New York, NY
| | - Richard A Friedman
- Biomedical Informatics Shared Resource, Herbert Irving Comprehensive Cancer Center, and Department of Biomedical Informatics, College of Physicians and Surgeons, Columbia University, New York, NY
| | - Ravichandran Ramasamy
- Diabetes Research Program, Division of Endocrinology, Department of Medicine, New York University School of Medicine, New York, NY
| | - Ann Marie Schmidt
- Diabetes Research Program, Division of Endocrinology, Department of Medicine, New York University School of Medicine, New York, NY
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Koulis C, Watson A, Gray S, Jandeleit-Dahm K. Linking RAGE and Nox in diabetic micro- and macrovascular complications. DIABETES & METABOLISM 2015; 41:272-281. [DOI: 10.1016/j.diabet.2015.01.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 01/24/2015] [Accepted: 01/30/2015] [Indexed: 12/31/2022]
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Guo L, Chen Z, Amarnath V, Yancey PG, Van Lenten BJ, Savage JR, Fazio S, Linton MF, Davies SS. Isolevuglandin-type lipid aldehydes induce the inflammatory response of macrophages by modifying phosphatidylethanolamines and activating the receptor for advanced glycation endproducts. Antioxid Redox Signal 2015; 22:1633-45. [PMID: 25751734 PMCID: PMC4485367 DOI: 10.1089/ars.2014.6078] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
AIMS Increased lipid peroxidation occurs in many conditions associated with inflammation. Because lipid peroxidation produces lipid aldehydes that can induce inflammatory responses through unknown mechanisms, elucidating these mechanisms may lead to development of better treatments for inflammatory diseases. We recently demonstrated that exposure of cultured cells to lipid aldehydes such as isolevuglandins (IsoLG) results in the modification of phosphatidylethanolamine (PE). We therefore sought to determine (i) whether PE modification by isolevuglandins (IsoLG-PE) occurred in vivo, (ii) whether IsoLG-PE stimulated the inflammatory responses of macrophages, and (iii) the identity of receptors mediating the inflammatory effects of IsoLG-PE. RESULTS IsoLG-PE levels were elevated in plasma of patients with familial hypercholesterolemia and in the livers of mice fed a high-fat diet to induce obesity and hepatosteatosis. IsoLG-PE potently stimulated nuclear factor kappa B (NFκB) activation and expression of inflammatory cytokines in macrophages. The effects of IsoLG-PE were blocked by the soluble form of the receptor for advanced glycation endproducts (sRAGE) and by RAGE antagonists. Furthermore, macrophages derived from the bone marrow of Ager null mice failed to express inflammatory cytokines in response to IsoLG-PE to the same extent as macrophages from wild-type mice. INNOVATION These studies are the first to identify IsoLG-PE as a mediator of macrophage activation and a specific receptor, RAGE, which mediates its biological effects. CONCLUSION PE modification by IsoLG forms RAGE ligands that activate macrophages, so that the increased IsoLG-PE generated by high circulating cholesterol levels or high-fat diet may play a role in the inflammation associated with these conditions.
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Affiliation(s)
- Lilu Guo
- 1Division of Clinical Pharmacology, Vanderbilt University at Nashville, Nashville, Tennessee
| | - Zhongyi Chen
- 1Division of Clinical Pharmacology, Vanderbilt University at Nashville, Nashville, Tennessee
| | | | - Patricia G Yancey
- 3Department of Medicine, Vanderbilt University at Nashville, Nashville, Tennessee
| | - Brian J Van Lenten
- 4Division of Cardiology, Department of Medicine, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
| | | | - Sergio Fazio
- 6Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - MacRae F Linton
- 3Department of Medicine, Vanderbilt University at Nashville, Nashville, Tennessee.,7Department of Pharmacology, Vanderbilt University at Nashville, Nashville, Tennessee
| | - Sean S Davies
- 1Division of Clinical Pharmacology, Vanderbilt University at Nashville, Nashville, Tennessee.,7Department of Pharmacology, Vanderbilt University at Nashville, Nashville, Tennessee.,8Vanderbilt Institute of Chemical Biology, Vanderbilt University at Nashville, Nashville, Tennessee
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Zhong Y, Cheng CF, Luo YZ, Tian CW, Yang H, Liu BR, Chen MS, Chen YF, Liu SM. C-reactive protein stimulates RAGE expression in human coronary artery endothelial cells in vitro via ROS generation and ERK/NF-κB activation. Acta Pharmacol Sin 2015; 36:440-7. [PMID: 25832424 DOI: 10.1038/aps.2014.163] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 12/09/2014] [Indexed: 12/27/2022] Open
Abstract
AIM The receptor for advanced glycation end-products (RAGE) plays an important role in development of atherosclerosis, and C-reactive protein (CRP) has been found to stimulate its expression in endothelial cells. In this study we investigated how CRP regulated the expression of RAGE in human coronary artery endothelial cells (HCAECs). METHODS HCAECs were treated in vitro with CRP (50 μg/mL) in combination with a variety of inhibitors. ROS generation was determined by immunocytochemistry and flow cytometry. The RAGE expression and phosphorylation of relevant signaling proteins were measured using Western blot analyses. RESULTS CRP stimulated the expression of RAGE in the cells, accompanied by markedly increased ROS generation, phosphorylation of ERK1/2 and NF-κB p65, as well as translocation of NF-κB p65 to the nuclei. CRP also stimulated phosphorylation of JNK and p38 MAPK. Pretreatment of the cells with the ROS scavenger N-acetyl-L-cysteine, ERK inhibitor PD98059 or NF-κB inhibitor PDTC blocked CRP-stimulated RAGE expression, but pretreatment with the NADPH oxidase inhibitor DPI, JNK inhibitor SP600125 or p38 MAPK inhibitor SB203580 did not significantly alter CRP-stimulated RAGE expression. CONCLUSION CRP stimulates RAGE expression in HCAECs in vitro via ROS generation and activation of the ERK/NF-κB signaling pathway.
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Role of bone-marrow- and non-bone-marrow-derived receptor for advanced glycation end-products (RAGE) in a mouse model of diabetes-associated atherosclerosis. Clin Sci (Lond) 2014; 127:485-97. [PMID: 24724734 DOI: 10.1042/cs20140045] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
RAGE (receptor for advanced glycation end-products) is expressed on multiple cell types implicated in the progression of atherosclerosis and plays a role in DAA (diabetes-associated atherosclerosis). The aim of the present study was to determine the relative role of either BM (bone marrow)- or non-BM-derived RAGE in the pathogenesis of STZ (streptozotocin)-induced DAA. Male ApoE (apolipoprotein E)-null (ApoE-/-:RAGE+/+) and ApoE:RAGE-null (ApoE-/-:RAGE-/-) mice at 7 weeks of age were rendered diabetic with STZ. At 8 weeks of age, ApoE-/- and ApoE-/-:RAGE-/- control and diabetic mice received BM from either RAGE-null or RAGE-bearing mice, generating various chimaeras. After 10 and 20 weeks of diabetes, mice were killed and gene expression and atherosclerotic lesion formation were evaluated respectively. Deletion of RAGE in either the BM cells or non-BM cells both resulted in a significant attenuation in DAA, which was associated with reduced VCAM-1 (vascular cell adhesion molecule-1) expression and translated into reduced adhesion in vitro. In conclusion, the results of the present study highlight the importance of both BM- and non-BM-derived RAGE in attenuating the development of DAA.
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12
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Tesch G, Sourris KC, Summers SA, McCarthy D, Ward MS, Borg DJ, Gallo LA, Fotheringham AK, Pettit AR, Yap FYT, Harcourt BE, Tan ALY, Kausman JY, Nikolic-Paterson D, Kitching AR, Forbes JM. Deletion of bone-marrow-derived receptor for AGEs (RAGE) improves renal function in an experimental mouse model of diabetes. Diabetologia 2014; 57:1977-85. [PMID: 24957662 DOI: 10.1007/s00125-014-3291-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 05/09/2014] [Indexed: 01/11/2023]
Abstract
AIMS/HYPOTHESIS The AGEs and the receptor for AGEs (RAGE) are known contributors to diabetic complications. RAGE also has a physiological role in innate and adaptive immunity and is expressed on immune cells. The aim of this study was to determine whether deletion of RAGE from bone-marrow-derived cells influences the pathogenesis of experimental diabetic nephropathy. METHODS Groups (n = 8/group) of lethally irradiated 8 week old wild-type (WT) mice were reconstituted with bone marrow from WT (WT → WT) or RAGE-deficient (RG) mice (RG → WT). Diabetes was induced using multiple low doses of streptozotocin after 8 weeks of bone marrow reconstitution and mice were followed for a further 24 weeks. RESULTS Compared with diabetic WT mice reconstituted with WT bone marrow, diabetic WT mice reconstituted with RG bone marrow had lower urinary albumin excretion and podocyte loss, more normal creatinine clearance and less tubulo-interstitial injury and fibrosis. However, glomerular collagen IV deposition, glomerulosclerosis and cortical levels of TGF-β were not different among diabetic mouse groups. The renal tubulo-interstitium of diabetic RG → WT mice also contained fewer infiltrating CD68(+) macrophages that were activated. Diabetic RG → WT mice had lower renal cortical concentrations of CC chemokine ligand 2 (CCL2), macrophage inhibitory factor (MIF) and IL-6 than diabetic WT → WT mice. Renal cortical RAGE ligands S100 calgranulin (S100A)8/9 and AGEs, but not high mobility box protein B-1 (HMGB-1) were also decreased in diabetic RG → WT compared with diabetic WT → WT mice. In vitro, bone-marrow-derived macrophages from WT but not RG mice stimulated collagen IV production in cultured proximal tubule cells. CONCLUSIONS/INTERPRETATION These studies suggest that RAGE expression on haemopoietically derived immune cells contributes to the functional changes seen in diabetic nephropathy by promoting macrophage infiltration and renal tubulo-interstitial damage.
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Affiliation(s)
- Greg Tesch
- Department of Nephrology, Monash Medical Centre, Monash Health, Clayton, Melbourne, VIC, Australia
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13
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Cellular signalling of the receptor for advanced glycation end products (RAGE). Cell Signal 2013; 25:2185-97. [DOI: 10.1016/j.cellsig.2013.06.013] [Citation(s) in RCA: 347] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 06/15/2013] [Accepted: 06/25/2013] [Indexed: 01/03/2023]
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Kikuchi K, Tancharoen S, Ito T, Morimoto-Yamashita Y, Miura N, Kawahara KI, Maruyama I, Murai Y, Tanaka E. Potential of the angiotensin receptor blockers (ARBs) telmisartan, irbesartan, and candesartan for inhibiting the HMGB1/RAGE axis in prevention and acute treatment of stroke. Int J Mol Sci 2013; 14:18899-924. [PMID: 24065095 PMCID: PMC3794813 DOI: 10.3390/ijms140918899] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 09/07/2013] [Accepted: 09/09/2013] [Indexed: 12/29/2022] Open
Abstract
Stroke is a major cause of mortality and disability worldwide. The main cause of stroke is atherosclerosis, and the most common risk factor for atherosclerosis is hypertension. Therefore, antihypertensive treatments are recommended for the prevention of stroke. Three angiotensin receptor blockers (ARBs), telmisartan, irbesartan and candesartan, inhibit the expression of the receptor for advanced glycation end-products (RAGE), which is one of the pleiotropic effects of these drugs. High mobility group box 1 (HMGB1) is the ligand of RAGE, and has been recently identified as a lethal mediator of severe sepsis. HMGB1 is an intracellular protein, which acts as an inflammatory cytokine when released into the extracellular milieu. Extracellular HMGB1 causes multiple organ failure and contributes to the pathogenesis of hypertension, hyperlipidemia, diabetes mellitus, atherosclerosis, thrombosis, and stroke. This is the first review of the literature evaluating the potential of three ARBs for the HMGB1-RAGE axis on stroke therapy, including prevention and acute treatment. This review covers clinical and experimental studies conducted between 1976 and 2013. We propose that ARBs, which inhibit the HMGB1/RAGE axis, may offer a novel option for prevention and acute treatment of stroke. However, additional clinical studies are necessary to verify the efficacy of ARBs.
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Affiliation(s)
- Kiyoshi Kikuchi
- Department of Pharmacology, Faculty of Dentistry, Mahidol University, 6 Yothe Road, Rajthevee, Bangkok 10400, Thailand; E-Mails: (K.K.); (S.T.)
- Division of Brain Science, Department of Physiology, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011, Japan; E-Mail:
- Department of Neurosurgery, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011, Japan
| | - Salunya Tancharoen
- Department of Pharmacology, Faculty of Dentistry, Mahidol University, 6 Yothe Road, Rajthevee, Bangkok 10400, Thailand; E-Mails: (K.K.); (S.T.)
| | - Takashi Ito
- Department of Systems Biology in Thromboregulation, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan; E-Mails: (T.I.); (I.M.)
| | - Yoko Morimoto-Yamashita
- Department of Restorative Dentistry and Endodontology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan; E-Mail:
| | - Naoki Miura
- Laboratory of Diagnostic Imaging, Department of Veterinary Science, Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan; E-Mail:
| | - Ko-ichi Kawahara
- Laboratory of Functional Foods, Department of Biomedical Engineering Osaka Institute of Technology, 5-16-1 Omiya, Asahi Ward, Osaka 535-8585, Japan; E-Mail:
| | - Ikuro Maruyama
- Department of Systems Biology in Thromboregulation, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan; E-Mails: (T.I.); (I.M.)
| | - Yoshinaka Murai
- Division of Brain Science, Department of Physiology, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011, Japan; E-Mail:
| | - Eiichiro Tanaka
- Division of Brain Science, Department of Physiology, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011, Japan; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +81-942-31-7542; Fax: +81-942-31-7695
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RAGE-mediated interstitial fibrosis in neonatal obstructive nephropathy is independent of NF-κB activation. Kidney Int 2013; 84:911-9. [PMID: 23677242 DOI: 10.1038/ki.2013.171] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 02/10/2013] [Accepted: 02/14/2013] [Indexed: 11/08/2022]
Abstract
Urinary tract obstruction during nephron development causes tubular apoptosis, tubular atrophy, and interstitial fibrosis. Leukocyte recruitment is critical in the development of obstructive nephropathy leading to interstitial inflammation and renal fibrosis. RAGE, the receptor of advanced glycation end products, is implicated in chronic inflammation and has been recently identified as a novel receptor for the β2-integrin Mac-1, cooperating with ICAM-1 and thereby directly mediating leukocyte recruitment in vivo. Here, we studied the role of RAGE and ICAM-1 in a model of unilateral ureteral obstruction in neonatal mice. Interestingly, the number of infiltrating leukocytes was independent of RAGE and ICAM-1 in the ureteral obstructed neonatal kidney. By contrast, galectin-3, a marker for profibrogenic M2 macrophages, was strongly reduced in ureteral obstructed RAGE and RAGE-Icam1 knockout mice. Snail expression and loss of E-cadherin but not NF-κB activation were attenuated in both knockout models. Epithelial cell cycle arrest at G2/M, which mediates kidney fibrosis, and transforming growth factor-β expression were reduced in ureteral obstructed RAGE knockout mice. Thus, RAGE and ICAM-1 promote renal fibrosis in the developing kidney upon ureteral obstruction. Combined RAGE- and ICAM-1-blocking strategies may prove beneficial in neonatal obstructive nephropathy.
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Sternberg Z, Ghanim H, Gillotti KM, Tario JD, Munschauer F, Curl R, Noor S, Yu J, Ambrus JL, Wallace P, Dandona P. Flow cytometry and gene expression profiling of immune cells of the carotid plaque and peripheral blood. Atherosclerosis 2013; 229:338-47. [PMID: 23880185 DOI: 10.1016/j.atherosclerosis.2013.04.035] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 04/08/2013] [Accepted: 04/26/2013] [Indexed: 10/26/2022]
Abstract
OBJECTIVES The relative contribution of the local vs. peripheral inflammation to the atherothrombotic processes is unknown. We compared the inflammatory status of the immune cells of the carotid plaque with similar cells in peripheral circulation of patients with advanced carotid disease (PCDs). METHODS Mononuclear cells (MNCs) were extracted from carotid endarterectomy (CEA) samples by enzymatic digestion and subsequent magnetic cell sorting. The cell surface antigenic expressions, and mRNA expression levels were compared between CEA MNCs and peripheral MNCs, using flow cytometry and RT-PCR techniques. RESULTS The percentages of resting MNCs were lower, and activated MNCs, particularly monocytes, were higher in the CEAMNCs, as compared to the peripheral MNCs. The percentages of activated T cells and B cells were higher in the peripheral MNCs of PCDs, than in healthy controls (HCs), but the percentages of activated monocytes did not differ between the two groups. The expression levels of both pro-inflammatory/pro-thrombotic (P(38), JNKB-1, Egr-1 PAI-1, MCP-1, TF, MMP-9, HMGB-1, TNF-α, mTOR) and anti-inflammatory (PPAR-γ, TGF-β) mediators were significantly higher in the CEA MNCs as compared to the peripheral MNCs. Furthermore, MMP-9 and PPAR-γ expression levels were higher in the peripheral MNCs of PCDs than HCs. CONCLUSION The inflammatory status is higher in the immune cells of the carotid plaque, as compared to those cells in the peripheral blood. The altered expression levels of both pro-inflammatory/pro-thrombotic and anti-inflammatory mediators in the milieu of the plaque suggest that the balance between these various mediators may play a key role in carotid disease progression.
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Nagareddy PR, Murphy AJ, Stirzaker RA, Hu Y, Yu S, Miller RG, Ramkhelawon B, Distel E, Westerterp M, Huang LS, Schmidt AM, Orchard TJ, Fisher EA, Tall AR, Goldberg IJ. Hyperglycemia promotes myelopoiesis and impairs the resolution of atherosclerosis. Cell Metab 2013; 17:695-708. [PMID: 23663738 PMCID: PMC3992275 DOI: 10.1016/j.cmet.2013.04.001] [Citation(s) in RCA: 432] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 02/19/2013] [Accepted: 03/29/2013] [Indexed: 01/06/2023]
Abstract
Diabetes is a major risk factor for atherosclerosis. Although atherosclerosis is initiated by deposition of cholesterol-rich lipoproteins in the artery wall, the entry of inflammatory leukocytes into lesions fuels disease progression and impairs resolution. We show that diabetic mice have increased numbers of circulating neutrophils and Ly6-C(hi) monocytes, reflecting hyperglycemia-induced proliferation and expansion of bone marrow myeloid progenitors and release of monocytes into the circulation. Increased neutrophil production of S100A8/S100A9, and its subsequent interaction with the receptor for advanced glycation end products on common myeloid progenitor cells, leads to enhanced myelopoiesis. Treatment of hyperglycemia reduces monocytosis, entry of monocytes into atherosclerotic lesions, and promotes regression. In patients with type 1 diabetes, plasma S100A8/S100A9 levels correlate with leukocyte counts and coronary artery disease. Thus, hyperglycemia drives myelopoiesis and promotes atherogenesis in diabetes.
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Affiliation(s)
- Prabhakara R Nagareddy
- Division of Preventive Medicine and Nutrition, Department of Medicine, Columbia University, New York, NY 10032, USA
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Asavarut P, Zhao H, Gu J, Ma D. The role of HMGB1 in inflammation-mediated organ injury. ACTA ACUST UNITED AC 2013; 51:28-33. [PMID: 23711603 DOI: 10.1016/j.aat.2013.03.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 10/29/2012] [Accepted: 11/01/2012] [Indexed: 02/09/2023]
Abstract
HMGB1 is a chromosome-binding protein that also acts as a damage-associated molecular pattern molecule. It has potent proinflammatory effects and is one of key mediators of organ injury. Evidence from research has revealed its involvement in the signaling mechanisms of Toll-like receptors and the receptor for advanced glycation end-products in organ injury. HMGB1-mediated organ injuries are acute damage including ischemic, mechanical, allograft rejection and toxicity, and chronic diseases of the heart, kidneys, lungs, and brain. Strategies against HMGB1 and its associated cellular signal pathways need to be developed and may have preventive and therapeutic potentials in organ injury.
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Affiliation(s)
- Paladd Asavarut
- Section of Anaesthetics, Pain Medicine & Intensive Care, Department of Surgery and Cancer, Imperial College London, Chelsea and Westminster Hospital, London, UK
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Tetramethylpyrazine Attenuates Atherosclerosis Development and Protects Endothelial Cells from ox-LDL. Cardiovasc Drugs Ther 2013; 27:199-210. [DOI: 10.1007/s10557-013-6440-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Ramasamy R, Yan SF, Schmidt AM. The diverse ligand repertoire of the receptor for advanced glycation endproducts and pathways to the complications of diabetes. Vascul Pharmacol 2012; 57:160-7. [PMID: 22750165 DOI: 10.1016/j.vph.2012.06.004] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 06/20/2012] [Accepted: 06/21/2012] [Indexed: 02/06/2023]
Abstract
The multi-ligand receptor RAGE was discovered on account of its ability to bind and transduce the cell stress-provoking signals of advanced glycation endproducts (AGEs). The finding that RAGE also bound pro-inflammatory molecules set the stage for linking RAGE and inflammation to the pathogenesis of diabetic macro- and microvascular complications. In this review, we focus on the roles of RAGE and its ligands in diabetes complications. We recount the findings from mice, rats, swine and human subjects suggesting that RAGE action potently contributes to vascular, inflammatory and end-organ stress and damage in types 1 and 2 diabetes. We detail the efforts to track ligands and RAGE in human subjects with diabetes to address if this axis may be a biomarker reflective of the state of the diabetic complications. Lastly, we suggest specific strategies to tackle AGE-ligand-RAGE interactions as potential therapeutic targets for diabetes and its complications.
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Affiliation(s)
- Ravichandran Ramasamy
- Diabetes Research Program, Division of Endocrinology, Department of Medicine, New York University School of Medicine, New York, NY 10016, United States
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Ramasamy R, Yan SF, Schmidt AM. Receptor for AGE (RAGE): signaling mechanisms in the pathogenesis of diabetes and its complications. Ann N Y Acad Sci 2012; 1243:88-102. [PMID: 22211895 DOI: 10.1111/j.1749-6632.2011.06320.x] [Citation(s) in RCA: 349] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The receptor for advanced glycation endproducts (RAGE) was first described as a signal transduction receptor for advanced glycation endproducts (AGEs), the products of nonenzymatic glycation and oxidation of proteins and lipids that accumulate in diabetes and in inflammatory foci. The discovery that RAGE was a receptor for inflammatory S100/calgranulins and high mobility group box 1 (HMGB1) set the stage for linking RAGE to both the consequences and causes of types 1 and 2 diabetes. Recent discoveries regarding the structure of RAGE as well as novel intracellular binding partner interactions advance our understanding of the mechanisms by which RAGE evokes pathological consequences and underscore strategies by which antagonism of RAGE in the clinic may be realized. Finally, recent data tracking RAGE in the clinic suggest that levels of soluble RAGEs and polymorphisms in the gene encoding RAGE may hold promise for the identification of patients who are vulnerable to the complications of diabetes and/or are receptive to therapeutic interventions designed to prevent and reverse the damage inflicted by chronic hyperglycemia, irrespective of its etiology.
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Affiliation(s)
- Ravichandran Ramasamy
- Diabetes Research Program, Division of Endocrinology, Department of Medicine, New York University School of Medicine, New York, New York 10016, USA
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Wang Z, Jiang Y, Liu N, Ren L, Zhu Y, An Y, Chen D. Advanced glycation end-product Nε-carboxymethyl-Lysine accelerates progression of atherosclerotic calcification in diabetes. Atherosclerosis 2012; 221:387-96. [PMID: 22305260 DOI: 10.1016/j.atherosclerosis.2012.01.019] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 12/24/2011] [Accepted: 01/09/2012] [Indexed: 01/03/2023]
Abstract
OBJECTIVE Vascular calcification is an active deposition process of calcium phosphate which resembles bone formation and is highly regulated by osteoblast-like cells. Existing studies demonstrate that advanced glycation end-products (AGEs) may play a pathogenic role in the vascular calcification process. However, their mechanism remains poorly understood. The aim of our current study is to investigate how non-cross-link and non-fluorescent N(ε)-carboxymethyl-Lysine (CML), a major immunogen of AGEs, affect the progression of atherosclerotic calcification in diabetes. METHODS The present study consisted of an in vivo investigation and two in vitro investigations. In study I, male apoE(-/-) mice were first rendered diabetic by the administration of 5 daily intraperitoneal injections of streptozotocin (STZ, 40 mg/kg), and then given a semi-synthetic high-fat diet (HFD) plus daily injections of CML (10mg/kg/day). The mice were euthanized and analyzed at 0 month (group 0M, n = 10), 2 months (group 2M, n = 10), and 4 months (group 4M, n = 10) after the triple administrations of STZ-CML-HFD. In study II, the effects of CML on the apoptosis in macrophages were investigated. RAW264.7 cells were incubated with or without 50 μg/mL oxLDL plus various concentrations of CML for 48 h. In study III, we investigated whether A7r5 aortic smooth muscle cells were induced into osteoblast-like phenotypes by incubation with or without 80 μg/mL of RAW264.7-derived-apoptotic bodies and 50 μg/mL of oxLDL plus various concentrations of CML (or high-glucose) for 7 days. Related analyses (i.e., H&E staining, Masson staining, von Kossa staining, TUNEL staining, immunohistochemical staining, calcium content assay, annexin V-FITC/PI double-staining, and Western blot) were performed. RESULTS Morphological analysis showed that early atherosclerotic plaques appeared 2 months after the triple administrations of STZ-CML-HFD, and that typically advanced plaques with extensive calcification lesions, abundant cholesterol crystals, and proliferative collagen were formed 4 months after the triple administrations of STZ-CML-HFD. Furthermore, CML deposition signals and the expression of receptor for advanced glycation end-products (RAGE) in the aortic wall were mainly restricted in the atherosclerotic plaques. After the incubation of A7r5 smooth muscle cells with 10 μmol/L CML plus 50 μg/mL oxLDL, and 80 μg/mL apoptotic bodies (ABs) for 7 days, semi-quantitative analysis of bone morphogenetic protein 2 (BMP-2), core-binding factor α1 (cbfα1), and alkaline phosphatase (ALP) expression showed 5.0-, 2.0-, and 2.9-fold increases, respectively, compared with those in 50 μg/mL oxLDL and 80 μg/mL ABs. Subsequently, a similar trend was observed in the calcium deposition of the cell layer. However, high-glucose had no effects on the ALP activity and calcium deposition of A7r5 cell layer under high-lipid, apoptosis-coexisting conditions. Both animal and cell studies consistently demonstrated that the CML/RAGE axis may first initiate the apoptosis of macrophages in atherosclerotic lesions and then induce BMP-2-cbfα1-ALP-calcification cascade in a high-lipid, apoptosis-coexisting environment. CONCLUSION The CML/RAGE axis may play an important role in atherosclerotic calcification of diabetes through the mechanism that induces the apoptosis of macrophages followed by the osteogenic differentiation of aortic smooth muscle cells.
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Affiliation(s)
- Zhongqun Wang
- Department and Institute of Cardiology, Zhongda Hospital, Southeast University, Nanjing 210009, China
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Bornfeldt KE, Tabas I. Insulin resistance, hyperglycemia, and atherosclerosis. Cell Metab 2011; 14:575-85. [PMID: 22055501 PMCID: PMC3217209 DOI: 10.1016/j.cmet.2011.07.015] [Citation(s) in RCA: 562] [Impact Index Per Article: 43.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 07/13/2011] [Accepted: 07/27/2011] [Indexed: 12/16/2022]
Abstract
Progress in preventing atherosclerotic coronary artery disease (CAD) has been stalled by the epidemic of type 2 diabetes. Further advances in this area demand a thorough understanding of how two major features of type 2 diabetes, insulin resistance and hyperglycemia, impact atherosclerosis. Insulin resistance is associated with systemic CAD risk factors, but increasing evidence suggests that defective insulin signaling in atherosclerotic lesional cells also plays an important role. The role of hyperglycemia in CAD associated with type 2 diabetes is less clear. Understanding the mechanisms whereby type 2 diabetes exacerbates CAD offers hope for new therapeutic strategies to prevent and treat atherosclerotic vascular disease.
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Affiliation(s)
- Karin E Bornfeldt
- Department of Pathology, Diabetes and Obesity Center of Excellence, 815 Mercer Street, University of Washington, Seattle, WA 98109, USA
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