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Chandrasekar B, Mummidi S, DeMarco VG, Higashi Y. Empagliflozin Reverses Oxidized LDL-Induced RECK Suppression, Cardiotrophin-1 Expression, MMP Activation, and Human Aortic Smooth Muscle Cell Proliferation and Migration. Mediators Inflamm 2023; 2023:6112301. [PMID: 37830075 PMCID: PMC10567511 DOI: 10.1155/2023/6112301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/04/2023] [Accepted: 09/07/2023] [Indexed: 10/14/2023] Open
Abstract
Persistent oxidative stress and inflammation contribute causally to smooth muscle cell (SMC) proliferation and migration, the characteristic features of vascular proliferative diseases. Oxidatively modified low-density lipoproteins (OxLDL) elevate oxidative stress levels, inflammatory responses, and matrix metallopeptidase (MMP) activation, resulting ultimately in SMC migration, proliferation, and phenotype change. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK) is a membrane-anchored MMP inhibitor. Empagliflozin is an SGLT2 inhibitor and exerts pleiotropic cardiovascular protective effects, including antioxidant and anti-inflammatory effects. Here, we investigated (i) whether OxLDL regulates RECK expression, (ii) whether ectopic expression of RECK reverses OxLDL-induced SMC migration and proliferation, and (iii) whether pretreatment with empagliflozin reverses OxLDL-induced RECK suppression, MMP activation, and SMC migration, proliferation, and differentiation. Indeed, results show that OxLDL at pathophysiological concentration promotes SMC migration and proliferation via NF-κB/miR-30b-dependent RECK suppression. Moreover, OxLDL changed the SMC phenotype to a more pro-inflammatory type, and this effect is blunted by RECK overexpression. Further, treatment with empagliflozin reversed OxLDL-induced miR-30b induction, RECK suppression, MMP activation, SMC migration, proliferation, and proinflammatory phenotype changes. OxLDL-induced cardiotrophin (CT)-1 expression and CT-1 stimulated SMC proliferation and migration in part via leukemia inhibitory factor receptor (LIFR) and glycoprotein 130 (gp130). Ectopic expression of RECK inhibited these effects by physically associating with LIFR and gp130, as evidenced by immunoprecipitation/immunoblotting and double immunofluorescence. Importantly, empagliflozin inhibited CT-1-induced mitogenic and migratory effects. Together, these results suggest the therapeutic potential of sustaining RECK expression or empagliflozin in vascular diseases characterized by SMC proliferation and migration.
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Affiliation(s)
- Bysani Chandrasekar
- Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO, USA
- Medicine, University of Missouri School of Medicine, Columbia, MO, USA
- Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
- Dalton Cardiovascular Center, University of Missouri, Columbia, MO, USA
| | - Srinivas Mummidi
- Life Sciences, Texas A&M University-San Antonio, San Antonio, TX, USA
| | - Vincent G. DeMarco
- Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO, USA
- Medicine, University of Missouri School of Medicine, Columbia, MO, USA
- Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
| | - Yusuke Higashi
- Medicine/Cardiology, Tulane University School of Medicine, New Orleans, LA, USA
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Ghodsian N, Yeandle A, Hock BD, Gieseg SP. CD36 down regulation by the macrophage antioxidant 7,8-dihydroneopterin through modulation of PPAR-γ activity. Free Radic Res 2022; 56:366-377. [PMID: 36017639 DOI: 10.1080/10715762.2022.2114904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
CD36 is the key scavenger receptor driving the formation of cholesterol loaded foam cells, the principal cellular component of atherosclerotic plaques. CD36 is down regulated by 7,8-dihydroneopterin, a potent superoxide and hypochlorite scavenging antioxidant generated by interferon-γ stimulated macrophages. 7,8-dihydroneopterin down regulates CD36 mRNA and protein levels so inhibiting macrophage foam cell formation in vitro.We examined the mechanism of 7,8-dihydroneopterin down regulation of CD36 by measuring CD36 and PPAR-γ levels by western blot analysis, in the monocyte-like U937 cells with a range of PPAR-γ stimulants and inhibitors. Lipoxygenase activity was measured by monitoring linoleic acid oxidation at 234 nm for diene formation.Between 100 and 200 μM, 7,8-dihydroneopterin decreased CD36 levels by 50% within 12 hours with levels dropping below 25% by 24 hours. CD36 levels returned to basal levels after 24 hours. Inhibition of protein synthesis by cycloheximide show 7,8-dihydroneopterin had no effect on CD36 degradation rates. PPAR-γ levels were not altered by the addition of 7,8-dihydroneopterin. MAP Kinase, P38 and NF-κB pathways inhibitors SP600125, PD98059, SB202190 and BAY 11-7082 respectively, did not restore the CD36 levels in the presence of 7,8-dihydroneopterin. The addition the lipophilic PPAR-γ activators rosiglitazone and azelaoyl-PAF prevented the CD36 down regulation by 7,8-dihydroneopterin. 7,8-dihydroneopterin inhibited soybean lipoxygenase and reduced U937 cell basal levels of cellular lipid oxides as measured by HPLC-TBARS analysis.The data shows 7,8-dihydroneopterin down regulates CD36 expression by decreasing the level of lipid oxide stimulation of PPAR-γ promotor activity, potentially through lipoxygenase inhibition.
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Affiliation(s)
- Nooshin Ghodsian
- Free Radical Biochemistry, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Anthony Yeandle
- Free Radical Biochemistry, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Barry D Hock
- Haematology Research Group, Christchurch Hospital, New Zealand
| | - Steven P Gieseg
- Free Radical Biochemistry, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.,Department of Radiology, University of Otago Christchurch, New Zealand.,MARS Bioimaging Ltd., 29a Clyde Rd, Christchurch 8140, New Zealand
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3
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Beneit N, Martín-Ventura JL, Rubio-Longás C, Escribano Ó, García-Gómez G, Fernández S, Sesti G, Hribal ML, Egido J, Gómez-Hernández A, Benito M. Potential role of insulin receptor isoforms and IGF receptors in plaque instability of human and experimental atherosclerosis. Cardiovasc Diabetol 2018; 17:31. [PMID: 29463262 PMCID: PMC5819698 DOI: 10.1186/s12933-018-0675-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 02/12/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Clinical complications associated with atherosclerotic plaques arise from luminal obstruction due to plaque growth or destabilization leading to rupture. We previously demonstrated that overexpression of insulin receptor isoform A (IRA) and insulin-like growth factor-I receptor (IGF-IR) confers a proliferative and migratory advantage to vascular smooth muscle cells (VSMCs) promoting plaque growth in early stages of atherosclerosis. However, the role of insulin receptor (IR) isoforms, IGF-IR or insulin-like growth factor-II receptor (IGF-IIR) in VSMCs apoptosis during advanced atherosclerosis remains unclear. METHODS We evaluated IR isoforms expression in human carotid atherosclerotic plaques by consecutive immunoprecipitations of insulin receptor isoform B (IRB) and IRA. Western blot analysis was performed to measure IGF-IR, IGF-IIR, and α-smooth muscle actin (α-SMA) expression in human plaques. The expression of those proteins, as well as the presence of apoptotic cells, was analyzed by immunohistochemistry in experimental atherosclerosis using BATIRKO; ApoE-/- mice, a model showing more aggravated vascular damage than ApoE-/- mice. Finally, apoptosis of VSMCs bearing IR (IRLoxP+/+ VSMCs), or not (IR-/- VSMCs), expressing IRA (IRA VSMCs) or expressing IRB (IRB VSMCs), was assessed by Western blot against cleaved caspase 3. RESULTS We observed a significant decrease of IRA/IRB ratio in human complicated plaques as compared to non-complicated regions. Moreover, complicated plaques showed a reduced IGF-IR expression, an increased IGF-IIR expression, and lower levels of α-SMA indicating a loss of VSMCs. In experimental atherosclerosis, we found a significant decrease of IRA with an increased IRB expression in aorta from 24-week-old BATIRKO; ApoE-/- mice. Furthermore, atherosclerotic plaques from BATIRKO; ApoE-/- mice had less VSMCs content and higher number of apoptotic cells. In vitro experiments showed that IGF-IR inhibition by picropodophyllin induced apoptosis in VSMCs. Apoptosis induced by thapsigargin was lower in IR-/- VSMCs expressing higher IGF-IR levels as compared to IRLoxP+/+ VSMCs. Finally, IRB VSMCs are more prone to thapsigargin-induced apoptosis than IRA or IRLoxP+/+ VSMCs. CONCLUSIONS In advanced human atherosclerosis, a reduction of IRA/IRB ratio, decreased IGF-IR expression, or increased IGF-IIR may contribute to VSMCs apoptosis, promoting plaque instability and increasing the risk of plaque rupture and its clinical consequences.
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Affiliation(s)
- Nuria Beneit
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain.,Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain.,CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Madrid, Spain
| | - José Luis Martín-Ventura
- Vascular Research Lab, IIS-Fundación Jiménez Díaz-Autonoma University, Madrid, Spain.,CIBER of Cardiovascular Diseases (CIBERCV), Madrid, Spain
| | - Carlota Rubio-Longás
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain.,Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain.,CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Madrid, Spain
| | - Óscar Escribano
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain.,Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain.,CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Madrid, Spain
| | - Gema García-Gómez
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain.,Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain.,CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Madrid, Spain
| | - Silvia Fernández
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain.,Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain.,CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Madrid, Spain
| | - Giorgio Sesti
- Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Marta Letizia Hribal
- Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Jesús Egido
- CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Madrid, Spain.,Vascular Research Lab, IIS-Fundación Jiménez Díaz-Autonoma University, Madrid, Spain.,CIBER of Cardiovascular Diseases (CIBERCV), Madrid, Spain
| | - Almudena Gómez-Hernández
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain. .,Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain. .,CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Madrid, Spain.
| | - Manuel Benito
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain.,Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain.,CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Madrid, Spain
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Oxidation of Atg3 and Atg7 mediates inhibition of autophagy. Nat Commun 2018; 9:95. [PMID: 29311554 PMCID: PMC5758830 DOI: 10.1038/s41467-017-02352-z] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 11/22/2017] [Indexed: 11/17/2022] Open
Abstract
Macroautophagy (autophagy) is a crucial cellular stress response for degrading defective macromolecules and organelles, as well as providing bioenergetic intermediates during hypoxia and nutrient deprivation. Here we report a thiol-dependent process that may account for impaired autophagy during aging. This is through direct oxidation of key autophagy-related (Atg) proteins Atg3 and Atg7. When inactive Atg3 and Atg7 are protected from oxidation due to stable covalent interaction with their substrate LC3. This interaction becomes transient upon activation of Atg3 and Atg7 due to transfer of LC3 to phosphatidylethanolamine (lipidation), a process crucial for functional autophagy. However, loss in covalent-bound LC3 also sensitizes the catalytic thiols of Atg3 and Atg7 to inhibitory oxidation that prevents LC3 lipidation, observed in vitro and in mouse aorta. Here findings provide a thiol-dependent process for negatively regulating autophagy that may contribute to the process of aging, as well as therapeutic targets to regulate autophagosome maturation. A dysfunction of autophagy can be detected in aged tissues, but how this is regulated is unclear. Here, the authors show in vitro and in aged mice aorta, that inhibition of LC3 lipidation under conditions of oxidative stress causes oxidation of Atg3 and Atg7, preventing autophagosome maturation.
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André-Lévigne D, Modarressi A, Pepper MS, Pittet-Cuénod B. Reactive Oxygen Species and NOX Enzymes Are Emerging as Key Players in Cutaneous Wound Repair. Int J Mol Sci 2017; 18:ijms18102149. [PMID: 29036938 PMCID: PMC5666831 DOI: 10.3390/ijms18102149] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 10/09/2017] [Accepted: 10/10/2017] [Indexed: 02/07/2023] Open
Abstract
Our understanding of the role of oxygen in cell physiology has evolved from its long-recognized importance as an essential factor in oxidative metabolism to its recognition as an important player in cell signaling. With regard to the latter, oxygen is needed for the generation of reactive oxygen species (ROS), which regulate a number of different cellular functions including differentiation, proliferation, apoptosis, migration, and contraction. Data specifically concerning the role of ROS-dependent signaling in cutaneous wound repair are very limited, especially regarding wound contraction. In this review we provide an overview of the current literature on the role of molecular and reactive oxygen in the physiology of wound repair as well as in the pathophysiology and therapy of chronic wounds, especially under ischemic and hyperglycemic conditions.
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Affiliation(s)
- Dominik André-Lévigne
- Department of Plastic, Reconstructive & Aesthetic Surgery, University Hospitals of Geneva, 1205 Geneva, Switzerland.
| | - Ali Modarressi
- Department of Plastic, Reconstructive & Aesthetic Surgery, University Hospitals of Geneva, 1205 Geneva, Switzerland.
| | - Michael S Pepper
- Department of Human Genetics and Development, Faculty of Medicine, University of Geneva, 1206 Geneva, Switzerland.
- SAMRC Extramural Unit for Stem Cell Research and Therapy, and Institute for Cellular and Molecular Medicine, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria 0002, South Africa.
| | - Brigitte Pittet-Cuénod
- Department of Plastic, Reconstructive & Aesthetic Surgery, University Hospitals of Geneva, 1205 Geneva, Switzerland.
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Higashi Y, Sukhanov S, Shai SY, Danchuk S, Tang R, Snarski P, Li Z, Lobelle-Rich P, Wang M, Wang D, Yu H, Korthuis R, Delafontaine P. Insulin-Like Growth Factor-1 Receptor Deficiency in Macrophages Accelerates Atherosclerosis and Induces an Unstable Plaque Phenotype in Apolipoprotein E-Deficient Mice. Circulation 2016; 133:2263-78. [PMID: 27154724 DOI: 10.1161/circulationaha.116.021805] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 04/27/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND We have previously shown that systemic infusion of insulin-like growth factor-1 (IGF-1) exerts anti-inflammatory and antioxidant effects and reduces atherosclerotic burden in apolipoprotein E (Apoe)-deficient mice. Monocytes/macrophages express high levels of IGF-1 receptor (IGF1R) and play a pivotal role in atherogenesis, but the potential effects of IGF-1 on their function are unknown. METHODS AND RESULTS To determine mechanisms whereby IGF-1 reduces atherosclerosis and to explore the potential involvement of monocytes/macrophages, we created monocyte/macrophage-specific IGF1R knockout (MΦ-IGF1R-KO) mice on an Apoe(-/-) background. We assessed atherosclerotic burden, plaque features of stability, and monocyte recruitment to atherosclerotic lesions. Phenotypic changes of IGF1R-deficient macrophages were investigated in culture. MΦ-IGF1R-KO significantly increased atherosclerotic lesion formation, as assessed by Oil Red O staining of en face aortas and aortic root cross-sections, and changed plaque composition to a less stable phenotype, characterized by increased macrophage and decreased α-smooth muscle actin-positive cell population, fibrous cap thinning, and decreased collagen content. Brachiocephalic artery lesions of MΦ-IGF1R-KO mice had histological features implying plaque vulnerability. Macrophages isolated from MΦ-IGF1R-KO mice showed enhanced proinflammatory responses on stimulation by interferon-γ and oxidized low-density lipoprotein and elevated antioxidant gene expression levels. Moreover, IGF1R-deficient macrophages had decreased expression of ABCA1 and ABCG1 and reduced lipid efflux. CONCLUSIONS Our data indicate that macrophage IGF1R signaling suppresses macrophage and foam cell accumulation in lesions and reduces plaque vulnerability, providing a novel mechanism whereby IGF-1 exerts antiatherogenic effects.
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Affiliation(s)
- Yusuke Higashi
- From Departments of Medicine (Y.H., S.S., S.D., P.S., Z.L., P.D.) and Medical Pharmacology and Physiology (Y.H., S.S., M.W., D.W., H.Y., R.K.), University of Missouri School of Medicine, Columbia; and Department of Medicine, Tulane University School of Medicine, New Orleans, LA (S.-Y.S., R.T., P.L.-R.).
| | - Sergiy Sukhanov
- From Departments of Medicine (Y.H., S.S., S.D., P.S., Z.L., P.D.) and Medical Pharmacology and Physiology (Y.H., S.S., M.W., D.W., H.Y., R.K.), University of Missouri School of Medicine, Columbia; and Department of Medicine, Tulane University School of Medicine, New Orleans, LA (S.-Y.S., R.T., P.L.-R.)
| | - Shaw-Yung Shai
- From Departments of Medicine (Y.H., S.S., S.D., P.S., Z.L., P.D.) and Medical Pharmacology and Physiology (Y.H., S.S., M.W., D.W., H.Y., R.K.), University of Missouri School of Medicine, Columbia; and Department of Medicine, Tulane University School of Medicine, New Orleans, LA (S.-Y.S., R.T., P.L.-R.)
| | - Svitlana Danchuk
- From Departments of Medicine (Y.H., S.S., S.D., P.S., Z.L., P.D.) and Medical Pharmacology and Physiology (Y.H., S.S., M.W., D.W., H.Y., R.K.), University of Missouri School of Medicine, Columbia; and Department of Medicine, Tulane University School of Medicine, New Orleans, LA (S.-Y.S., R.T., P.L.-R.)
| | - Richard Tang
- From Departments of Medicine (Y.H., S.S., S.D., P.S., Z.L., P.D.) and Medical Pharmacology and Physiology (Y.H., S.S., M.W., D.W., H.Y., R.K.), University of Missouri School of Medicine, Columbia; and Department of Medicine, Tulane University School of Medicine, New Orleans, LA (S.-Y.S., R.T., P.L.-R.)
| | - Patricia Snarski
- From Departments of Medicine (Y.H., S.S., S.D., P.S., Z.L., P.D.) and Medical Pharmacology and Physiology (Y.H., S.S., M.W., D.W., H.Y., R.K.), University of Missouri School of Medicine, Columbia; and Department of Medicine, Tulane University School of Medicine, New Orleans, LA (S.-Y.S., R.T., P.L.-R.)
| | - Zhaohui Li
- From Departments of Medicine (Y.H., S.S., S.D., P.S., Z.L., P.D.) and Medical Pharmacology and Physiology (Y.H., S.S., M.W., D.W., H.Y., R.K.), University of Missouri School of Medicine, Columbia; and Department of Medicine, Tulane University School of Medicine, New Orleans, LA (S.-Y.S., R.T., P.L.-R.)
| | - Patricia Lobelle-Rich
- From Departments of Medicine (Y.H., S.S., S.D., P.S., Z.L., P.D.) and Medical Pharmacology and Physiology (Y.H., S.S., M.W., D.W., H.Y., R.K.), University of Missouri School of Medicine, Columbia; and Department of Medicine, Tulane University School of Medicine, New Orleans, LA (S.-Y.S., R.T., P.L.-R.)
| | - Meifang Wang
- From Departments of Medicine (Y.H., S.S., S.D., P.S., Z.L., P.D.) and Medical Pharmacology and Physiology (Y.H., S.S., M.W., D.W., H.Y., R.K.), University of Missouri School of Medicine, Columbia; and Department of Medicine, Tulane University School of Medicine, New Orleans, LA (S.-Y.S., R.T., P.L.-R.)
| | - Derek Wang
- From Departments of Medicine (Y.H., S.S., S.D., P.S., Z.L., P.D.) and Medical Pharmacology and Physiology (Y.H., S.S., M.W., D.W., H.Y., R.K.), University of Missouri School of Medicine, Columbia; and Department of Medicine, Tulane University School of Medicine, New Orleans, LA (S.-Y.S., R.T., P.L.-R.)
| | - Hong Yu
- From Departments of Medicine (Y.H., S.S., S.D., P.S., Z.L., P.D.) and Medical Pharmacology and Physiology (Y.H., S.S., M.W., D.W., H.Y., R.K.), University of Missouri School of Medicine, Columbia; and Department of Medicine, Tulane University School of Medicine, New Orleans, LA (S.-Y.S., R.T., P.L.-R.)
| | - Ronald Korthuis
- From Departments of Medicine (Y.H., S.S., S.D., P.S., Z.L., P.D.) and Medical Pharmacology and Physiology (Y.H., S.S., M.W., D.W., H.Y., R.K.), University of Missouri School of Medicine, Columbia; and Department of Medicine, Tulane University School of Medicine, New Orleans, LA (S.-Y.S., R.T., P.L.-R.)
| | - Patrice Delafontaine
- From Departments of Medicine (Y.H., S.S., S.D., P.S., Z.L., P.D.) and Medical Pharmacology and Physiology (Y.H., S.S., M.W., D.W., H.Y., R.K.), University of Missouri School of Medicine, Columbia; and Department of Medicine, Tulane University School of Medicine, New Orleans, LA (S.-Y.S., R.T., P.L.-R.)
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Shirpoor A, Norouzi L, Nemati S, Khadem Ansari MH. Protective effect of vitamin E against diabetes-induced oxidized LDL and aorta cell wall proliferation in rat. IRANIAN BIOMEDICAL JOURNAL 2016; 19:117-23. [PMID: 25864817 PMCID: PMC4412923 DOI: 10.6091/ibj.1449.2015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
UNLABELLED Hyperlipidemia and oxidized-low-density lipoproteins (Ox-LDL) are important independent cardiovascular risk factors that have been shown to stimulate vascular smooth muscle cell (VSMC) proliferation. The purpose of the present study was to investigate the effect of vitamin E on Ox-LDL, lipid profile, C-reactive protein (CRP), and VSMC proliferation of rat aorta. METHODS Male Wistar rats (n = 32) were divided into four groups namely: sham (SH), control (C), non-treated diabetic, and vitamin E-treated diabetic (VETD) groups. Ox-LDL, lipid profile, CRP and VSMC proliferation of aorta were measured after 42 days. RESULTS The results revealed that along with a significant increase in VSMC proliferation, the amount of CRP, Ox-LDL, and lipid profiles in diabetic rats. VSMC proliferation was significantly ameliorated, and elevated CRP, Ox-LDL, and lipid profiles were also restored to those of shams in VETD. CONCLUSIONS These findings strongly support the idea that diabetes induces Ox-LDL-mediated oxidative stress and VSMC proliferation in aorta of rat and imply that vitamin E has a strong protective effect as an antioxidant.
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Affiliation(s)
- Alireza Shirpoor
- Dept. of Physiology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Leila Norouzi
- Dept. of Physiology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Samira Nemati
- Dept. of Physiology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
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Autologous Bone Marrow Mononuclear Cell Transplantation Delays Progression of Carotid Atherosclerosis in Rabbits. Mol Neurobiol 2015; 53:4387-96. [PMID: 26232064 DOI: 10.1007/s12035-015-9347-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 07/07/2015] [Indexed: 10/23/2022]
Abstract
Bone marrow mononuclear cells (BMMNCs) can counteract oxidative stress and inhibit the inflammatory response in focal ischemic stroke models. However, the effect of BMMNC transplantation on carotid atherosclerosis needs to be determined. The carotid atherosclerotic plaque model was established in New Zealand White rabbits by balloon injury and 8 weeks of high-fat diet. Rabbits were randomized to receive an intravenous injection of autologous bromodeoxyuridine (BrdU)-labeled BMMNCs or an equal volume of phosphate-buffered saline. Plaques were evaluated for expression of proinflammatory and anti-inflammatory cytokines, anti-oxidant proteins, and markers of cell death. BMMNCs migrated into atherosclerotic plaque on the first day after cell transplantation. BMMNC-treated rabbits had smaller plaques and more collagen deposition than did the vehicle-treated controls on day 28 (p < 0.05). BMMNC treatment significantly increased endothelial nitric oxide synthase and the anti-oxidant enzymes glutathione peroxidase and superoxide dismutase in plaques compared to vehicle treatment on day 7. BMMNC-treated rabbits also had lower levels of cleaved caspase-3 expression; lower levels of proinflammatory cytokines interleukin-1β, tumor necrosis factor alpha, and matrix metalloproteinase 9; and higher levels of insulin-like growth factor-1 and its receptor (p < 0.05). Autologous BMMNC transplantation can suppress the process of atherosclerotic plaque formation and is associated with enhanced anti-oxidative effect, reduced levels of inflammatory cytokines and cleaved caspase-3, and increased expression of insulin-like growth factor-1 and its receptor. BMMNC transplantation represents a novel approach for the treatment of carotid atherosclerosis.
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CHENG YUNPENG, LIU XIAOYUN, ZHANG LIJIAO, ZHANG YING, LIU YING, LU YAN, JIANG YINONG. Effect of oxidized low-density lipoprotein on the expression of the prorenin receptor in human aortic smooth muscle cells. Mol Med Rep 2015; 11:4341-4. [DOI: 10.3892/mmr.2015.3254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 12/17/2014] [Indexed: 11/06/2022] Open
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Sukhanov S, Snarski P, Vaughn C, Lobelle-Rich P, Kim C, Higashi Y, Shai SY, Delafontaine P. Insulin-like growth factor I reduces lipid oxidation and foam cell formation via downregulation of 12/15-lipoxygenase. Atherosclerosis 2014; 238:313-20. [PMID: 25549319 DOI: 10.1016/j.atherosclerosis.2014.12.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 11/19/2014] [Accepted: 12/14/2014] [Indexed: 01/15/2023]
Abstract
OBJECTIVE We have shown that insulin-like growth factor I (IGF-1) infusion in Apoe(-/-) mice decreased atherosclerotic plaque size and plaque macrophage and lipid content suggesting that IGF-1 suppressed formation of macrophage-derived foam cells. Since 12/15-lipoxygenase (12/15-LOX) plays an important role in OxLDL and foam cell formation, we hypothesized that IGF-1 downregulates 12/15-LOX, thereby suppressing lipid oxidation and foam cell formation. APPROACH AND RESULTS We found that IGF-1 decreased 12/15-LOX plaque immunopositivity and serum OxLDL levels in Apoe(-/-) mice. IGF-1 reduced 12/15-LOX protein and mRNA levels in cultured THP-1 macrophages and IGF-1 also decreased expression of STAT6 transcription factor. IGF-1 reduction in macrophage 12/15-LOX was mediated in part via a PI3 kinase- and STAT6-dependent transcriptional mechanism. IGF-1 suppressed THP-1 macrophage ability to oxidize lipids and form foam cells. IGF-1 downregulated 12/15-LOX in human blood-derived primary macrophages and IGF-1 decreased LDL oxidation induced by these cells. IGF-1 reduced LDL oxidation and formation of foam cells by wild type murine peritoneal macrophages, however these effects were completely blocked in 12/15-LOX-null macrophages suggesting that the ability of IGF-1 to reduce LDL oxidation and foam cells formation is dependent on its ability to downregulate 12/15-LOX. CONCLUSIONS Overall our data demonstrate that IGF-1 reduces lipid oxidation and foam cell formation via downregulation of 12/15-LOX and this mechanism may play a major role in the anti-atherosclerotic effects of IGF-1.
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Affiliation(s)
- Sergiy Sukhanov
- Heart and Vascular Institute, School of Medicine, Tulane University, New Orleans, LA 70112, USA.
| | - Patricia Snarski
- Heart and Vascular Institute, School of Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Charlotte Vaughn
- Heart and Vascular Institute, School of Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Patricia Lobelle-Rich
- Heart and Vascular Institute, School of Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Catherine Kim
- Heart and Vascular Institute, School of Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Yusuke Higashi
- Heart and Vascular Institute, School of Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Shaw-Yung Shai
- Heart and Vascular Institute, School of Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Patrice Delafontaine
- Heart and Vascular Institute, School of Medicine, Tulane University, New Orleans, LA 70112, USA
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11
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Ryu JS, Jung YH, Cho MY, Yeo JE, Choi YJ, Kim YI, Koh YG. Co-culture with human synovium-derived mesenchymal stem cells inhibits inflammatory activity and increases cell proliferation of sodium nitroprusside-stimulated chondrocytes. Biochem Biophys Res Commun 2014; 447:715-20. [DOI: 10.1016/j.bbrc.2014.04.077] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 04/15/2014] [Indexed: 01/15/2023]
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12
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Mechanisms of ascorbyl radical formation in human platelet-rich plasma. BIOMED RESEARCH INTERNATIONAL 2014; 2014:614506. [PMID: 24696859 PMCID: PMC3947840 DOI: 10.1155/2014/614506] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 01/09/2014] [Indexed: 11/21/2022]
Abstract
Recently, many clinical reports have suggested that the ascorbyl free radical (Asc∙) can be treated as a noninvasive, reliable, real-time marker of oxidative stress, but its generation mechanisms in human blood have rarely been discussed. In this study, we used upstream substances, enzyme inhibitors, and free radical scavengers to delineate the mechanisms of Asc∙ formation in human platelet-rich plasma (PRP). Our results show that the doublet signal was detected in PRP samples by using electron spin resonance, and the hyperfine splitting of the doublet signal was aH = 1.88 gauss and g-factor = 2.00627, which was determined to be the Asc∙. We observed that the inhibitors of NADPH oxidase (NOX), cyclooxygenase (COX), lipoxygenase (LOX), cytochrome P450 (CYP450), mitochondria complex III, and nitric oxide synthase (NOS), but not xanthine oxidase, diminished the intensity of the Asc∙ signal dose dependently. All enzyme inhibitors showed no obvious antioxidant activity during a Fenton reaction assay. In summary, the obtained data suggest that Asc∙ formation is associated with NOX, COX, LOX, CYP450, eNOS, and mitochondria in human PRP.
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13
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Higashi Y, Pandey A, Goodwin B, Delafontaine P. Insulin-like growth factor-1 regulates glutathione peroxidase expression and activity in vascular endothelial cells: Implications for atheroprotective actions of insulin-like growth factor-1. Biochim Biophys Acta Mol Basis Dis 2012; 1832:391-9. [PMID: 23261989 DOI: 10.1016/j.bbadis.2012.12.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 11/29/2012] [Accepted: 12/10/2012] [Indexed: 10/27/2022]
Abstract
Oxidative stress promotes endothelial cell senescence and endothelial dysfunction, important early steps in atherogenesis. To investigate potential antioxidant effects of IGF-1 we treated human aortic endothelial cells (hAECs) with 0-100ng/mL IGF-1 prior to exposure to native or oxidized low-density lipoprotein (oxLDL). IGF-1 dose- and time- dependently reduced basal- and oxLDL-induced ROS generation. IGF-1 did not alter superoxide dismutase or catalase activity but markedly increased activity of glutathione peroxidase (GPX), a crucial antioxidant enzyme, via a phosphoinositide-3 kinase dependent pathway. IGF-1 did not increase GPX1 mRNA levels but increased GPX1 protein levels by 2.6-fold at 24h, and altered selenocysteine-incorporation complex formation on GPX1 mRNA. Furthermore, IGF-1 blocked hydrogen peroxide induced premature cell senescence in hAECs. In conclusion, IGF-1 upregulates GPX1 expression in hAECs via a translational mechanism, which may play an important role in the ability of IGF-1 to reduce endothelial cell oxidative stress and premature senescence. Our findings have major implications for understanding vasculoprotective effects of IGF-1.
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Affiliation(s)
- Yusuke Higashi
- Tulane University School of Medicine, New Orleans, LA 70112, USA.
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14
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Shirpoor A, Khadem Ansari MH, Heshmatian B, Ilkhanizadeh B, Noruzi L, Abdollahzadeh N, Saboory E. Decreased blood pressure with a corresponding decrease in adhesive molecules in diabetic rats caused by vitamin E administration. J Diabetes 2012; 4:362-8. [PMID: 22236396 DOI: 10.1111/j.1753-0407.2012.00184.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND Hypertension is one of the important clinical problems of diabetic cardiovascular disease. The aim of this study was to determine the effect of vitamin E on blood pressure parameters and adhesive molecule amounts in diabetic rats. METHODS Twenty-four male Wistar rats were divided into three groups (each of n = 8): the controls (C), non-treated diabetic (NTD), and vitamin E treated diabetic (VETD) groups. A single intraperitoneal injection of buffered streptozotocin (60 mg/kg) in cold sodium citrate (pH 4.5) was used to induce diabetes. The VETD group received 300 mg of vitamin E daily intragastrically for 6 weeks. Systolic and diastolic blood pressure, mean arterial pressure, as well as the dicrotic pressure, crest time, systolic and diastolic periods, and plasma levels of intercellular adhesion molecule-1 and E-selectin were measured after 6 weeks. RESULTS The results revealed that there was a significant increase in systolic and diastolic blood pressures, mean arterial pressure, crest time, systolic duration, and the amount of sICAM-1 and E-selectin in diabetic rats. There was no significant difference in the heart rate or cardiac cyclic duration among the different groups. Significant improvement of blood pressure parameters as well as attenuation of the elevated ICAM-1 and E-selectin amounts was found in the vitamin E treated group. CONCLUSIONS These findings indicate that vitamin E significantly improved blood pressure elevation in diabetic rats and that these effects could be associated with reducing adhesive molecule and antioxidant properties of vitamin E.
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Affiliation(s)
- Alireza Shirpoor
- Department of Physiology, Faculty of Medicine, Urmia Medical University, Urmia, Iran.
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15
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Higashi Y, Sukhanov S, Anwar A, Shai SY, Delafontaine P. Aging, atherosclerosis, and IGF-1. J Gerontol A Biol Sci Med Sci 2012; 67:626-39. [PMID: 22491965 PMCID: PMC3348497 DOI: 10.1093/gerona/gls102] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 03/01/2012] [Indexed: 12/18/2022] Open
Abstract
Insulin-like growth factor 1 (IGF-1) is an endocrine and autocrine/paracrine growth factor that circulates at high levels in the plasma and is expressed in most cell types. IGF-1 has major effects on development, cell growth and differentiation, and tissue repair. Recent evidence indicates that IGF-1 reduces atherosclerosis burden and improves features of atherosclerotic plaque stability in animal models. Potential mechanisms for this atheroprotective effect include IGF-1-induced reduction in oxidative stress, cell apoptosis, proinflammatory signaling, and endothelial dysfunction. Aging is associated with increased vascular oxidative stress and vascular disease, suggesting that IGF-1 may exert salutary effects on vascular aging processes. In this review, we will provide a comprehensive update on IGF-1's ability to modulate vascular oxidative stress and to limit atherogenesis and the vascular complications of aging.
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Affiliation(s)
- Yusuke Higashi
- Tulane University Heart & Vascular Institute, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA
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16
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Itabe H. Oxidized low-density lipoprotein as a biomarker of in vivo oxidative stress: from atherosclerosis to periodontitis. J Clin Biochem Nutr 2012; 51:1-8. [PMID: 22798705 PMCID: PMC3391857 DOI: 10.3164/jcbn.11-00020r1] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 11/28/2011] [Indexed: 12/14/2022] Open
Abstract
Oxidized low-density lipoprotein is known as an important factor in the development of atherosclerosis. The introduction of a sensitive procedure for the determination of oxidized low-density lipoprotein in human circulating plasma using a monoclonal antibody recognizing oxidized phosphatidylcholines has opened new fields of research based on in vivo oxidized low-density lipoprotein. The plasma oxidized low-density lipoprotein levels are significantly elevated in patients with acute myocardial infarction, cerebral infarction or chronic renal failure accompanied by hemodialysis. It was found that the plasma oxidized low-density lipoprotein level increased prior to aortic atherosclerotic lesion enlargement in apolipoprotein E-knockout mice. Recent studies have pointed out that oxidized low-density lipoprotein is transferrable between vessel wall tissue and the circulation, so it is a reasonable hypothesis that plasma oxidized low-density lipoprotein levels reflect the oxidative status at local sites of atherogenesis. Oxidized low-density lipoprotein measurement has been applied to human gingival crevicular fluids, which can be collected easily and safely, and relatively high levels of oxidized low-density lipoprotein were shown to be present. These findings, together with recent clinical follow-up studies, suggest that oxidized low-density lipoprotein is a predictive biomarker of a variety of diseases related to oxidative stress. This review summarizes the current understanding of in vivo oxidized low-density lipoprotein and its potential significance as a biomarker of disease.
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Affiliation(s)
- Hiroyuki Itabe
- Department of Biological Chemistry, Showa University School of Pharmacy, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan
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17
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von der Thüsen JH, Borensztajn KS, Moimas S, van Heiningen S, Teeling P, van Berkel TJC, Biessen EAL. IGF-1 has plaque-stabilizing effects in atherosclerosis by altering vascular smooth muscle cell phenotype. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 178:924-34. [PMID: 21281823 DOI: 10.1016/j.ajpath.2010.10.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2009] [Revised: 09/30/2010] [Accepted: 10/19/2010] [Indexed: 01/17/2023]
Abstract
Insulin-like growth factor-1 (IGF-1) signaling is important for the maintenance of plaque stability in atherosclerosis due to its effects on vascular smooth muscle cell (vSMC) phenotype. To investigate this hypothesis, we studied the effects of the highly inflammatory milieu of the atherosclerotic plaque on IGF-1 signaling and stability-related phenotypic parameters of murine vSMCs in vitro, and the effects of IGF-1 supplementation on plaque phenotype in an atherosclerotic mouse model. M1-polarized, macrophage-conditioned medium inhibited IGF-1 signaling by ablating IGF-1 and increasing IGF-binding protein 3, increased vSMC apoptosis, and decreased proliferation. Expression of α-actin and col3a1 genes was strongly attenuated by macrophage-conditioned medium, whereas expression of matrix-degrading enzymes was increased. Importantly, all of these effects could be corrected by supplementation with IGF-1. In vivo, treatment with the stable IGF-1 analog Long R3 IGF-1 in apolipoprotein E knockout mice reduced stenosis and core size, and doubled cap/core ratio in early atherosclerosis. In advanced plaques, Long R3 IGF-1 increased the vSMC content of the plaque by more than twofold and significantly reduced the rate of intraplaque hemorrhage. We believe that IGF-1 in atherosclerotic plaques may have a role in preventing plaque instability, not only by modulating smooth muscle cell turnover, but also by altering smooth muscle cell phenotype.
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Affiliation(s)
- Jan H von der Thüsen
- Department of Histopathology, Royal Brompton and Harefield NHS Foundation Trust, London, United Kingdom.
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18
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Shai SY, Sukhanov S, Higashi Y, Vaughn C, Rosen CJ, Delafontaine P. Low circulating insulin-like growth factor I increases atherosclerosis in ApoE-deficient mice. Am J Physiol Heart Circ Physiol 2011; 300:H1898-906. [PMID: 21335474 DOI: 10.1152/ajpheart.01081.2010] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Some clinical studies have suggested that lower IGF-I levels may be associated with an increased risk of ischemic heart disease. We generated atherosclerosis-prone apolipoprotein E-deficient (ApoE(-/-)) mice with 6T alleles (6T/ApoE(-/-) mice) with a 20% decline in circulating IGF-I and fed these mice and control ApoE(-/-) mice with normal chow or a Western diet for 12 wk to evaluate the effect of low serum IGF-I on atherosclerosis progression. We found that the 6T/ApoE(-/-) phenotype was characterized by an increased atherosclerotic burden, elevated plaque macrophages, and increased proinflammatory cytokine TNF-α levels compared with ApoE(-/-) controls. 6T/ApoE(-/-) mice had similar body weight, blood pressure, serum total cholesterol levels, total plaque and smooth muscle cell apoptosis rates, and circulating levels of endothelial progenitor cells as ApoE(-/-) mice. 6T/ApoE(-/-) mice fed with normal chow had reduced vascular endothelial nitric oxide synthase mRNA levels and a trend to increased aortic expression of chemokine (C-C motif) receptor (CCR)1, CCR2, and monocyte chemoattractant protein-1/chemokine (C-C motif) ligand 2. Western diet-fed 6T/ApoE(-/-) mice had a trend to increased expression of macrophage scavenger receptor-1/scavenger receptor-A, osteopontin, ATP-binding cassette (subfamily A, member 1), and angiotensin-converting enzyme and elevated circulating levels of the neutrophil chemoattractant chemokine (C-X-C motif) ligand 1 (KC). Our data establish a link between lower circulating IGF-I and increased atherosclerosis that has important clinical implications.
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Affiliation(s)
- Shaw-Yung Shai
- Tulane University Heart and Vascular Institute, Tulane University School of Medicine, New Orleans, Louisisana, USA
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19
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Higashi Y, Holder K, Delafontaine P. Thiazolidinediones up-regulate insulin-like growth factor-1 receptor via a peroxisome proliferator-activated receptor gamma-independent pathway. J Biol Chem 2010; 285:36361-8. [PMID: 20843793 PMCID: PMC2978564 DOI: 10.1074/jbc.m110.137661] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 09/01/2010] [Indexed: 11/06/2022] Open
Abstract
There is increasing evidence that thiazolidinediones (TZDs), antidiabetic compounds that are synthetic ligands for the peroxisome proliferator-activated receptor γ (PPARγ), have cardiovascular effects through as yet poorly defined mechanisms. We tested the effect of two TZD class drugs, rosiglitazone and pioglitazone, on human aortic smooth muscle cell (SMC) expression of insulin-like growth factor-1 receptor (IGF-1R). Both TZDs dose dependently up-regulated IGF-1R protein levels (rosiglitazone, 10 μmol/liter, 67% increase, n = 4, p < 0.01; pioglitazone, 10 μmol/liter, 41% increase, n = 4, p < 0.01) and increased IGF-1R signaling activity (36% increase in Akt phosphorylation). However, the endogenous PPARγ ligand, 15-deoxy-Δ(12,14)-prostaglandin J(2), dose dependently reduced IGF-1R (10 μmol/liter, 80% decrease, n = 4, p < 0.01), and overexpression of PPARγ using an adenovirus likewise reduced IGF-1R (50% decrease versus SMC infected with control adenovirus), suggesting a PPARγ-independent action of TZDs. All three PPARγ ligands (rosiglitazone, pioglitazone, and 15-deoxy-Δ(12,14)-prostaglandin J(2)), however, did not change IGF-1R mRNA levels, indicating that their effects were posttranscriptional. Use of bicistronic constructs revealed that TZD induction of IGF-1R translation occurred via internal ribosomal entry. To examine the potential physiological relevance of TZD up-regulation of IGF-1R, we determined the effect of rosiglitazone on oxidized LDL (oxLDL)-induced apoptosis. 20 μmol/liter of rosiglitazone reduced oxidized LDL-induced apoptosis by 40% and neutralizing antibody to IGF-1R (αIR3) counteracted this rescue, suggesting the rosiglitazone survival effect was, at least in part, mediated by IGF-1R. In conclusion, TZDs markedly up-regulate SMC IGF-1R expression and signaling, likely via a PPARγ-independent mechanism. This novel action of TZDs may play an important role in their cardiovascular effects.
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MESH Headings
- Aorta/cytology
- Aorta/drug effects
- Aorta/metabolism
- Blotting, Western
- Cells, Cultured
- Humans
- Hypoglycemic Agents/pharmacology
- Lipoproteins, LDL/genetics
- Lipoproteins, LDL/metabolism
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- PPAR gamma/genetics
- PPAR gamma/metabolism
- Phosphorylation
- RNA, Messenger/genetics
- Receptor, IGF Type 1/genetics
- Receptor, IGF Type 1/metabolism
- Receptor, Insulin/genetics
- Receptor, Insulin/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Rosiglitazone
- Signal Transduction/drug effects
- Thiazolidinediones/pharmacology
- Up-Regulation
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Affiliation(s)
- Yusuke Higashi
- From the Tulane University Heart & Vascular Institute, Tulane University School of Medicine, New Orleans, Louisiana 70112
| | - Kevin Holder
- From the Tulane University Heart & Vascular Institute, Tulane University School of Medicine, New Orleans, Louisiana 70112
| | - Patrice Delafontaine
- From the Tulane University Heart & Vascular Institute, Tulane University School of Medicine, New Orleans, Louisiana 70112
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20
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Shai SY, Sukhanov S, Higashi Y, Vaughn C, Kelly J, Delafontaine P. Smooth muscle cell-specific insulin-like growth factor-1 overexpression in Apoe-/- mice does not alter atherosclerotic plaque burden but increases features of plaque stability. Arterioscler Thromb Vasc Biol 2010; 30:1916-24. [PMID: 20671230 DOI: 10.1161/atvbaha.110.210831] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Growth factors may play a permissive role in atherosclerosis initiation and progression, in part via their promotion of vascular smooth muscle cell (VSMC) accumulation in plaques. However, unstable human plaques often have a relative paucity of VSMC, which has been suggested to contribute to plaque rupture and erosion and to clinical events. Insulin-like growth factor-1 (IGF-1) is an endocrine and autocrine/paracrine growth factor that is a mitogen for VSMC, but when infused into Apoe(-/-) mice it paradoxically reduces atherosclerosis burden. METHODS AND RESULTS To determine the effect of stimulation of VSMC growth on atherosclerotic plaque development and to understand mechanisms of IGF-1's atheroprotective effect, we assessed atherosclerotic plaques in mice overexpressing IGF-1 in smooth muscle cells (SMC) under the control of the α-smooth muscle actin promoter, after backcrossing to the Apoe(-/-) background (SMP8/Apoe(-/-)). Compared with Apoe(-/-) mice, these SMP8/Apoe(-/-) mice developed a comparable plaque burden after 12 weeks on a Western diet, suggesting that the ability of increased circulating IGF-1 to reduce plaque burden was mediated in large part via non-SMC target cells. However, advanced plaques in SMP8/Apoe(-/-) mice displayed several features of plaque stability, including increased fibrous cap area, α-smooth muscle actin-positive SMC and collagen content, and reduced necrotic cores. CONCLUSIONS These findings indicate that stimulation of VSMC IGF-1 signaling does not alter total atherosclerotic plaque burden and may improve atherosclerotic plaque stability.
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Affiliation(s)
- Shaw-Yung Shai
- Tulane University Heart and Vascular Institute, Tulane University School of Medicine, New Orleans, La 70112, USA
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21
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Yu XY, Geng YJ, Liang JL, Lin QX, Lin SG, Zhang S, Li Y. High levels of glucose induce apoptosis in cardiomyocyte via epigenetic regulation of the insulin-like growth factor receptor. Exp Cell Res 2010; 316:2903-9. [PMID: 20633551 DOI: 10.1016/j.yexcr.2010.07.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Revised: 07/02/2010] [Accepted: 07/06/2010] [Indexed: 12/28/2022]
Abstract
Diabetic hyperglycemia result in cardiovascular complications, but the mechanisms by which high levels of glucose (HG) cause diabetic cardiomyopathy are not known. We investigate whether HG-induced repression of insulin-like growth factor 1 receptor (IGF-1R) mediated by epigenetic modifications is one potential mechanism. We found that HG resulted in decreased IGF-1 receptor (IGF-1R) mRNA levels, and IGF-1R protein when compared with H9C2 rat cardiomyocyte cells incubated in normal glucose. HG also induced apoptosis of H9C2 cells. The effects of HG on reduced expression of IGF-1R and increased apoptosis were blocked by silencing p53 with small interference RNA but not by non-targeting scrambled siRNA. Moreover, HG negatively regulated IGF-1R promoter activity as determined by ChIP analysis, which was dependent on p53 since siRNA-p53 attenuated the effects of HG on IGF-1R promoter activity. HG also increased the association of p53 with histone deacetylase 1 (HDAC1), and decreased the association of acetylated histone-4 with the IGF-1R promoter. Furthermore, HDAC inhibitor relieved the repression of IGF-1R following HG state. These results suggest that HG-induced repression of IGF-1R is mediated by the association of p53 with the IGF-1R promoter, and by the subsequent enhanced recruitment of chromatin-modifying proteins, such as HDAC1, to the IGF-1R promoter-p53 complex. In conclusion, our data demonstrate that HG decreases expression of IGF-1R and decreases the association of acetylated histone-4 with the IGF-1R promoter. These studies may help delineate the complex pathways regulating diabetic cardiomyopathy, and have implications for the development of novel therapeutic strategies to prevent diabetic cardiomyopathy by epigenetic regulation of IGF-1R.
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Affiliation(s)
- Xi-Yong Yu
- Medical Research Center, Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, P.R. China.
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22
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Levitan I, Volkov S, Subbaiah PV. Oxidized LDL: diversity, patterns of recognition, and pathophysiology. Antioxid Redox Signal 2010; 13:39-75. [PMID: 19888833 PMCID: PMC2877120 DOI: 10.1089/ars.2009.2733] [Citation(s) in RCA: 311] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2009] [Revised: 10/09/2009] [Accepted: 11/02/2009] [Indexed: 02/06/2023]
Abstract
Oxidative modification of LDL is known to elicit an array of pro-atherogenic responses, but it is generally underappreciated that oxidized LDL (OxLDL) exists in multiple forms, characterized by different degrees of oxidation and different mixtures of bioactive components. The variable effects of OxLDL reported in the literature can be attributed in large part to the heterogeneous nature of the preparations employed. In this review, we first describe the various subclasses and molecular composition of OxLDL, including the variety of minimally modified LDL preparations. We then describe multiple receptors that recognize various species of OxLDL and discuss the mechanisms responsible for the recognition by specific receptors. Furthermore, we discuss the contentious issues such as the nature of OxLDL in vivo and the physiological oxidizing agents, whether oxidation of LDL is a prerequisite for atherogenesis, whether OxLDL is the major source of lipids in foam cells, whether in some cases it actually induces cholesterol depletion, and finally the Janus-like nature of OxLDL in having both pro- and anti-inflammatory effects. Lastly, we extend our review to discuss the role of LDL oxidation in diseases other than atherosclerosis, including diabetes mellitus, and several autoimmune diseases, such as lupus erythematosus, anti-phospholipid syndrome, and rheumatoid arthritis.
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Affiliation(s)
- Irena Levitan
- Section of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
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23
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Higashi Y, Sukhanov S, Anwar A, Shai SY, Delafontaine P. IGF-1, oxidative stress and atheroprotection. Trends Endocrinol Metab 2010; 21:245-54. [PMID: 20071192 PMCID: PMC2848911 DOI: 10.1016/j.tem.2009.12.005] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Revised: 12/10/2009] [Accepted: 12/11/2009] [Indexed: 01/30/2023]
Abstract
Atherosclerosis is a chronic inflammatory disease in which early endothelial dysfunction and subintimal modified lipoprotein deposition progress to complex, advanced lesions that are predisposed to erosion, rupture and thrombosis. Oxidative stress plays a crucial role not only in initial lesion formation but also in lesion progression and destabilization. Although most growth factors are thought to promote vascular smooth muscle cell proliferation and migration, thereby increasing neointima, recent animal studies indicate that insulin-like growth factor (IGF)-1 exerts both pleiotropic anti-oxidant effects and anti-inflammatory effects, which together reduce atherosclerotic burden. This review discusses the effects of IGF-1 in models of vascular injury and atherosclerosis, emphasizing the relationship between oxidative stress and potential atheroprotective actions of IGF-1.
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Affiliation(s)
- Yusuke Higashi
- Tulane University School of Medicine, 1430 Tulane Avenue, SL 48, New Orleans, LA 70112, USA
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24
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Titterington JS, Sukhanov S, Higashi Y, Vaughn C, Bowers C, Delafontaine P. Growth hormone-releasing peptide-2 suppresses vascular oxidative stress in ApoE-/- mice but does not reduce atherosclerosis. Endocrinology 2009; 150:5478-87. [PMID: 19819949 PMCID: PMC2795722 DOI: 10.1210/en.2009-0283] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
GH-releasing peptide-2 (GHRP-2) is a synthetic peptide that increases circulating GH and IGF-I levels. It also binds to CD36, a scavenger receptor for oxidized low-density lipoprotein (OxLDL), and may prevent cellular uptake of this proatherogenic complex. To determine its potential antiatherogenic effects, GHRP-2 (20 microg twice daily) was administered sc to ApoE(-/-) mice for 12 wk. GHRP-2 increased circulating IGF-I 1.2- to 1.6-fold and decreased circulating interferon-gamma by 66%. Although GHRP-2 did not alter atherosclerotic plaque area, it decreased aortic production of superoxide as assessed by dihydroethidium staining. GHRP-2 decreased aortic gene expression of 12/15-lipoxygenase by 92% and reduced the aortic expression of interferon-gamma and macrophage migration inhibitory factor. In cultured aortic smooth muscle cells, GHRP-2 prevented the OxLDL-induced generation of peroxides, down-regulation of IGF-I receptor, and apoptosis. In macrophages, GHRP-2 reduced lipid accumulation with OxLDL exposure. In summary, GHRP-2 exerts antioxidant effects in vivo and in vitro but does not reduce plaque burden. The lack of an antiatherogenic effect may be due to GH-dependent effects in vivo, thereby blunting the effect of increased IGF-I.
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Affiliation(s)
- Jane S Titterington
- Section of Endocrinology, Tulane University Heart and Vascular Institute, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA
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Vincent AM, Hinder LM, Pop-Busui R, Feldman EL. Hyperlipidemia: a new therapeutic target for diabetic neuropathy. J Peripher Nerv Syst 2009; 14:257-67. [PMID: 20021567 PMCID: PMC4239691 DOI: 10.1111/j.1529-8027.2009.00237.x] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Emerging data establish dyslipidemia as a significant contributor to the development of diabetic neuropathy. In this review, we discuss how separate metabolic imbalances, including hyperglycemia and hyperlipidemia, converge on mechanisms leading to oxidative stress in dorsal root ganglia (DRG) sensory neurons. We conclude with suggestions for novel therapeutic strategies to prevent or reverse diabetes-induced nerve degeneration.
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Affiliation(s)
- Andrea M Vincent
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA.
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26
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Allen LB, Capps BE, Miller EC, Clemmons DR, Maile LA. Glucose-oxidized low-density lipoproteins enhance insulin-like growth factor I-stimulated smooth muscle cell proliferation by inhibiting integrin-associated protein cleavage. Endocrinology 2009; 150:1321-9. [PMID: 18974270 PMCID: PMC5393262 DOI: 10.1210/en.2008-1090] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Prior published reports have demonstrated that glucose-oxidized low-density lipoproteins (g-OxLDL) enhance the proliferative response of vascular smooth muscle cells (SMC) to IGF-I. Our previous studies have determined that the regulation of cleavage of integrin-associated protein (IAP) by matrix-metalloprotease-2 (MMP-2) in diabetic mice in response to hyperglycemia is a key regulator of the response of SMC to IGF-I. Because chronic hyperglycemia enhances glucose-induced LDL oxidation, these studies were conducted to determine whether g-OxLDL modulates the response of SMC to IGF-I by regulating MMP-2-mediated cleavage of IAP. We determined that exposure of SMC to g-OxLDL, but not native LDL, was sufficient to facilitate an increase in cell proliferation in response to IGF-I. Exposure to an anti-CD36 antibody, which has been shown to inhibit g-OxLDL-mediated signaling, inhibited the effects of g-OxLDL on IGF-I-stimulated SMC proliferation. The effect of g-OxLDL could be attributed, in part, to an associated decrease in proteolytic cleavage of IAP leading to increase in the basal association between IAP and Src homology 2 domain-containing protein tyrosine phosphatase substrate-1, which is required for IGF-I-stimulated proliferation. The inhibitory effect of g-OxLDL on IAP cleavage appeared to be due to its ability to decrease the amount of activated MMP-2, the protease responsible for IAP cleavage. In conclusion, these data provide a molecular mechanism to explain previous studies that have reported an enhancing effect of g-OxLDL on IGF-I-stimulated SMC proliferation.
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Affiliation(s)
- Lee B Allen
- Department of Medicine, Division of Endocrinology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7170, USA
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27
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Insulin-Like Growth Factors, Cardiovascular Risk Factors, and Cardiovascular Disease. Cardiovasc Endocrinol 2008. [DOI: 10.1007/978-1-59745-141-3_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Higashi Y, Sukhanov S, Parthasarathy S, Delafontaine P. The ubiquitin ligase Nedd4 mediates oxidized low-density lipoprotein-induced downregulation of insulin-like growth factor-1 receptor. Am J Physiol Heart Circ Physiol 2008; 295:H1684-9. [PMID: 18723765 DOI: 10.1152/ajpheart.00548.2008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Oxidized low-density lipoprotein (LDL) is proatherogenic and induces smooth muscle cell apoptosis, which contributes to atherosclerotic plaque destabilization. We showed previously that oxidized LDL downregulates insulin-like growth factor-1 receptor in human smooth muscle cells and that this is critical for induction of apoptosis. To identify mechanisms, we exposed smooth muscle cells to 60 mug/ml oxidized LDL or native LDL and assessed insulin-like growth factor-1 receptor mRNA levels, protein synthesis rate, and receptor protein stability. Oxidized LDL decreased insulin-like growth factor-1 receptor mRNA levels by 30% at 8 h compared with native LDL, and this decrease was maintained for up to 20 h. However, insulin-like growth factor-1 receptor protein synthesis rate was not altered by oxidized LDL. Pulse-chase labeling experiments revealed that oxidized LDL reduced insulin-like growth factor-1 receptor protein half-life to 12.2+/-1.7 h from 24.4+/-4.7 h with native LDL. This destabilization of insulin-like growth factor-1 receptor protein was accompanied by enhanced receptor ubiquitination. Overexpression of dominant-negative Nedd4 prevented oxidized LDL-induced downregulation of insulin-like growth factor-1 receptor, suggesting that Nedd4 was the ubiquitin ligase that mediated receptor downregulation. However, the proteasome inhibitors lactacystin, MG-132, and proteasome inhibitor-1 failed to block oxidized LDL-induced downregulation of insulin-like growth factor-1 receptor. Thus oxidized LDL downregulates insulin-like growth factor-1 receptor by destabilizing the protein via Nedd4-enhanced ubiquitination, leading to degradation via a proteasome-independent pathway. This finding provides novel insights into oxidized LDL-triggered oxidant signaling and mechanisms of smooth muscle cell depletion that contribute to plaque destabilization and coronary events.
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Affiliation(s)
- Yusuke Higashi
- Section of Cardiology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA
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Choi JS, Choi YJ, Shin SY, Li J, Kang SW, Bae JY, Kim DS, Ji GE, Kang JS, Kang YH. Dietary flavonoids differentially reduce oxidized LDL-induced apoptosis in human endothelial cells: role of MAPK- and JAK/STAT-signaling. J Nutr 2008; 138:983-90. [PMID: 18492823 DOI: 10.1093/jn/138.6.983] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Endothelial apoptosis is a driving force in atherosclerosis development. Oxidized LDL promotes inflammatory and thrombotic processes and is highly atherogenic, as it stimulates macrophage cholesterol accumulation and foam cell formation. This study investigated multiple mitogen-activated protein kinase (MAPK)-responsive death/survival signaling pathways, through which flavonoids of (-)epigallocatechin gallate (EGCG) and hesperetin exerted antiapoptosis in endothelial cells exposed to oxidized LDL. EGCG and hesperetin substantially diminished the oxidized LDL-induced 2',7'-dichlorofluorecein staining, suggesting that these flavonoids inhibited intracellular accumulation of oxidized LDL-triggered reactive oxygen species and consequent apoptosis. The Western-blot data revealed that oxidized LDL upregulated c-Jun N-terminal kinase (JNK) phosphorylation, which was rapidly reversed by EGCG and hesperetin. They mitigated the consequent activation of the JNK downstream on p53 and c-Jun. Moreover, oxidized LDL increased luciferase activity of p53 in endothelial cells transfected with a p53 promoter construct, the increase of which was strikingly downregulated by EGCG and hesperetin. Surprisingly, hesperetin but not EGCG attenuated phosphorylation of p38MAPK and its downstream c-myc and signal transducers and activators of transcription (STAT)1 evoked by oxidized LDL. This study also attempted to explore a linkage of Janus kinase (JAK)2/STAT3 activation to MAPK signaling in oxidized LDL-induced endothelial apoptosis. Notably, we found that the JAK2 inhibitor substantially blocked the JNK activation. Our findings suggest that EGCG and hesperetin may act as antiatherogenic agents blocking oxidized LDL-induced endothelial apoptosis via differential cellular apoptotic machinery. These data provide evidence that the interplay between p38MAPK and JAK-STAT pathways is involved in dietary flavonoid protection against oxidized LDL through hampering MAPK-dependent pathways involving the activation of JAK2.
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Affiliation(s)
- Jung-Suk Choi
- Department of Food and Nutrition, Hallym University, Chuncheon, Korea
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Conover CA, Harrington SC, Bale LK. Differential regulation of pregnancy associated plasma protein-A in human coronary artery endothelial cells and smooth muscle cells. Growth Horm IGF Res 2008; 18:213-220. [PMID: 17936662 PMCID: PMC2396756 DOI: 10.1016/j.ghir.2007.09.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Revised: 07/30/2007] [Accepted: 09/04/2007] [Indexed: 10/22/2022]
Abstract
BACKGROUND Pregnancy-associated plasma protein-A (PAPP-A), a metalloproteinase that serves to modulate local insulin-like growth factor (IGF) action, is upregulated in atherosclerotic plaque. However, little is known about the cellular mechanisms underlying this elevated PAPP-A. OBJECTIVE To continue study of PAPP-A expression and its regulation in human vascular cells, with a focus on endothelial cells. DESIGN Primary cultures of human coronary artery endothelial cells (ECs) were treated without and with cytokines, growth factors, or low density lipoprotein (LDL). PAPP-A mRNA, protein, and protease activity were assessed using real-time PCR, ultra-sensitive PAPP-A ELISA and cell-free proteolysis of IGF binding protein (IGFBP-4), respectively. In addition, vascular cell adhesion molecule (VCAM), intercellular adhesion molecule (ICAM), monocyte chemotactic protein (MCP-1), IGF-I, IGF-I receptor, and IGFBP-4 and -5 mRNA expression levels were determined. RESULTS ECs in culture show little basal PAPP-A expression. The pro-inflammatory cytokines, tumor necrosis factor (TNF)-alpha and interleukin (IL)-beta, stimulated PAPP-A expression (TNF-alpha>>IL-1beta), whereas there was no effect of IL-6, transforming growth factor-beta, IGF-I, insulin, fibroblast growth factor or epidermal growth factor in these cells. Stimulation of PAPP-A expression by TNF-alpha was associated with significantly increased VCAM, ICAM, and MCP-1 expression but without major changes in other IGF system components. TNF-alpha-induced VCAM, ICAM, and MCP-1 expression (4h) preceded PAPP-A expression (24h). The anti-oxidant, N-acetyl cysteine, inhibited TNF-alpha-induced PAPP-A expression without altering the induction in VCAM, ICAM, and MCP-1. Treatment with native or oxidized LDL had no effect on PAPP-A expression in ECs. Comparative results in human coronary smooth muscle cells indicated qualitative and quantitative differences in PAPP-A expression and regulation between the two vascular cell types. CONCLUSIONS Human coronary artery ECs express PAPP-A mRNA and functional protein when activated by the pro-inflammatory cytokine, TNF-alpha. This study complements work on PAPP-A expression in human coronary artery SMCs and human monocyte-derived macrophages and suggests an interactive model of PAPP-A regulation and action in human atherosclerotic plaque.
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Affiliation(s)
- Cheryl A Conover
- Endocrine Research Unit, Department of Medicine, Mayo Clinic, College of Medicine, 200 First Street SW, 5-194 Joseph, Rochester, MN 55905, United States.
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Debacq-Chainiaux F, Pascal T, Boilan E, Bastin C, Bauwens E, Toussaint O. Screening of senescence-associated genes with specific DNA array reveals the role of IGFBP-3 in premature senescence of human diploid fibroblasts. Free Radic Biol Med 2008; 44:1817-32. [PMID: 18329388 DOI: 10.1016/j.freeradbiomed.2008.02.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Revised: 12/29/2007] [Accepted: 02/05/2008] [Indexed: 02/05/2023]
Abstract
Repeated exposures to sublethal concentrations of tert-butylhydroperoxide and ethanol trigger premature senescence of WI-38 human diploid fibroblasts. We found 16 replicative senescence-related genes with similar alterations in expression level in replicative senescence and two models of stress-induced premature senescence. Among these genes was IGFBP-3. Using a siRNA approach, we showed that IGFBP-3 regulates the appearance of several biomarkers of senescence after repeated exposures of WI-38 fibroblasts to tert-butylhydroperoxide and ethanol.
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Affiliation(s)
- Florence Debacq-Chainiaux
- Unit of Research on Cellular Biology, Department of Biology, University of Namur, Rue de Bruxelles, B-5000 Namur, Belgium
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Allard D, Figg N, Bennett MR, Littlewood TD. Akt regulates the survival of vascular smooth muscle cells via inhibition of FoxO3a and GSK3. J Biol Chem 2008; 283:19739-47. [PMID: 18458087 DOI: 10.1074/jbc.m710098200] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Apoptosis of vascular smooth muscle cells (VSMCs) may lead to atherosclerotic plaque instability and rupture, resulting in myocardial infarction, stroke, and sudden death. However, the molecular mechanisms mediating survival of VSMCs in atherosclerotic plaques remain unknown. Although plaque VSMCs exhibit increased susceptibility to apoptosis and reduced expression of the IGF1 receptor (IGF1R) when compared with normal VSMCs, a causative effect has not been established. Here we show that increased expression of the IGF1R can rescue plaque VSMCs from oxidative stress-induced apoptosis, demonstrating that IGF-1 signaling is a critical regulator of VSMC survival. Akt mediates the majority of the IGF1R survival signaling, and ectopic activation of Akt was sufficient to protect VSMCs in vitro. Both IGF1R and phospho-Akt expression were reduced in human plaque (intimal) VSMCs when compared with medial VSMCs, suggesting that Akt mediates survival signaling in atherosclerosis. Importantly, downstream targets of Akt were identified that mediate its protective effect as inhibition of FoxO3a or GSK3 by Akt-dependent phosphorylation protected VSMCs in vitro. We conclude that Akt and its downstream targets FoxO3a and GSK3 regulate a survival pathway in VSMCs and that their deregulation due to a reduction of IGF1R signaling may promote apoptosis in atherosclerosis.
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Affiliation(s)
- David Allard
- Division of Cardiovascular Medicine, University of Cambridge, Box 110, Addenbrooke's Hospital, Cambridge CB2 2QQ, United Kingdom
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Arachidonic Acid metabolites in the cardiovascular system: the role of lipoxygenase isoforms in atherogenesis with particular emphasis on vascular remodeling. J Cardiovasc Pharmacol 2008; 50:609-20. [PMID: 18091576 DOI: 10.1097/fjc.0b013e318159f177] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Vascular remodeling refers to lasting structural alterations in the vessel wall that are initiated in response to external and internal stimuli. These changes are distinct from acute functional responses of blood vessels when challenged by increased blood pressure, altered hemodynamics, or vasoactive mediators. In early atherogenesis, when lesion formation is starting to impact local hemodynamics, the vessel wall responds with outward vascular remodeling to maintain normal blood flow. However, inward remodeling may also occur during the time course of plaque formation, contributing to vascular stenosis. Lipoxygenases form a heterogeneous family of lipid-peroxidizing enzymes, which have been implicated in atherogenesis. Several lines of in vitro and in vivo evidence indicated their involvement in disease development, but the precise function of different lipoxygenase isoforms is still a matter of discussion. Vascular remodeling is an early response during plaque development; therefore, lipoxygenases may be involved in this process. Unfortunately, little is known about the potential role of lipoxygenase isoforms in vascular remodeling. This review will briefly summarize our knowledge of the role of lipoxygenases in vascular biology and will critically review the activities of the 3 most athero-relevant lipoxygenase isoforms in atherogenesis, with particular emphasis on vascular remodeling.
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Sen CK, Roy S. Redox signals in wound healing. Biochim Biophys Acta Gen Subj 2008; 1780:1348-61. [PMID: 18249195 DOI: 10.1016/j.bbagen.2008.01.006] [Citation(s) in RCA: 212] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 12/31/2007] [Accepted: 01/14/2008] [Indexed: 12/19/2022]
Abstract
Physical trauma represents one of the most primitive challenges that threatened survival. Healing a problem wound requires a multi-faceted comprehensive approach. First and foremost, the wound environment will have to be made receptive to therapies. Second, the appropriate therapeutic regimen needs to be identified and provided while managing systemic limitations that could secondarily limit the healing response. Unfortunately, most current solutions seem to aim at designing therapeutic regimen with little or no consideration of the specific details of the wound environment and systemic limitations. One factor that is centrally important in making the wound environment receptive is correction of wound hypoxia. Recent work have identified that oxygen is not only required to disinfect wounds and fuel healing but that oxygen-dependent redox-sensitive signaling processes represent an integral component of the healing cascade. Over a decade ago, it was proposed that in biological systems oxidants are not necessarily always the triggers for oxidative damage and that oxidants such as H2O2 could actually serve as signaling messengers and drive several aspects of cellular signaling. Today, that concept is much more developed and mature. Evidence supporting the role of oxidants such as H2O2 as signaling messenger is compelling. A complete understanding of the continuum between the classical and emergent roles of oxygen requires a thorough consideration of current concepts in redox biology. The objective of this review is to describe our current understanding of how redox-sensitive processes may drive dermal tissue repair.
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Affiliation(s)
- Chandan K Sen
- Comprehensive Wound Center, Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University Medical Center, Columbus, Ohio 43210, USA.
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Knuckles TL, Dreher KL. Fine oil combustion particle bioavailable constituents induce molecular profiles of oxidative stress, altered function, and cellular injury in cardiomyocytes. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2007; 70:1824-1837. [PMID: 17934955 DOI: 10.1080/15287390701459213] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Epidemiological studies have shown a positive association between exposure to air particulate matter (PM) pollution and adverse cardiovascular health effects in susceptible subpopulations such as those with pre-existing cardiovascular disease. The mechanism(s) through which pulmonary deposited PM, particularly fine PM2.5, PM with mass median aerodynamic diameter <2.5 microm, affects the cardiovascular system is currently not known and remains a major focus of investigation. In the present study, the transcriptosome and transcription factor proteome were examined in rat neonatal cardiomyocyte (RCM) cultures, following an acute exposure to bioavailable constituents of PM2.5 oil combustion particles designated residual oil fly ash leachate (ROFA-L). Out of 3924 genes examined, 38 genes were suppressed and 44 genes were induced following a 1-h exposure to 3.5 microg/ml of a particle-free leachate of ROFA (ROFA-L). Genomic alterations in pathways related to IGF-1, VEGF, IL-2, PI3/AKT, cardiovascular disease, and free radical scavenging, among others, were detected 1 h postexposure to ROFA-L. Global gene expression was altered in a manner consistent with cardiac myocyte electrophysiological remodeling, cellular oxidative stress, and apoptosis. ROFA-L altered the transcription factor proteome by suppressing activity of 24 and activating 40 transcription factors out of a total of 149. Genomic alterations were found to correlate with changes in transcription factor proteome. These acute changes indicate pathological molecular alterations, which may lead to possible chronic alterations to the cardiac myocyte. These data also potentially relate underlying cardiovascular effects from occupational exposure to ROFA and identify how particles from specific emission sources may mediate ambient PM cardiac effects.
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Affiliation(s)
- Travis L Knuckles
- North Carolina State University, College of Veterinary Medicine, Raleigh, North Carolina, USA
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Comparison of glucosamine sulfate and a polyherbal supplement for the relief of osteoarthritis of the knee: a randomized controlled trial [ISRCTN25438351]. Altern Ther Health Med 2007; 7:34. [PMID: 17974032 PMCID: PMC2131759 DOI: 10.1186/1472-6882-7-34] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Accepted: 10/31/2007] [Indexed: 11/20/2022]
Abstract
Background The efficacy and safety of a dietary supplement derived from South American botanicals was compared to glucosamine sulfate in osteoarthritis subjects in a Mumbai-based multi-center, randomized, double-blind study. Methods Subjects (n = 95) were screened and randomized to receive glucosamine sulfate (n = 47, 1500 mg/day) or reparagen (n = 48, 1800 mg/day), a polyherbal consisting of 300 mg of vincaria (Uncaria guianensis) and 1500 mg of RNI 249 (Lepidium meyenii) administered orally, twice daily. Primary efficacy variable was response rate based on a 20% improvement in WOMAC pain scores. Additional outcomes were WOMAC scores for pain, stiffness and function, visual analog score (VAS) for pain, with assessments at 1, 2, 4, 6 and 8 weeks. Tolerability, investigator and subject global assessments and rescue medication consumption (paracetamol) were measured together with safety assessments including vital signs and laboratory based assays. Results Subject randomization was effective: age, gender and disease status distribution was similar in both groups. The response rates (20% reduction in WOMAC pain) were substantial for both glucosamine (89%) and reparagen (94%) and supported by investigator and subject assessments. Using related criteria response rates to reparagen were favorable when compared to glucosamine. Compared to baseline both treatments showed significant benefits in WOMAC and VAS outcomes within one week (P < 0.05), with a similar, progressive improvement over the course of the 8 week treatment protocol (45–62% reduction in WOMAC or VAS scores). Tolerability was excellent, no serious adverse events were noted and safety parameters were unchanged. Rescue medication use was significantly lower in the reparagen group (p < 0.01) at each assessment period. Serum IGF-1 levels were unaltered by treatments. Conclusion Both reparagen and glucosamine sulfate produced substantial improvements in pain, stiffness and function in subjects with osteoarthritis. Response rates were high and the safety profile was excellent, with significantly less rescue medication use with reparagen. Reparagen represents a new natural productive alternative in the management of joint health. Trial registration Current Controlled Trials ISRCTN25438351.
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Sukhanov S, Higashi Y, Shai SY, Vaughn C, Mohler J, Li Y, Song YH, Titterington J, Delafontaine P. IGF-1 reduces inflammatory responses, suppresses oxidative stress, and decreases atherosclerosis progression in ApoE-deficient mice. Arterioscler Thromb Vasc Biol 2007; 27:2684-90. [PMID: 17916769 DOI: 10.1161/atvbaha.107.156257] [Citation(s) in RCA: 200] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Whereas growth factors, via their ability to stimulate vascular smooth muscle cell (VSMC) proliferation and migration, have been thought to play a permissive role in atherosclerosis initiation and progression, the role of insulin-like growth factor-1 (IGF-1) is unknown. Here we report for the first time that IGF-1 infusion decreased atherosclerotic plaque progression in ApoE-deficient mice on a Western diet. METHODS AND RESULTS ApoE-null mice (8 weeks) were infused with vehicle or recombinant human IGF-1 and fed a high-fat diet for 12 weeks. Analysis of aortic sinuses revealed that IGF-1 infusion decreased atherosclerotic plaque progression and macrophage infiltration into lesions. Furthermore, IGF-1 decreased vascular expression of the proinflammatory cytokines interleukin-6 and tumor necrosis factor-alpha, reduced aortic superoxide formation and urinary 8-isoprostane levels, and increased aortic pAkt and eNOS expression and circulating endothelial progenitor cells, consistent with an antiinflammatory, antioxidant, and prorepair effect on the vasculature. CONCLUSIONS Our data indicate that an increase in circulating IGF-1 reduces vascular inflammatory responses, systemic and vascular oxidant stress and decreases atherosclerotic plaque progression. These findings have major implications for the treatment of atherosclerosis.
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Affiliation(s)
- Sergiy Sukhanov
- Cardiology Section, Department of Medicine, Tulane University School of Medicine, 1430 Tulane Ave, SL-48, New Orleans, LA 70112, USA
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Kavurma M, Figg N, Bennett M, Mercer J, Khachigian L, Littlewood T. Oxidative stress regulates IGF1R expression in vascular smooth-muscle cells via p53 and HDAC recruitment. Biochem J 2007; 407:79-87. [PMID: 17600529 PMCID: PMC2267398 DOI: 10.1042/bj20070380] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Apoptosis of VSMCs (vascular smooth-muscle cells) leads to features of atherosclerotic plaque instability. We have demonstrated previously that plaque-derived VSMCs have reduced IGF1 (insulin-like growth factor 1) signalling, resulting from a decrease in the expression of IGF1R (IGF1 receptor) compared with normal aortic VSMCs [Patel, Zhang, Siddle, Soos, Goddard, Weissberg and Bennett (2001) Circ. Res. 88, 895-902]. In the present study, we show that apoptosis induced by oxidative stress is inhibited by ectopic expression of IGF1R. Oxidative stress repressed IGF1R expression at multiple levels, and this was also blocked by mutant p53. Oxidative stress also induced p53 phosphorylation and apoptosis in VSMCs. p53 negatively regulated IGF1R promoter activity and expression and, consistent with this, p53-/- VSMCs demonstrated increased IGF1R expression, both in vitro and in advanced atherosclerotic plaques in vivo. Oxidative-stress-induced interaction of endogenous p53 with TBP (TATA-box-binding protein) was dependent on p53 phosphorylation. Oxidative stress also increased the association of p53 with HDAC1 (histone deacetylase 1). Trichostatin A, a specific HDAC inhibitor, or p300 overexpression relieved the repression of IGF1R following oxidative stress. Furthermore, acetylated histone-4 association with the IGF1R promoter was reduced in cells subjected to oxidative stress. These results suggest that oxidative-stress-induced repression of IGF1R is mediated by the association of phosphorylated p53 with the IGF1R promoter via TBP, and by the subsequent recruitment of chromatin-modifying proteins, such as HDAC1, to the IGF1R promoter-TBP-p53 complex.
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Key Words
- apoptosis
- atherosclerosis
- histone deacetylase (hdac)
- insulin-like growth factor 1 receptor (igf1r)
- p53
- vascular smooth-muscle cell (vsmc)
- apoe, apolipoprotein e
- chip, chromatin immunoprecipitation
- dmem, dulbecco's modified eagle's medium
- fcs, foetal calf serum
- hdac, histone deacetylase
- igf, insulin-like growth factor
- igfbp, igf binding protein
- igf1r, igf1 receptor
- igf1r-yf, kinase-dead mutant of igf1r
- ros, reactive oxygen species
- sma, smooth-muscle actin
- tbp, tata-box-binding protein
- t-(buooh), t-butyl hydroperoxide
- tfiid, transcription factor iid
- tsa, trichostatin a
- vsmc, vascular smooth-muscle cell
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Affiliation(s)
- Mary M. Kavurma
- *Division of Cardiovascular Medicine, University of Cambridge, Box 110, Addenbrooke's Hospital, Cambridge CB2 2QQ, U.K
| | - Nichola Figg
- *Division of Cardiovascular Medicine, University of Cambridge, Box 110, Addenbrooke's Hospital, Cambridge CB2 2QQ, U.K
| | - Martin R. Bennett
- *Division of Cardiovascular Medicine, University of Cambridge, Box 110, Addenbrooke's Hospital, Cambridge CB2 2QQ, U.K
| | - John Mercer
- *Division of Cardiovascular Medicine, University of Cambridge, Box 110, Addenbrooke's Hospital, Cambridge CB2 2QQ, U.K
| | - Levon M. Khachigian
- †Centre for Vascular Research, The University of New South Wales, Kensington 2052, NSW, Australia
| | - Trevor D. Littlewood
- *Division of Cardiovascular Medicine, University of Cambridge, Box 110, Addenbrooke's Hospital, Cambridge CB2 2QQ, U.K
- To whom correspondence should be addressed (email )
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Sukhanov S, Higashi Y, Shai SY, Itabe H, Ono K, Parthasarathy S, Delafontaine P. Novel effect of oxidized low-density lipoprotein: cellular ATP depletion via downregulation of glyceraldehyde-3-phosphate dehydrogenase. Circ Res 2006; 99:191-200. [PMID: 16778134 DOI: 10.1161/01.res.0000232319.02303.8c] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a classical glycolytic enzyme that is involved in cellular energy production and has important housekeeping functions. We used the natural prooxidant and proatherogenic molecule oxidized low-density lipoprotein (OxLDL) to determine a potential link between OxLDL-promoted oxidative stress, GAPDH expression, and smooth muscle cell energy metabolism. OxLDL but not native LDL (nLDL) produced a 60% to 100% dose- and time-dependent reduction of GAPDH protein. OxLDL increased reactive oxygen species (ROS) formation, including rapid elevation of H2O2 levels. OxLDL decreased intracellular catalase expression, likely contributing to the increase in H2O2. Antioxidants, anti-CD36 receptor antibody, NADPH oxidase, or lipoxygenase blockers decreased OxLDL-specific ROS and prevented GAPDH downregulation. 12/15-Lipoxygenase or p47phox deficiency resulted in attenuation of GAPDH downregulation, but 5-lipoxygenase suppression had no effect. OxLDL or exogenous H2O2 oxidized GAPDH thiols, decreasing GAPDH protein half-life and increasing GAPDH sensitivity to proteasome-mediated protein degradation in vitro. OxLDL- or small interfering RNA-specific downregulation of GAPDH resulted in 65% reduction in glycolysis rate and 82% decrease in ATP levels. In conclusion, our data demonstrate that OxLDL downregulated GAPDH via a H2O2-dependent decrease in protein stability. GAPDH protein damage resulted in marked depletion of cellular ATP levels. Our data have important implications for understanding the metabolic effect of OxLDL on the vessel wall and mechanism of atherogenesis.
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Affiliation(s)
- Sergiy Sukhanov
- Cardiology Section, Department of Medicine, Tulane University, 1430 Tulane Ave, SL-48, New Orleans, LA 70112-2699, USA
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