Atherogenic Mechanisms Of Arsenic
Sanjay Srivastava, Associate Professor Of Medicine
Medicineuniversity Of Louisville
Grant 1R01ES017260-01 from National Institute Of Environmental Health Sciences IRG: ZRG1
Abstract: The overall goal of this project is to understand the mechanisms by which exposure to arsenic accelerates or aggravates atherosclerosis. Exposure to arsenic-contaminated water is a global problem and results in the manifestation of multiple cardiovascular symptoms including hypertension, stroke, and myocardial infarction. Increased atherosclerosis is likely to be the major underlying cause of the increased risk of cardiovascular disease in an arsenic-exposed population. Accordingly, the intent of this proposal is to understand the mechanism by which arsenic accelerates or exacerbates atherogenesis in a well-controlled animal model. On the basis of supportive preliminary evidence, our central hypothesis is that arsenic promotes atherogenic changes in endothelial cells and in macrophages by inducing endoplasmic reticulum (ER) stress, which in turn triggers the unfolded protein response (UPR). To test this hypothesis, we will (1) delineate the contribution of ER stress and UPR to arsenic-mediated endothelial cell and macrophage activation; (2) examine the progression of atherogenesis in arsenic-exposed mice; and (3) elucidate the role of UPR in exacerbation of atherogenesis by arsenic. To accomplish these aims, we will examine whether exposure to arsenic induces ER stress and triggers UPR in endothelial cells and macrophages. We will identify which aspects of the UPR are triggered by arsenic and whether ER stress contributes to arsenic-induced activation of endothelial cells and foam cell formation. To assess how arsenic affects atherogenesis, we will examine early, intermediate, and advanced lesions for lipid accumulation, cellularity, inflammation, and oxidative stress in apoE-null mice exposed to arsenic. Bone marrow transplants from arsenic-exposed to non-exposed mice will be performed to delineate the specific contribution of macrophages to arsenic toxicity. To identify the in vivo role of UPR in arsenic toxicity, we will examine which components of ER stress and UPR are activated in the lesions of arsenic-exposed animals, and whether inhibition of the adaptive phase of UPR by deleting the ATF3 gene accelerates or treatment with chemical chaperones of protein folding inhibits lesion formation. Results of this project may lead to a better understanding of the mechanisms by which arsenic affects atherogenesis and how they could be therapeutically prevented. Large sections of human population in the US as well as Asia are exposed to high levels of arsenic in drinking water. Previous epidemiological studies show that people exposed to high levels of arsenic have a higher risk of developing cardiovascular disease. Nevertheless, the mechanisms by which arsenic elevates cardiovascular disease risk are not known. This project is designed to mimic human exposures to arsenic in an animal model and test whether exposure to arsenic increases the rate and/or the extent of atherosclerotic lesion formation in atherosclerosis-prone mice. The project seeks to understand the underlying molecular mechanisms by which arsenic increases atherosclerosis; which processes are affected; and which cellular and molecular mechanisms mediate the cardiovascular toxicity of arsenic. Results obtained from this project are likely to provide novel models for testing atherogenic effects of arsenic exposure, in developing a better understanding of how arsenic worsens atherosclerosis and how the atherogenic effects of arsenic could be ameliorated and treated
Project start date: 2009-06-15
Project end date: 2014-03-31
Sponsored Links Excellgen http://Excellgen.com
Grants awarded to Sanjay Srivastava
ATHEROGENIC MECHANISM OF LIPID PEROXIDATION-DERIVED ALDEHYDES
Sanjay Srivastava, Associate Professor
University Of Louisville, Office Of Grants Management, Louisville, Ky 40292
Grant 1R01HL095593-01A1 from National Heart, Lung, And Blood Institute
Abstract: The overall goal of this project is to understand the role of lipid peroxidation-derived aldehydes in atherosclerosis. Aldehydes such as 4-hydroxynal (HNE) and 1-palmitoyl-2-(5-oxovaleroyl)-3- glycero- phosphatidyl choline (POVPC) are the major bioactive products generated from the oxidation of LDL. Based on supportive preliminary studies, we propose to test hypothesis that accumulation of lipid-derived aldehydes in macrophages induces endoplasmic reticulum (ER) stress and triggers the unfolded protein response (UPR), leading to cytokine production and foam cell formation. The specific aims of this project are to (1) delineate the contribution of ER stress and UPR to aldehyde-mediated macrophage activation; (2) elucidate the role of UPR in regulating atherogenesis; and (3) examine the role of aldehyde metabolism in preventing ER stress and UPR in atherosclerotic lesions. To accomplish these aims, we will examine whether exposure of murine bone marrow derived macrophages to model lipid-derived aldehydes - HNE or POVPC induces ER stress and UPR. We will determine the extent and the nature of this response and identify which specific UPR-dependent signaling pathways are activated by aldehydes and how they contribute to macrophage activation, foam cell formation, and apoptosis. To examine the role of ER-stress and UPR during atherosclerotic lesion formation, we will determine stage-specific changes in ER stress and UPR in the arterial lesions of apoE-null mice. To probe causality, we will examine whether treatment with chemical chaperones, which assist protein folding, would decrease lesion formation and improve plaque stability. In addition, we will test whether genetic ablation of activating factor 3 (ATF3), a UPR-responsive gene, which is dramatically induced by lipid aldehydes, increases lesion progression and inflammation. To elucidate the role of aldehydes in inducing ER stress in atherosclerotic lesions, we will examine how genetic deletion or overexpression of aldose reductase, an enzyme which detoxifies both HNE and POVPC, affects aldehyde-induced macrophage activation and foam cell formation in culture and ER stress, UPR induction in the arterial lesions of apoE-null mice. Successful completion of this project may lead to a better understanding of the mechanisms by which lipid-derived aldehydes affect atherogenesis and how the effects of these aldehydes could be prevented or therapeutically minimized to decrease atherosclerosis. Oxidized lipids have been suggested to play a pivotal role in the formation of atherosclerotic lesions, nevertheless, the mechanisms by which these lipids or their products induce vascular injury, and promote plaque formation or rupture are unknown. Our studies are designed to test the hypothesis that accumulation of lipid-derived aldehydes in macrophages induces endoplasmic reticular (ER) stress and triggers unfolded protein response (UPR). We propose that lipid-derived aldehydes induce the transcription factor 3 (ATF3), which is associated with the alarm phase of UPR and genetic ablation of ATF3 exacerbates and pharmacological inhibition of ER-stress decreases atherogenesis. To examine that aldehydes are indeed causally involved in ER-stress and atherogenesis, we will examine whether macrophage specific overexpression or deletion of aldose reductase, which converts toxic aldehydes to innocuous alcohols, affects their atherogenic effects. Results obtained from this project will help in developing a better understanding, and potentially, novel therapeutic strategies for decreasing or managing atherosclerosis
Keywords: 2-Hydroxy-N, N, N-trimethylethanaminium; 4 hydroxynal; 4-HNE cpd; 4-hydroxy-2, 3-nal; 4-hydroxy-2-nal; 4-hydroxyn-2-al; APOE [{C0003595}]; ATF; ATF-3; Ablation; Affect; Alcohols; Aldehyde Reductase; Aldehydes; Alditol[{..}]NAD(P)+ 1-oxidoreductase; Aldose Reductase; Apo-E; ApoE; Apolipoprotein E; Apoptosis; Apoptosis Pathway; Arterial Fatty Streak; Asses; Atheroma; Atheromatous; Atheromatous degeneration; Atheromatous plaque; Atheroscleroses; Atherosclerosis; Atherosclerotic Cardiovascular Disease; Binding; Binding (Molecular Function); Blood Vessels; Bone Marrow; Causality; Cell Communication and Signaling; Cell Death; Cell Death, Programmed; Cell Signaling; Chaperone; Chemical Class, Alcohol; Chemicals; Choline; Choline Glycerophospholipids; Choline Phosphoglycerides; Donkey; Drug Metabolic Detoxication; EC 2.7.2-; Endoplasmic Reticulum; Enzymes; Equus asinus; Ergastoplasm; Ethanaminium, 2-hydroxy-N, N, N-trimethyl-; Etiology; Exposure to; Extracellular Signal-Regulated Kinases; Foam Cells; Genes; Genetic; Goals; INFLM; Immunity, Innate; Immunity, Native; Immunity, Natural; Immunity, Non-Specific; Inflammation; Inflammatory; Injury; Intermediary Metabolism; Intracellular Communication and Signaling; Knockout Mice; LDL oxidation; Laboratories; Lead; Lecithin; Lesion; Lesion by Stage; Lipid Peroxidation; Lipid-Laden Macrophage; Lipids; Lipoproteins; Low Density Lipoprotein oxidation; MAP kinase; MAPK; METBL; Macrophage Activation; Mammals, Mice; Mediating; Metabolic Detoxication, Drug; Metabolic Detoxification, Drug; Metabolic Drug Detoxications; Metabolic Processes; Metabolism; Metabolism of Toxic Agents; Mice; Mice, Knock-out; Mice, Knockout; Mitogen-Activated Protein Kinases; Modeling; Molecular; Molecular Chaperones; Molecular Interaction; Murine; Mus; Natural Immunity; Nature; Null Mouse; Pathway interactions; Pb element; Phase; Phosphatides; Phosphatidylcholines; Phospholipids; Play; Production; Protein Cleavage; Protein Degradation, Metabolic; Protein Degradation, Regulatory; Protein Turnover; Proteins; Proteolysis; Relative; Relative (related person); Research; Research Design; Reticuloendothelial System, Bone Marrow; Role; Rupture; Side; Signal Pathway; Signal Transduction; Signal Transduction Systems; Signaling; Staging; Streaks, Arterial Fatty; Stress; Study Type; Testing; Toxic effect; Toxicities; activating transcription factor; activating transcription factor 3; adduct; arterial lesion; atherogenesis; atheromatosis; atherosclerosis plaque; atherosclerotic lesions; atherosclerotic plaque; atherosclerotic vascular disease; base; biological adaptation to stress; biological signal transduction; cytokine; detoxification; disease causation; disease etiology; disease/disorder etiology; disorder etiology; endoplasmic reticulum stress; gene product; heavy metal Pb; heavy metal lead; improved; in vivo; macrophage; necrocytosis; new therapeutics; next generation therapeutics; novel therapeutics; overexpression; oxidation; oxidized lipid; pathway; prevent; preventing; protein degradation; protein folding; public health relevance; reaction; crisis; response; social role; stress response; stress; reaction; study design; vascular; vulnerable plaque
Relevance: Oxidized lipids have been suggested to play a pivotal role in the formation of atherosclerotic lesions, nevertheless, the mechanisms by which these lipids or their products induce vascular injury, and promote plaque formation or rupture are unknown. Our studies are designed to test the hypothesis that accumulation of lipid-derived aldehydes in macrophages induce endoplasmic reticular (ER) stress and triggers unfolded protein response (UPR). We propose that lipid-derived aldehydes induce the transcription factor 3 (ATF3), which is associated with the alarm phase of UPR and genetic ablation of ATF3 exacerbates and pharmacological inhibition of ER-stress decreases atherogenesis. To examine that aldehydes are indeed causally involved in ER-stress and atherogesis, we will examine whether macrophage specific overexpression or deletion of aldose reductase, which converts toxic aldehydes to innocuous alcohols, affects their atherogenic effects. Results obtained from this project will help in developing a better understanding, and potentially, novel therapeutic strategies for decreasing or managing atherosclerosis
Project start date: 2010-03-15
Project end date: 2014-02-28
Budget start date: 15-MAR-2010
Budget end date: 28-FEB-2011
PFA/PA: PA-07-070
1R01HL095593-01A1 (2010): $372500
ATHEROGENIC MECHANISMS OF ARSENIC
Sanjay Srivastava, Associate Professor
University Of Louisville, Office Of Grants Management, Louisville, Ky 40292
Grant 5R01ES017260-02 from National Institute Of Environmental Health Sciences
Abstract: The overall goal of this project is to understand the mechanisms by which exposure to arsenic accelerates or aggravates atherosclerosis. Exposure to arsenic-contaminated water is a global problem and results in the manifestation of multiple cardiovascular symptoms including hypertension, stroke, and myocardial infarction. Increased atherosclerosis is likely to be the major underlying cause of the increased risk of cardiovascular disease in an arsenic-exposed population. Accordingly, the intent of this proposal is to understand the mechanism by which arsenic accelerates or exacerbates atherogenesis in a well-controlled animal model. On the basis of supportive preliminary evidence, our central hypothesis is that arsenic promotes atherogenic changes in endothelial cells and in macrophages by inducing endoplasmic reticulum (ER) stress, which in turn triggers the unfolded protein response (UPR). To test this hypothesis, we will (1) delineate the contribution of ER stress and UPR to arsenic-mediated endothelial cell and macrophage activation; (2) examine the progression of atherogenesis in arsenic-exposed mice; and (3) elucidate the role of UPR in exacerbation of atherogenesis by arsenic. To accomplish these aims, we will examine whether exposure to arsenic induces ER stress and triggers UPR in endothelial cells and macrophages. We will identify which aspects of the UPR are triggered by arsenic and whether ER stress contributes to arsenic-induced activation of endothelial cells and foam cell formation. To assess how arsenic affects atherogenesis, we will examine early, intermediate, and advanced lesions for lipid accumulation, cellularity, inflammation, and oxidative stress in apoE-null mice exposed to arsenic. Bone marrow transplants from arsenic-exposed to non-exposed mice will be performed to delineate the specific contribution of macrophages to arsenic toxicity. To identify the in vivo role of UPR in arsenic toxicity, we will examine which components of ER stress and UPR are activated in the lesions of arsenic-exposed animals, and whether inhibition of the adaptive phase of UPR by deleting the ATF3 gene accelerates or treatment with chemical chaperones of protein folding inhibits lesion formation. Results of this project may lead to a better understanding of the mechanisms by which arsenic affects atherogenesis and how they could be therapeutically prevented. Large sections of human population in the US as well as Asia are exposed to high levels of arsenic in drinking water. Previous epidemiological studies show that people exposed to high levels of arsenic have a higher risk of developing cardiovascular disease. Nevertheless, the mechanisms by which arsenic elevates cardiovascular disease risk are not known. This project is designed to mimic human exposures to arsenic in an animal model and test whether exposure to arsenic increases the rate and/or the extent of atherosclerotic lesion formation in atherosclerosis-prone mice. The project seeks to understand the underlying molecular mechanisms by which arsenic increases atherosclerosis; which processes are affected; and which cellular and molecular mechanisms mediate the cardiovascular toxicity of arsenic. Results obtained from this project are likely to provide novel models for testing atherogenic effects of arsenic exposure, in developing a better understanding of how arsenic worsens atherosclerosis and how the atherogenic effects of arsenic could be ameliorated and treated
Keywords: APOE [{C0003595}]; ATF; ATF-3; Ablation; Adhesion Molecule; Affect; Animal Model; Animal Models and Related Studies; Animals; Apo-E; ApoE; Apolipoprotein E; Apoplexy; Apoptosis; Apoptosis Pathway; Arsenic; Arterial Fatty Streak; Arteriosclerosis; Asia; Asses; Atheroma; Atheromatous; Atheromatous degeneration; Atheromatous plaque; Atheroscleroses; Atherosclerosis; Atherosclerotic Cardiovascular Disease; Blood; Blood Coagulation Factor IV; Blood Pressure, High; Bone Marrow; Bone Marrow Transplant; Bone Marrow Transplantation; Ca++ element; Calcium; Cardiac infarction; Cardiovascular; Cardiovascular Body System; Cardiovascular Diseases; Cardiovascular system; Cardiovascular system (all sites); Carotid Atheroscleroses; Carotid Atherosclerotic Disease; Cause of Death; Cell Adhesion Molecules; Cell Communication and Signaling; Cell Death; Cell Death, Programmed; Cell Signaling; Cellularity; Cerebral Stroke; Cerebrovascular Apoplexy; Cerebrovascular Stroke; Cerebrovascular accident; Cessation of life; Chaperone; Chemicals; Chronic; Coagulation Factor IV; Collagen; Control Animal; Cytokine Activation; Cytokines, Chemotactic; Death; Disease; Disorder; Donkey; EC 2.7.2-; Endoplasmic Reticulum; Endothelial Cells; Epidemiologic Research; Epidemiologic Studies; Epidemiological Studies; Epidemiology Research; Equus asinus; Ergastoplasm; Exposure to; Extracellular Signal-Regulated Kinases; Factor IV; Foam Cells; Foot Diseases; Genes; Genetic; Goals; Grafting, Bone Marrow; Homologous Chemotactic Cytokines; Human; Human, General; Hydrogen Oxide; Hypertension; INFLM; Infant; Inflammation; Inflammatory; Ingestion; Intercrines; Intracellular Communication and Signaling; Ischemic Heart; Ischemic Heart Disease; Ischemic myocardium; Knockout Mice; Laboratories; Lead; Leiomyocyte; Lesion; Lipids; MAP kinase; MAPK; MMPs; Macrophage Activation; Mammals, Mice; Man (Taxonomy); Man, Modern; Marrow Transplantation; Matrix Metalloproteinases; Measures; Mediating; Mice; Mice, Knock-out; Mice, Knockout; Mitogen-Activated Protein Kinases; Modeling; Molecular; Molecular Chaperones; Mothers; Murine; Mus; Myocardial Infarct; Myocardial Infarction; Myocardial Ischemia; Myocytes, Smooth Muscle; Null Mouse; Organ System, Cardiovascular; Oxidative Stress; Pathway interactions; Pb element; Peripheral arterial disease; Phase; Population; Process; Production; Proteins; Reticuloendothelial System, Blood; Reticuloendothelial System, Bone Marrow; Risk Factors; Role; SIS cytokines; Signal Transduction; Signal Transduction Systems; Signaling; Smooth Muscle Cells; Smooth Muscle Myocytes; Smooth Muscle Tissue Cell; Staging; Streaks, Arterial Fatty; Stress; Stroke; Symptoms; T-Cells; T-Lymphocyte; Testing; Thymus-Dependent Lymphocytes; Toxic effect; Toxicities; Vascular Accident, Brain; Vascular Endothelial Cell; Vascular Hypertensive Disease; Vascular Hypertensive Disorder; Vascular, Heart; Water; activating transcription factor; activating transcription factor 3; arterial lesion; atherogenesis; atheromatosis; atherosclerosis plaque; atherosclerotic lesions; atherosclerotic plaque; atherosclerotic vascular disease; base; biological adaptation to stress; biological signal transduction; brain attack; cardiac infarct; cardiovascular disease risk; cardiovascular disorder; cardiovascular disorder risk; cell adhesion protein; cerebral vascular accident; chemoattractant cytokine; chemokine; circulatory system; coronary attack; coronary infarct; coronary infarction; cytokine; design; designing; disease/disorder; drinking water; endoplasmic reticulum stress; exposed human population; gene product; heart attack; heart infarct; heart infarction; heart ischemia; heavy metal Pb; heavy metal lead; high risk; human exposure; hyperpiesia; hyperpiesis; hypertensive disease; in vivo; macrophage; model organism; myocardial ischemia/hypoxia; myocardium ischemia; necrocytosis; novel; pathway; prevent; preventing; protein folding; public health relevance; reaction; crisis; response; social role; stress response; stress; reaction; stroke; thymus derived lymphocyte; transcription factor; vulnerable plaque
Relevance: Large sections of human population in the US as well as Asia are exposed to high levels of arsenic in drinking water. Previous epidemiological studies show that people exposed to high levels of arsenic have a higher risk of developing cardiovascular disease. Nevertheless, the mechanisms by which arsenic elevates cardiovascular disease risk are not known. This project is designed to mimic human exposures to arsenic in an animal model and test whether exposure to arsenic increases the rate and/or the extent of atherosclerotic lesion formation in atherosclerosis-prone mice. The project seeks to understand the underlying molecular mechanisms by which arsenic increases atherosclerosis; which processes are affected; and which cellular and molecular mechanisms mediate the cardiovascular toxicity of arsenic. Results obtained from this project are likely to provide novel models for testing atherogenic effects of arsenic exposure, in developing a better understanding of how arsenic worsens atherosclerosis and how the atherogenic effects of arsenic could be ameliorated and treated
Project start date: 2009-06-15
Project end date: 2014-03-31
Budget start date: 1-APR-2010
Budget end date: 31-MAR-2011
PFA/PA: PA-07-070
5R01ES017260-02 (2010): $329670
Metabolism And Detoxification Of Base Propenals
Sanjay Srivastava, Associate Professor Of Medicine
University Of Louisville Office Of Grants Management Louisville, Ky 40292
Grant 5R01ES011594-05 from National Institute Of Environmental Health Sciences IRG: ALTX
Abstract: The long-term goal of this project is to elucidate the metabolic pathways that regulate the cytotoxic and mutagenic potential of base propenals (BP) generated from oxidant-induced DNA damage. BP are derived from selective hydrogen ion from C4 of the deoxyribose ring, and their formation leads to strand scission. High concentrations of BPs are generated by anticancer drugs such as bleomycin and environmental agents such as Cr (VI). BPs have also been detected in normal, untreated, human cells, suggesting that they are produced from background DNA damage. The BPs are highly reactive unsaturated aldehydes which readily attack cellular nucleophiles such as glutathione and guanine. At high concentrations BPs are cytotoxic and cytostatic, whereas at low concentrations they form potentially mutagenic DNA adducts. Propenal-derived DNA adducts have been detected in high abundance in normal and cancerous human tissues and it has been suggested that they are derived mainly from BPs originating from oxidant-mediated DNA damage. Nonetheless, the metabolic processes that regulate the cytotoxic and mutagenic potential of BPs are not well understood. Based on our preliminary data and literature evidence, we propose that glutathione S-transferase (GSTP1-1) and aldose reductase (AR) are the major enzymes that participate in the metabolism of base propenals and that the sequential biotransformation by these enzymes prevents the toxicity and mutagenicity of base propenals. To test this hypothesis we will identify the major cellular and urinary metabolites of base propenals generated by COS-7 and HepG2 cells or mice exposed to radiolabeled adenine and thymine propenals (Aim 1). Next we will delineate the contribution of AR and GSTP1-1 to the overall metabolism of base propenals using pharmacological and molecular strategies, and elucidate the metabolism of propenal in AR-inhibitor treated or GSTP1-1 null mice (Aim 2). To test the catalytic efficiency of AR and GSTP1-1, we will examine their steady-state kinetic properties and determine whether product or substrate inhibition limits propenal metabolism via this pathway (Aim 3). Finally, to delineate the role of GSTP1-1 and AR in preventing the acute toxicity of base propenals and their ability to form DNA adducts (Aim 4), we will test whether inhibition or overexpression of these enzymes prevents base propenal cytotoxicity and adduct formation, and whether the mutagenic burden due to base propenal exposure is altered in GSTP1-1-null or AR inhibitor-treated mice. The results of these studies will provide a better understanding of the cytotoxic effects of DNA degradation products and the mechanism by which they indirectly induce potentially mutagenic DNA lesions. Our results may also help in designing more effective and targeted anticancer interventions and could lead to the identification of organ systems and individuals more sensitive to endogenous and environmental oxidants.
Keywords: DNA damage, cytotoxicity, detoxification, toxin metabolism, adduct, aldehyde reductase, biotransformation, enzyme activity, enzyme inhibitor, glutathione transferase, electrospray ionization mass spectrometry, genetically modified animal, high performance liquid chromatography, laboratory mouse, tissue /cell culture
Project start date: 2003-06-01
Project end date: 2009-03-31
5R01ES011594-05 (2007): $305100
5R01ES011594-04 (2006): $314213
5R01ES011594-03 (2005): $314213
5R01ES011594-02 (2004): $313678
1R01ES011594-01A1 (2003): $311897
Endothelial Metabolism Of Atherogenic Aldehydes
Sanjay Srivastava, Associate Professor Of Medicine
University Of Louisville Office Of Grants Management Louisville, Ky 40292
Grant 5R01HL065618-04 from National Heart, Lung, And Blood Institute IRG: PHRA
Abstract: The long-term goal of this project is to assess the contribution of lipid peroxidation to atherogenesis and to understand the mechanisms by which the products of lipid peroxidation contribute to the formation of atherosclerotic lesions. Previous studies have shown that the oxidation of low-density lipoprotein (LDL) generates toxic aldehydes, which could trigger and sustain the formation of atherosclerotic lesions. However, the contribution of these aldehydes to atherogenesis is unclear, and the mechanism by which they are metabolized and detoxified in the endothelium have not been examined. The intent of this project is to examine the endothelial metabolism of the LDL-derived aldehydes and to delineate their contribution to the initiation and the development of atherosclerotic lesions. To examine the biochemical processes that metabolize these aldehydes we will use 1-palmitoyl-2-(-5-oxovaleryl)-3-glycero phosphocholine (POVPC) and 4-hydroxy-trans-2-nonenal (HNE) as model aldehydes. These aldehydes respresent the most abundant esterified and non-esterified aldehydes generated during the oxidation of LDL. Our central hypothesis is that the polyol pathway enzyme aldose reductase (AR) catalyzes the major reductive pathway, common to the detoxification of both the esterified and non-esterifled aldehydes, and the AR-catalyzed pathway protects against the atherogenic effects of oxidized LDL. To test this hypothesis, in Aim 1, we will identify, quantify, and characterize the major products of POVPC and HNE in human endothelial cells in culture. To delineate the contribution of AR, in Aim 2, we will examine changes in the rate and extent of formaiton of the major metabolites in the presence of aldose reductase inhibitors and investigate the relationship between aldose reductase and other pathways of aldehyde metabolism due to phospholipases, platelet activating factor-acetylhydrolase and aldehyde dehydrogenase. To assess the toxicological significance of the aldose reductase-catalyzed pathway, we will examine whether inhibition of this enzyme enhances the extent of induction of the adhesion molecules ICAM-1 and VCAM in endothelial cells and increases the adhesion of monocytes to endothelial cells in culture. In Aim 3, we will examine the development of atherosclerotic lesions in apoE and LDL-receptor null mice and determine whether inhibition of aldose reductase exacerbates pre-atherosclerotic changes and increases the arterial abunbance of ICAM-1 and VCAM and whether this accelerates the formation of atherosclerotic lesions. The results of these studies will provide a better understanding of the mechanisms by which phospholipid oxidation promotes atherosclerosis, amd may lead to the identification of a novel pathway regulating the extent and the severity of arterial lesions. These studies could also form the basis of future assessments of individual risk for atherosclerosis due to differences in the vascular metabolism of aldehydes.
Keywords: aldehyde, aldehyde reductase, atherosclerosis, enzyme activity, lipid metabolism, low density lipoprotein, pathologic process, peroxidation, vascular endothelium, aldehyde dehydrogenase, atherosclerotic plaque, biochemistry, cell adhesion molecule, chemical synthesis, enzyme inhibitor, monocyte, phosphatidylcholine, gene targeting, genetically modified animal, immunocytochemistry, laboratory mouse, tissue /cell culture
Project start date: 2002-08-01
Project end date: 2008-07-31
5R01HL065618-04 (2005): $330750
5R01HL065618-03 (2004): $294000
5R01HL065618-02 (2003): $292000
Sponsored Links Excellgen http://Excellgen.com