Nox Isoforms and Vascular Cell Phenotype

Nox 亚型和血管细胞表型

• 批准号: 7172934
• 负责人: John F. Keaney
• 金额: $ 30.63万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-15 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7172934
• 关键词: 4-ethoxymethylene-2-phenyl-2-oxazoline-5-one; Adenovirus Vector; Age; Aged, 80 and over; Aging; Alzheimer' s Disease; Amyloid; Amyloid beta-Protein Precursor; Antioxidants; Arterial Injury; Arteries; Blood Vessels; Cardiovascular Diseases; Catalytic Domain; Cause of Death; Cell Adhesion Molecules; Cells; Cerebral Amyloid Angiopathy; Cerebral hemisphere hemorrhage; Characteristics; Clinical; Congestive Heart Failure; Data; Deposition; Diabetes Mellitus; Disease; Elderly; Endothelial Cells; Endothelium; Enzymes; Family; Framingham Heart Study; Free Radicals; Functional disorder; Hereditary Cerebral Amyloid Angiopathy; Hypertension; In Vitro; Investigation; Knowledge; Mediating; Mitochondria; Modeling; Mus; Myocardial Infarction; NADPH Oxidase; Neuraxis; Neurons; Numbers; Oxidation-Reduction; Peptides; Phenotype; Population; Protein Isoforms; Protein Overexpression; Proteins; Reactive Oxygen Species; Role; Rupture; Signal Transduction; Small Interfering RNA; Source; Stroke; Tetracycline; Tetracyclines; Toxic effect; Transgenic Mice; Variant; Vascular Diseases; Veins; aging brain; base; cardiovascular risk factor; design; gain of function; harman; hypercholesterolemia; insight; interest; loss of function; migration; neutrophil; novel; novel therapeutics; older patient; response; senescence; superoxide-generating NADPH oxidase; theories

Clinical manifestations of cardiovascular disease, such as heart attack, stroke, and congestive heart failure, are the number one cause of death in the developed world. Despite considerable interest in specific cardiovascular risk factors such as hypercholesterolemia, diabetes, and hypertension, data from the Framingham Heart Study indicate clearly the main determinant of incident cardiovascular disease is aging. Aged blood vessels are characterized by reduced control of antioxidant enzymes, an increased flux of reactive oxygen species, and vascular dysfunction. This flux of reactive oxygen species has proven to be a major determinant of vascular phenotype as a function of age, consistent with the "Free Radical Theory" of aging. This theory, originally proposed by Harman/1, pointed to the mitochondrion as the principal source of free radicals. However, there is now compelling evidence for multiple enzymatic sources of reactive oxygen species throughout blood vessels and particularly in the endothelium. Principle among these are the NADPH oxidase family of enzymes that are related to the classical neutrophil respiratory burst oxidase. We and others have found that endothelial cells contain two specific isoforms of the NADPH oxidase catalytic subunit (Nox); Nox2 and Nox4. The former is identical to the respiratory burst oxidase (GP91/phox, now Nox2), whereas the latter is novel. Considerable data indicate that excess vascular reactive oxygen species that are characteristic of vascular disease and aging are due, in part, from Nox enzymatic activity. Most investigation on Nox-derived reactive oxygen species and vascular disease has focused on Nox2. However, the role of Nox4 and how it differs with Nox2 with regard to vascular phenotype is not known. This is all the more problematic considering that Nox4 is the major Nox isoform in the vasculature. This proposal is designed to bridge this gap in knowledge and is based upon the hypothesis that reactive oxygen species produced by specific Nox isoforms is an important determinant of the maladaptive vascular phenotype that is characteristic of vascular disease and aging. The objective of this application, therefore, is to determine the role of specific Nox isoforms in controlling endothelial cell phenotype and elucidate the mechanisms involved. In order to achieve this objective, we will first characterize the NADPH oxidase catalytic subunit isoforms in endothelial cells with expect to their expression, subcellular localization, and subunit requirements. We will then use gain-of-function and loss-of-function strategies to determine the role of Nox isoforms in controlling endothelial cell phenotypes involving ROS such as NO bioactivity, adhesion molecule expression, proliferation, migration, and senescence. We will then go on to manipulate Nox4 expression in mice using stable siRNA expression or cell-specific Nox overexpression and examine the implications for vascular function and the response to arterial injury. Successful prosecution of these studies will provide mechanistic information on redox-mediated control of vascular cell phenotype and afford us the necessary insight to design new therapeutic strategies that focus on Nox-derived reactive oxygen species.

心血管疾病的临床表现，如心脏病发作、中风和充血性心力衰竭，是发达国家的头号死亡原因。尽管人们对高胆固醇血症、糖尿病和高血压等特定心血管危险因素非常感兴趣，但弗雷明汉心脏研究的数据清楚地表明，心血管疾病发生的主要决定因素是衰老。