Mechanisms of cLDL-Induced Endothelial Injury

cLDL 引起的内皮损伤的机制

• 批准号: 8246097
• 负责人: Sudhir V Shah
• 金额: --
• 依托单位: CENTRAL ARKANSAS VETERANS HLTHCARE SYS
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-10-01 至 2015-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8246097
• 关键词: Accounting; Acute; Adhesions; Adult; Apolipoprotein E; Atherosclerosis; Attenuated; Biological; Blocking Antibodies; Blood; Blood Urea Nitrogen; CD36 gene; Cardiovascular Diseases; Cardiovascular system; Case-Control Studies; Caspase; Cause of Death; Cell Adhesion Molecules; Cell Death; Cells; Cessation of life; Chelating Agents; Cholesterol; Chronic; Chronic Kidney Failure; Common carotid artery; Consumption; Coronary; Coronary artery; DNA; DNA Fragmentation; Data; Deoxyribonuclease I; Deoxyribonucleases; Development; Diet; Endothelial Cells; Enzymes; Event; Exposure to; Fatty acid glycerol esters; Functional disorder; Future; General Population; Generations; Genetic; Health; Human; Hydrogen Peroxide; Immunohistochemistry; In Vitro; Injection of therapeutic agent; Injury; Iron; Iron Chelation; Knock-out; Knockout Mice; LOX gene; Lipoprotein (a); Low-Density Lipoproteins; Mediating; Mediator of activation protein; Methods; Modeling; Molecular Target; Mus; Operative Surgical Procedures; Oxidants; Oxygen; Pathway interactions; Patients; Plasma; Prevalence; Prevention; Process; Proteins; RNA Interference; Regulation; Risk; Risk Factors; Role; Sampling; Smooth Muscle Myocytes; Superoxides; Testing; Thick; Toxic effect; United States; Urea; Uremia; Vascular Endothelial Cell; Veterans; Wild Type Mouse; atherogenesis; cardiovascular risk factor; caspase-3; cell injury; cell type; cellular targeting; cytotoxicity; data modeling; disability; drinking water; endonuclease G; feeding; follow-up; improved; in vivo; inhibitor/antagonist; intima media; monocyte; mortality; mouse model; nuclease; prevent; research study; response; scavenger receptor; therapeutic target; treatment strategy; Accounting; Acute; Adhesions; Adult; Apolipoprotein E; Atherosclerosis; Attenuated; Biological; Blocking Antibodies; Blood; Blood Urea Nitrogen; CD36 gene; Cardiovascular Diseases; Cardiovascular system; Case-Control Studies; Caspase; Cause of Death; Cell Adhesion Molecules; Cell Death; Cells; Cessation of life; Chelating Agents; Cholesterol; Chronic; Chronic Kidney Failure; Common carotid artery; Consumption; Coronary; Coronary artery; DNA; DNA Fragmentation; Data; Deoxyribonuclease I; Deoxyribonucleases; Development; Diet; Endothelial Cells; Enzymes; Event; Exposure to; Fatty acid glycerol esters; Functional disorder; Future; General Population; Generations; Genetic; Health; Human; Hydrogen Peroxide; Immunohistochemistry; In Vitro; Injection of therapeutic agent; Injury; Iron; Iron Chelation; Knock-out; Knockout Mice; LOX gene; Lipoprotein (a); Low-Density Lipoproteins; Mediating; Mediator of activation protein; Methods; Modeling; Molecular Target; Mus; Operative Surgical Procedures; Oxidants; Oxygen; Pathway interactions; Patients; Plasma; Prevalence; Prevention; Process; Proteins; RNA Interference; Regulation; Risk; Risk Factors; Role; Sampling; Smooth Muscle Myocytes; Superoxides; Testing; Thick; Toxic effect; United States; Urea; Uremia; Vascular Endothelial Cell; Veterans; Wild Type Mouse; atherogenesis; cardiovascular risk factor; caspase-3; cell injury; cell type; cellular targeting; cytotoxicity; data modeling; disability; drinking water; endonuclease G; feeding; follow-up; improved; in vivo; inhibitor/antagonist; intima media; monocyte; mortality; mouse model; nuclease; prevent; research study; response; scavenger receptor; therapeutic target; treatment strategy

DESCRIPTION (provided by applicant): The prevalence of chronic kidney disease (CKD) is increasing worldwide. In the United States, over 20 million adults have CKD, and traditional cardiovascular risk factors do not account for this. Blood urea dissociates to form cyanate that may alter proteins including low-density lipoprotein (LDL) by a process known as carbamylation. Our recent studies demonstrate that cLDL has all of the biological effects relevant to atherosclerosis: (a) cLDL induces injury to human coronary artery endothelial cells; (b) it induces adhesion molecule expression and monocyte adhesion on human coronary artery endothelial cells; and (c) it causes proliferation of human coronary artery smooth muscle cells. In addition, we have demonstrated that elevated plasma cLDL concentration from either chronic kidney failure or chronic urea consumption results in the development of aortic atherosclerosis in mice. Our case-control study in uremic patients revealed a strong positive correlation between elevated cLDL and an increase in common carotid artery intima-media thickness (IMT), an accepted quantifiable marker of early atherosclerosis. One of the major events that occurs in response of cLDL exposure to endothelial cells is the induction of DNA fragmentation and cell death. The mechanisms by which cLDL induces endothelial cell injury, an early step in atherosclerosis, are not known. The central hypothesis of this proposal is that cLDL elevated by CKD induces endothelial cell injury by activating EndoG to promote atherosclerosis, and that inactivation of endothelial EndoG will blunt endothelial cell death and atherogenesis in uremic mice. Our preliminary studies show that endothelial cell death induced by cLDL depends on the expression of endonuclease G (EndoG), the nuclease associated with caspase-independent DNA fragmentation. Ex vivo experiments with primary endothelial cells isolated from wild-type (WT) and EndoG null knockout (KO) mice demonstrated that KO cells are partially protected against cLDL toxicity compared to WT cells. Our results showed increased number of floating endothelial cells after cLDL injection compared to nLDL in WT mice but not in KO mice. These data point to EndoG as an important mediator of cLDL toxicity to endothelial cells, and suggest that EndoG is a potential therapeutic target for cLDL cytotoxicity and, potentially, atherosclerosis. To study the cLDL-EndoG pathway, we plan: Aim 1. Determine molecular and cellular targets of cLDL causing activation of EndoG in vitro and in vivo. Aim 2. Evaluate the role of likely upstream regulators of EndoG in cLDL-induced endothelial cell death in vitro and in vivo. Aim 3. Test whether genetic inactivation of EndoG or inhibition of mechanisms upregulating EndoG attenuate uremia/cLDL-induced endothelial cell injury and atherosclerosis. Recent studies showed that among veterans, traditional cardiovascular risk factors CVD and CKD are highly prevalent, and CKD is associated with an increased risk of baseline CVD and follow-up mortality. Our study is aimed to determine whether regulation of the cLDL mediator EndoG or its upstream mechanisms may be beneficial for protection against acute endothelial injury and atherosclerosis induced by cLDL. Therefore, the results of this study may eventually save human lives, improve the health and well being of veterans, and decrease the number of disabilities among veterans and in the general population. PUBLIC HEALTH RELEVANCE: In the United States, over 20 million adults, many of whom are veretans, have chronic kidney disease associated with chronic cardiovascular disease, and the reason for this is unknown. Our recent studies showed that a form of cholesterol called carbamylated low-density lipoprotein (cLDL) results from chronic kidney disease and induces cardiovascular disease. Our preliminary data additionally show that cLDL acts by causing death of endothelial cells, which cover blood vessles inside. In the proposed study, we plan to determine if cLDL causes endothelial cell death by activating DNA-degrading enzyme, endonuclease G (EndoG), and if an inactivation of EndoG may prevent from cardiovascular disease. The results of this study may eventually save human lives, improve the health and well being of veterans, and decrease the number of disabilities among veterans and in the general population.

描述（由申请人提供）： 慢性肾脏疾病（CKD）的患病率在全球范围内增加。在美国，超过2000万成年人患有CKD，传统的心血管危险因素并不能解释这一点。血尿素解离形成氰酸盐，可能通过称为氨基甲基化的过程改变蛋白质，包括低密度脂蛋白（LDL）。我们最近的研究表明，CLDL具有与动脉粥样硬化有关的所有生物学作用：（a）CLDL诱导人类冠状动脉内皮细胞的损伤； （b）它诱导人冠状动脉内皮细胞上的粘附分子表达和单核细胞粘附； （c）它导致人类冠状动脉平滑肌细胞的增殖。此外，我们已经证明，慢性肾衰竭或慢性尿素消耗的血浆CLDL浓度升高会导致小鼠主动脉粥样硬化的发展。我们对尿毒症患者的病例对照研究表明，CLDL升高与普通颈动脉内膜膜厚度（IMT）之间存在很强的正相关，这是早期动脉粥样硬化的可接受的可量化标志物。 CLDL暴露于内皮细胞的反应时发生的主要事件之一是诱导DNA碎片和细胞死亡。 CLDL诱导内皮细胞损伤的机制（动脉粥样硬化的早期步骤）尚不清楚。 该提议的中心假设是，CKD升高的CLDL通过激活内向仪促进动脉粥样硬化而诱导内皮细胞损伤，并且内皮内皮内og的失活会钝化内皮细胞死亡和尿毒症小鼠的动脉粥样硬化。我们的初步研究表明，由CLDL诱导的内皮细胞死亡取决于核酸内切酶G（内og）的表达，核酸内切酶G（内og）是与caspase非依赖性DNA碎片相关的核酸酶。从野生型（WT）和Endog null敲除（KO）小鼠分离的原代内皮细胞的离体实验表明，与WT细胞相比，KO细胞对CLDL毒性有部分保护。我们的结果表明，与WT小鼠中的NLDL相比，CLDL注射后浮动内皮细胞的数量增加，而在KO小鼠中则没有。这些数据将endog作为CLDL毒性的重要介质对内皮细胞的重要介质，并表明内og是CLDL细胞毒性和可能是动脉粥样硬化的潜在治疗靶标。为了研究CLDL-endog途径，我们计划：目标1。确定CLDL的分子和细胞靶标，导致体外和体内激活内生的激活。 AIM 2。评估可能在CLDL诱导的内皮细胞死亡体外和体内可能上游调节剂的作用。 AIM 3。测试遗传灭活内生的遗传灭活或抑制上调内射线的机制，导致尿毒症/CLDL诱导的内皮细胞损伤和动脉粥样硬化。 最近的研究表明，在退伍军人中，传统的心血管危险因素CVD和CKD非常普遍，CKD与基线CVD和随访死亡率的风险增加有关。我们的研究旨在确定对CLDL介体的调节或其上游机制的调节是否可能有益于防止急性内皮损伤和CLDL引起的动脉粥样硬化。因此，这项研究的结果最终可以挽救人类的生命，改善退伍军人的健康和健康，并减少退伍军人和普通人群中的残疾人数。 公共卫生相关性： 在美国，超过2000万成年人，其中许多是veretans，患有与慢性心血管疾病有关的慢性肾脏疾病，原因是未知的。我们最近的研究表明，一种称为甲基化的低密度脂蛋白（CLDL）的胆固醇形式来自慢性肾脏疾病并诱导心血管疾病。我们的初步数据还表明，CLDL通过导致内皮细胞死亡而起作用，内皮细胞覆盖了内部的血管。在拟议的研究中，我们计划通过激活DNA降解酶，核酸内核酸内切酶G（内生）来确定CLDL是否导致内皮细胞死亡，并且如果内og灭活可能会阻止心血管疾病。这项研究的结果最终可以挽救人类的生命，改善退伍军人的健康和健康，并减少退伍军人和普通人群中的残疾人数。