Homocysteine and Endothelial Cell Growth Inhibition

同型半胱氨酸和内皮细胞生长抑制

• 批准号: 7595064
• 负责人: Hong Wang
• 金额: $ 37.5万
• 依托单位: TEMPLE UNIV OF THE COMMONWEALTH
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-05 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7595064
• 关键词: Accounting; Adenoviruses; Age; Aorta; Apolipoprotein E; Arteriosclerosis; Atherosclerosis; Biochemical; Blood Vessels; Cardiovascular Diseases; Cause of Death; Cell Cycle Progression; Cell Differentiation process; Cell Proliferation; Cell Therapy; Cells; Cellular biology; Consensus; Cyclin A; Cystathionine; DNA Methylation; DNA Methyltransferase; DNA Modification Methylases; Developed Countries; Developing Countries; Diabetes Mellitus; Disease; Elements; Endothelial Cells; Endothelium; Epigenetic Process; Etiology; Event; Gene Expression; Gene Targeting; Genes; Genetic; Genetic Transcription; Goals; Grant; Growth; High Prevalence; Homocysteine; Homocystine; Human; Hyperhomocysteinemia; In Vitro; Injury; Kidney Diseases; Laboratories; Lead; Lesion; Link; Metabolism; Modeling; Modification; Molecular; Monitor; Mus; Mutate; Myocardial Infarction; Natural regeneration; Organ; Postmenopause; RNA Interference; Risk Factors; Role; Signal Transduction; Smooth Muscle Myocytes; Stroke; Subarachnoid Hemorrhage; Techniques; Therapeutic; Vascular Diseases; Vascular Endothelial Cell; Woman; base; cell growth; cell type; chromatin remodeling; cyclin D2; embryonic stem cell; in vivo; injured; insight; neointima formation; novel therapeutic intervention; promoter; repaired; research study

DESCRIPTION (provided by applicant): The overall objective of this revised competitive renewal application is to determine the molecular mechanisms responsible for Hyperhomocysteinemia (HHcy)-induced endothelial cell (EC) growth inhibition. We provided initial evidence demonstrating that pathophysiologically relevant concentrations of homocysteine (Hcy) inhibit EC growth, but not that of other cell types, through a hypomethylation related mechanism. In the previous grant period, we discovered that Hcy inhibits cyclin A transcription, DNA methyltransferase 1 (DNMT1) activity and DNA methylation in cyclin A promoter, and that adenovirus-transduced expression of cyclin A and DNMT1 genes rescued EC growth from the inhibitory effect of Hcy. Our in vivo studies indicate that HHcy impairs endothelial function and eNOS activity via PKC activation, and that HHcy impaired reendothelialization and increased neointimal formation in mice. Our basic hypothesis is that that Hcy impairs reendothelialization via inhibition of EC proliferation, and contribute, to the increased atherosclerosis in HHcy. This project will study this hypothesis utilizing three linked specific aims. First, in Aim 1, we will explore the regulatory mechanisms of Hcy-induced cyclin D2/D3 suppression in EC. Second, in Aim 2, we will Determine biochemical basis of Hcy-hypomethylation and growth inhibition in EC. Finally, in Aim 3, we will examine the effect of EC therapy in post-injury reendothelialization and neointima formation in HHcy mice. We believe that completion of the specific aims should provide valuable new information to establish the links between HHcy and atherosclerosis, and lead to therapeutic advantage. PUBLIC HUMAN RELEVANCE It has been suggested that HHcy accounts for the higher prevalence of CVD in renal disease, diabetes, ageing and in postmenopausal women that is not explained by traditional risk factors. However, the underlying mechanism is largely unknown and the role of homocysteine (Hcy)-induced endothelial growth inhibition in CVD is unclear. We have previously demonstrated that Hcy exerts highly selective inhibitory effect on cyclin A transcription and EC growth through a hypomethylation related mechanism, which blocks cell cycle progression and endothelium regeneration. Since endothelial injury is an early event in vascular disease, and since endothelial regeneration determines the onset of atherosclerosis, we hypothesize that Hcy promotes atherosclerosis by impairing reendothelialization via inhibition of EC proliferation. In this proposal, we propose to investigate the role and mechanisms of HHcy in altering EC metabolism and EC biology, with the goal of identifying the underlying mechanisms, using in vitro and in vivo approaches.

描述（由申请人提供）：本修订版竞争性更新申请的总体目标是确定高同型半胱氨酸（HHcy）诱导的内皮细胞（EC）生长抑制的分子机制。我们提供的初步证据表明，病理生理相关浓度的同型半胱氨酸（Hcy）抑制EC的生长，但不是其他类型的细胞，通过低甲基化相关的机制。在前期的研究中，我们发现Hcy抑制细胞周期蛋白A的转录、DNA甲基转移酶1（DNMT 1）的活性和细胞周期蛋白A启动子的DNA甲基化，并发现腺病毒介导的细胞周期蛋白A和DNMT 1基因的表达可使EC的生长免受Hcy的抑制。我们在体内的研究表明，HHcy损害内皮功能和eNOS活性通过PKC激活，和HHcy损伤再内皮化和增加新生内膜形成在小鼠。我们的基本假设是，同型半胱氨酸通过抑制EC增殖而损害再内皮化，并有助于增加HHcy中的动脉粥样硬化。本项目将利用三个相互关联的具体目标来研究这一假设。首先，在目的1中，我们将探讨Hcy诱导的EC细胞周期蛋白D2/D3抑制的调节机制。第二，在目标2中，我们将确定EC中Hcy低甲基化和生长抑制的生化基础。最后，在目标3中，我们将检查EC治疗对HHcy小鼠损伤后再内皮化和新生内膜形成的影响。我们相信，特定目标的完成将为建立HHcy与动脉粥样硬化之间的联系提供有价值的新信息，并导致治疗优势。 公众与人类的相关性已经表明，高同型半胱氨酸是肾脏疾病、糖尿病、老龄化和绝经后妇女中CVD患病率较高的原因，而传统的风险因素无法解释。然而，潜在的机制在很大程度上是未知的，同型半胱氨酸（Hcy）诱导的血管内皮生长抑制在CVD中的作用尚不清楚。我们以前已经证明，同型半胱氨酸通过低甲基化相关机制对细胞周期蛋白A转录和EC生长产生高度选择性的抑制作用，从而阻断细胞周期进程和内皮再生。由于内皮损伤是血管疾病的早期事件，并且由于内皮再生决定动脉粥样硬化的发生，我们假设Hcy通过抑制EC增殖损害再内皮化来促进动脉粥样硬化。在这个建议中，我们建议调查的作用和机制，高同型半胱氨酸在改变EC代谢和EC生物学，确定潜在的机制，使用在体外和体内的方法的目标。