Homocysteine-induced Endothelial Cell Growth Inhibition

同型半胱氨酸诱导的内皮细胞生长抑制

• 批准号: 6838789
• 负责人: Hong Wang
• 金额: $ 10.53万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-01-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6838789
• 关键词: arteriosclerosis; biological signal transduction; cell growth regulation; chemical structure function; genetic screening; guanine nucleotide binding protein; homocysteine; homocystinuria; laboratory mouse; methylation; methyltransferase; molecular pathology; pathologic process; proteomics; radiotracer; tissue /cell culture; vascular endothelium

DESCRIPTION (provided by applicant): Hyperhomocysteinemia is an independent risk factor for myocardial infarction and stroke, yet the mechanisms by which homocysteine (Hcy) promotes arteriosclerosis are not clear. Most of the reported biological effects of Hcy in vascular cells have been attributed to oxidative mechanisms, which were observed at Hcy concentrations higher than 1 mM or higher, and can be mimicked by cysteine, another nonpathogenic biothiol. Thus, a biochemical mechanism unique to Hcy remains to be identified. We have proposed hypomethylation as a specific mechanism by which Hcy induces vascular injury and leads to cardiovascular disease. The basic hypothesis of the ongoing and this proposed projects is that Hcy, at clinically relevant concentrations, selectively inhibits EC growth through a hypomethylation-related mechanism. The ongoing research is designed to investigate the role of Ras demethylation in Hcy-EC growth, to dissect the mechanism in Hcy signaling using cellular and animal models. Because damage to EC is a key feature of arteriosclerosis, the growth inhibition of EC may represent an important mechanism to explain Hcy-induced arteriosclerosis. In the proposed study, we hypothesize that hypomethylation of other molecules may also play an important role in Hcy-related EC growth inhibition. We added two new aims to characterize methylation status of genomic DNA and protein, to examine the activities of histone methyltransferase in Hcy-treated EC (Aim 4), and to identify new functional target genes using retrovirus-mediated genetic screening and radiolabelled methylation sensitive two-dimensional electrophoresis proteomics (Aim 5). These two new aims are expansion of the funded project and would explore key functional molecular mechanisms by which Hcy inhibit EC growth. The broad, long-term objective of this proposal is to elucidate Hcy signaling in EC growth inhibition, and to evaluate its importance in the role of atherogenesis in Hcy pathology. If we can identify the key events in Hcy-induced arteriosclerosis, genetic or biochemical approaches to block these steps could lead to therapeutic advantage.

描述（由申请人提供）： 高同型半胱氨酸血症是心肌梗死和脑卒中的独立危险因素，但同型半胱氨酸（Hcy）促进动脉硬化的机制尚不清楚。 大多数报道的血管细胞中Hcy的生物学效应归因于氧化机制，这是在Hcy浓度高于1 mM或更高时观察到的，并且可以被半胱氨酸（另一种非致病性生物硫醇）模仿。 因此，同型半胱氨酸独特的生化机制仍有待确定。 我们提出低甲基化是同型半胱氨酸诱导血管损伤并导致心血管疾病的一种特定机制。 正在进行的和这个拟议的项目的基本假设是，同型半胱氨酸，在临床相关的浓度，选择性地抑制EC的增长，通过低甲基化相关的机制。 本研究旨在探讨Ras去甲基化在Hcy EC生长中的作用，并利用细胞和动物模型分析Hcy信号转导机制。 由于EC的损伤是动脉硬化的一个重要特征，EC的生长抑制可能是解释Hcy诱导的动脉硬化的重要机制。 在这项研究中，我们假设其他分子的低甲基化也可能在Hcy相关的EC生长抑制中发挥重要作用。 我们增加了两个新的目标，以表征基因组DNA和蛋白质的甲基化状态，以检查组蛋白甲基转移酶的活性在Hcy处理EC（目标4），并确定新的功能靶基因，使用逆转录病毒介导的遗传筛选和放射性标记的甲基化敏感的二维电泳蛋白质组学（目标5）。 这两个新的目标是扩大资助的项目，并将探索关键的功能分子机制，同型半胱氨酸抑制EC的生长。 这个建议的广泛的，长期的目标是阐明Hcy信号在EC生长抑制，并评估其在动脉粥样硬化的作用在Hcy病理的重要性。 如果我们能够确定Hcy诱导动脉硬化的关键事件，那么阻断这些步骤的遗传或生化方法可能会带来治疗优势。