SP(A) AND ATHEROSCLEROSIS IN TRANSGENIC MICE

转基因小鼠中的 SP(A) 和动脉粥样硬化

• 批准号: 2226838
• 负责人: RICHARD M LAWN
• 金额: $ 36.61万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-07-18 至 1998-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2226838
• 关键词: Adenoviridae; apolipoproteins; atherosclerosis; blood lipoprotein; cell growth regulation; cell migration; cryostat; gene expression; genetic enhancer element; genetic promoter element; genetically modified animals; human genetic material tag; human subject; immunocytochemistry; laboratory mouse; molecular pathology; nucleic acid repetitive sequence; plasminogen; protein biosynthesis; protein isoforms; protein structure; recombinant DNA; reporter genes; transforming growth factors; vascular smooth muscle

Elevated plasma concentration of the lipoprotein Lp(a) is a major independent risk factor for atherosclerosis and restenosis. This association, as well as explanations for the enormous inter-individual differences in Lp(a) levels, have largely been based on data from population surveys and family studies. In addition, the pathologic activity of Lp(a) remains unknown, although in vitro studies have suggested possible functions which remain unconfirmed in vivo. Hence, the basic aims of this proposed research are to use transgenic mice to examine in vivo the genetic determinants of apo(a) gene expression and its effects on blood vessels. In order to directly investigate the role of two major hypothesized determinants of Lp(a) plasma concentration, transcription of the apo(a) gene and the variable size of apo(a) isoforms, we propose to study the effects of promoter/enhancer sequences and kringle domain repeat number on Lp(a) plasma levels in transgenic mice and mice transfected with recombinant DNA via non-replicating adenovirus. Apo(a) flanking genomic DNA from several individuals whose apo(a) alleles are associated with high or low plasma levels, as well as in vitro mutagenized gene sequences, will be linked to apo(a) and reporter cDNA for transfection. The level of resulting hepatic mRNA and plasma apo(a) concentration will be determined. Mice will also be made to express apo(a) mini genes containing varying numbers of kringle repeats. Apo(a) transcription, protein synthetic rates, plasma levels, and plasma half lives will be compared in animals containing constructs of identical promoter elements linked to protein coding regions of different size. These studies will assess the effect of various steps in expression and metabolism of apo(a) that could account for the rough, inverse correlation between apo(a) isoform size and concentration reported in population studies. The association between plasma concentration of Lp(a) and atherosclerosis in humans is well established. But despite a number of attractive hypotheses with varied degrees of in vitro support, the pathophysiology of Lp(a) remains unknown. We propose to use transgenic mice as manipulatable models of the activity of Lp(a). In this model, we will study the effects of apo(a) concentration and its interaction with other proteins on atherosclerosis. Key variants in the sequence of the apo(a) protein will also be tested. In addition, we will examine the time course of arterial changes associated with expression of the transgenes and test the hypothesis that apo(a) promotes the proliferation and migration of vascular smooth muscle cells by interfering with the activation of plasminogen and TGF-beta.

脂蛋白LP（A）的血浆浓度升高是主要的 动脉粥样硬化和再狭窄的独立危险因素。这 关联，以及对个体间的解释 LP（a）级别的差异主要基于 人口调查和家庭研究。另外，病理学 LP（a）的活性仍然未知，尽管体外研究具有 建议在体内未经证实的可能功能。因此， 这项拟议的研究的基本目的是使用转基因小鼠检查 在体内Apo（A）基因表达及其作用的遗传决定因素 在血管上。 为了直接研究两个主要假设的作用 LP（A）血浆浓度的决定因素，Apo（a）的转录 基因和Apo（A）同工型的可变大小，我们建议研究 启动子/增强子序列和kringle域重复编号对 LP（A）转染的转基因小鼠和小鼠的血浆水平 重组DNA通过非复制腺病毒。 Apo（a）基因组侧面 来自Apo（a）等位基因高的几个人的DNA 或低血浆水平以及体外诱变基因序列，将 与Apo（a）和报告基因cDNA链接进行转染。水平 将确定产生的肝mRNA和血浆APO（A）浓度。 也将使小鼠表达apo（a）迷你基因，其中包含不同 kringle重复的数量。 APO（a）转录，蛋白质合成速率， 在动物中比较血浆水平和血浆半寿命 包含与蛋白质相关的相同启动子元件的构造 大小不同的编码区域。这些研究将评估 可以说明Apo的表达和代谢的各种步骤 对于Apo（a）同工型大小和 人口研究中报道的浓度。 LP（A）和动脉粥样硬化的血浆浓度之间的关联 在人类中，已经建立了很好的建立。但是尽管有很多吸引人 具有不同程度的体外支持的假设， LP（A）仍然未知。我们建议将转基因小鼠用作可操作的 LP（a）活动的模型。在此模型中，我们将研究效果 Apo（a）浓度及其与其他蛋白质的相互作用 动脉粥样硬化。 Apo（A）蛋白序列中的关键变体将 也可以测试。此外，我们将检查动脉的时间过程 变化与转基因的表达相关，并测试 Apo（a）促进的假设促进了 血管平滑肌细胞通过干扰激活 纤溶酶原和TGF-β。