MOLECULAR MECHANISMS OF CONTROL OF AORTIC FIBROSIS

控制主动脉纤维化的分子机制

• 批准号: 6411229
• 负责人: Herbert Marcus Kagan
• 金额: $ 30.86万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-12-01 至 2001-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6411229
• 关键词: amine oxidoreductase; aorta disorder; atherosclerosis; enzyme activity; enzyme induction /repression; fibrosis; genetic promoter element; genetic regulatory element; lysine; posttranslational modifications; protein localization; tissue /cell culture; transcription factor; transfection; vascular smooth muscle

The excess deposition of extracellular fibers of collagen and elastin in fibrotic arterial disease is a major source of the mass of occlusive vascular lesions. Lysyl oxidase, the enzyme which catalyzes the oxidation of lysine and cross linking of collagen and elastin, plays a critical, controlling role in this process and thus is a vulnerable target for intervention in fibrotic arterial disease. Nevertheless, very little information presently exists about regulation of this catalyst at the transcriptional or post-transcriptional levels. However, our preliminary data now reveal that the expression of this enzyme is strongly up- regulated in vascular smooth muscle cells at the post-transcriptional level as proliferation is inhibited by transforming growth factor-beta1, evidenced by a marked reduction in rates of mRNA decay. In addition, analyses of lysyl oxidase promoter constructs in aortic smooth muscle cells reveal that promoter activity is prominently affected by serum- dependent changes in cell proliferation and co-transfection with B-myb. The molecular bases of this important regulatory effects will be analyzed in this project, determining the cis-elements in LO mRNA in the LO promoter mediating these effects, and characterizing the protein trans- acting factors that specifically interact with them under each perturbed condition. In addition, we have evidence by microscopic, immunochemical and enzymatic approaches that lysyl oxidase is prominently localized and appears to function within the nucleus of the arterial smooth muscle cell. The significance of this finding will be pursued, determining the nuclear protein substrates and products generated within them by the enzyme, and assessing for the functional consequences of this localization on proliferation and gene expression by the arterial smooth muscle cell. These studies will be carried out in close collaboration with other projects within this program as a natural consequence of their interests in collagen and elastin and in B-myb and adenosine ligands which we have noted perturb the expression of this enzyme.

胶原蛋白和弹性蛋白的细胞外纤维过度沉积 纤维化动脉疾病是闭塞性动脉瘤的一个主要来源 血管病变。赖氨酰氧化酶，催化氧化的酶 赖氨酸以及胶原蛋白和弹性蛋白的交联，起着至关重要的作用， 在此过程中发挥控制作用，因此是一个脆弱的目标 干预纤维化动脉疾病。尽管如此，还是很少 目前存在有关该催化剂监管的信息 转录或转录后水平。然而，我们的初步 现在的数据表明，这种酶的表达强烈上调 血管平滑肌细胞的转录后调控 转化生长因子-β1 抑制增殖， mRNA 衰减率显着降低就证明了这一点。此外， 主动脉平滑肌中赖氨酰氧化酶启动子构建体的分析 细胞显示启动子活性显着受血清影响 细胞增殖和与 B-myb 共转染的依赖性变化。 将分析这种重要调节作用的分子基础 在这个项目中，确定LO mRNA中的顺式元件 启动子介导这些效应，并表征蛋白质反式 在每个扰动下与它们具体相互作用的作用因素 健康）状况。此外，我们还通过显微镜、免疫化学等方法获得证据 和酶促方法表明赖氨酰氧化酶是显着局部化的并且 似乎在动脉平滑肌细胞的细胞核内发挥作用。 这一发现的重要性将被追究，确定核 蛋白质底物和酶在其中产生的产物，以及 评估这种本地化的功能后果 动脉平滑肌细胞的增殖和基因表达。 这些研究将与其他机构密切合作进行 该计划内的项目是其利益的自然结果 我们拥有的胶原蛋白和弹性蛋白以及 B-myb 和腺苷配体 注意到扰乱了这种酶的表达。