MOLECULAR MECHANISMS OF CONTROL OF AORTIC FIBROSIS

控制主动脉纤维化的分子机制

• 批准号: 6564785
• 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: 2001
• 资助国家: 美国
• 起止时间: 2001-12-01 至 2002-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6564785
• 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.

胶原和弹性蛋白的细胞外纤维的过度沉积， 纤维化动脉疾病是闭塞性动脉瘤的主要来源。 血管病变赖氨酰氧化酶，催化氧化的酶 赖氨酸和胶原蛋白和弹性蛋白的交联，起着关键的作用， 在这一过程中的控制作用，因此是一个脆弱的目标， 纤维化动脉疾病的干预。然而，很少 目前存在关于该催化剂的调节的信息， 转录或转录后水平。然而，我们的初步 现在的数据显示，这种酶的表达强烈上升， 在血管平滑肌细胞中转录后调节 转化生长因子-β 1抑制增殖， 通过mRNA衰减速率的显著降低来证明。此外，本发明还提供了一种方法， 主动脉平滑肌中赖氨酰氧化酶启动子构建体的分析 细胞揭示启动子活性显著受血清- 细胞增殖和与B-myb共转染的依赖性变化。 这一重要调控作用的分子基础将被分析 在这个项目中，确定LO mRNA中的顺式元件， 启动子介导这些作用，并表征蛋白质反式- 在每一个扰动下， 条件此外，我们有证据表明，显微镜，免疫化学 和酶的方法，赖氨酰氧化酶是显着定位， 似乎在动脉平滑肌细胞核内起作用。 这一发现的意义将继续下去， 蛋白质底物和由酶在其中产生的产物，以及 评估这种本地化的功能后果， 动脉平滑肌细胞增殖和基因表达。 这些研究将与其他机构密切合作进行。 本计划中的项目是其利益的自然结果 胶原蛋白和弹性蛋白以及B-myb和腺苷配体， 注意到干扰这种酶的表达。