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.

胶原蛋白和弹性蛋白的细胞外纤维的过量沉积 纤维化动脉疾病是闭塞质量的主要来源 血管病变。赖氨酸氧化酶，催化氧化的酶 赖氨酸和胶原蛋白和弹性蛋白的交叉连接，发挥着关键的作用 在此过程中控制角色，因此是脆弱的目标 干预纤维化动脉疾病。但是，很少 目前存在有关调节该催化剂的信息 转录或转录后水平。但是，我们的初步 现在的数据显示，该酶的表达强烈上升 - 在转录后的血管平滑肌细胞中调节 水平作为增殖，通过转化生长因子-beta1抑制了水平， mRNA衰减速率显着降低，证明了。此外， 主动脉平滑肌中赖氨酸氧化酶启动子构建体的分析 细胞揭示启动子活性受血清的显着影响 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效应的分子碱基 在该项目中，确定LO中LO mRNA中的顺式元素 介导这些作用的启动子，并表征蛋白质反式 在每个扰动下都特别与之相互作用的作用因素 健康）状况。此外，我们有微观，免疫化学的证据 以及酶促方法，赖氨酸氧化酶是显着局部的，并且 似乎在动脉平滑肌细胞的核中起作用。 这一发现的意义将被追求，确定核 蛋白质底物和产物由酶产生的蛋白质和产物， 评估此本地化在 动脉平滑肌细胞的增殖和基因表达。 这些研究将与其他 该计划中的项目是其利益的自然结果 在胶原蛋白和弹性蛋白以及B-Myb和腺苷配体中 注意到这种酶的表达。