MOLECULAR MECHANISMS OF CONTROL OF AORTIC FIBROSIS

细胞外胶原和弹性蛋白纤维的过度沉积 纤维性动脉疾病是闭塞症的主要来源。 血管损伤。赖氨酰氧化酶，催化氧化的酶 赖氨酸以及胶原和弹性蛋白的交联物，起着至关重要的作用， 在这一过程中的控制作用，因此是一个易受攻击的目标 对纤维性动脉疾病的干预。尽管如此，几乎没有 目前，关于这种催化剂的调节信息存在于 转录或转录后水平。然而，我们的初步调查 现在的数据显示，这种酶的表达强烈上调- 在血管平滑肌细胞中的转录后调控 转化生长因子-β1抑制细胞增殖， 信使核糖核酸的衰减率显著降低。此外, 主动脉平滑肌赖氨酰氧化酶启动子结构的分析 细胞显示启动子活性显著受血清- 细胞增殖和与B-myb共转染组的依赖性变化。 这一重要调控效应的分子基础将被分析。 在本项目中，测定了LO中LO mRNA中的顺式元素 启动子介导这些效应，并表征反式- 在每个扰动下与它们具体相互作用的作用因素 条件。另外，我们有显微镜，免疫化学的证据 和酶学方法，赖氨酰氧化酶显著定位和 似乎在动脉平滑肌细胞的细胞核内发挥作用。 这一发现的意义将被追寻，确定核子 蛋白质底物和由酶在其中产生的产物，以及 对本地化的功能后果进行评估 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 在胶原和弹性蛋白以及B-myb和腺苷配体中，我们有 注意到扰乱了这种酶的表达。

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.