LOCAL EXPRESSION OF ALPHA-1-ANTITRYPSIN IN EMPHYSEMA

肺气肿中 ALPHA-1-抗胰蛋白酶的局部表达

基本信息

批准号：
3353772
负责人：
David H Perlmutter
金额：
$ 14.34万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1986
资助国家：
美国
起止时间：
1986-09-01 至 1994-08-31
项目状态：
已结题

项目摘要

Homozygous PiZZ alpha 1 proteinase inhibitor deficiency is associated with premature development of pulmonary emphysema and is the most common metabolic cause of liver disease in children. This deficiency probably results from an abnormally folded protein which is unable to efficiently traverse the secretory pathway and accumulates inside the cell. Thus, the net intracellular accumulation of alpha 1 PI in cells of deficient (PiZZ) individuals depends on a delicate balance between its synthesis, entry into and transport within the secretory pathway, and intracellular degradation. Recent studies in model experimental systems indicate that specific protein-protein interactions, involving proteins of the heat shock/stress family, are responsible for entry into the secretory pathway, for traversing the secretory pathway and for solubilization or degradation within this pathway. In work over the last 2 years, supported by this award, we have identified several different mechanisms for regulation of the synthesis of alpha 1 PI. In each case, when synthesis of alpha 1 PI increases, there is greater intracellular accumulation of the mutant protein in deficient cells. Preliminary experiments now indicate that the mutant alpha 1 PI protein binds inside the cell to a protein of the heat shock/stress family. Furthermore, there is a marked increase in synthesis of stress proteins in cells of deficient individuals. This increase in synthesis of stress proteins especially affects deficient individuals with liver disease as contrasted to those with lung disease or those without tissue injury. In this renewal application we will further define mechanisms by which synthesis of alpha 1 PI is regulated and initiate studies of the transport and degradation of alpha 1 PI. More specifically, we will characterize the novel mechanism by which elastase regulates the synthesis of its inhibitor, alpha 1 PI. Specific protein-protein interactions between mutant alpha 1 PI and proteins of the heat shock/stress family will be examined. Proteolytic systems responsible for intracellular degradation of alpha 1 PI will be identified in cell lines transfected with normal, mutant PiS and mutant PiZ alpha 1 PI alleles. finally, EBV-transformed B-Lymphocyte cell lines and skin fibroblasts from deficient individuals with each clinical phenotype will be transfected with the normal or mutant alpha 1 PI genes to determine whether there are differences in transport and degradation of mutant alpha 1 PI in deficient individuals with liver disease as contrasted with those having lung disease or those having no apparent tissue injury. These studies have broad application to the understanding of this common genetic deficiency, consequent injury to lung and liver and to the development of new therapeutic strategies.

纯合 PiZZ α 1 蛋白酶抑制剂缺陷与肺气肿过早发展，是最常见的儿童肝病的代谢原因。这个不足大概由异常折叠的蛋白质导致，无法有效地穿过分泌途径并在细胞内积累。因此，缺陷细胞 (PiZZ) 中 α1 PI 的细胞内净积累个体依赖于其合成、进入之间的微妙平衡分泌途径内的运输和细胞内降解。最近对模型实验系统的研究表明，特定的蛋白质-蛋白质相互作用，涉及热休克/应激的蛋白质家族，负责进入分泌途径，穿过分泌途径并进行溶解或降解在此途径内。在过去两年的工作中，在该奖项的支持下，我们确定了调节 alpha 1 PI 合成的几种不同机制。在每种情况下，当 alpha 1 PI 的合成增加时，缺陷细胞中突变蛋白在细胞内积累。现在初步实验表明突变的α1 PI蛋白在细胞内与热休克/应激家族的蛋白质结合。此外，应激蛋白的合成显着增加。有缺陷的个体的细胞。这种压力合成的增加蛋白质缺乏尤其影响患有肝病的个体，例如与那些患有肺部疾病或没有组织损伤的人形成对比。在此续订申请中，我们将进一步定义机制 α1 PI 的合成受到调节并启动转运研究和α1PI的降解。更具体地说，我们将描述弹性蛋白酶调节其抑制剂合成的新机制，阿尔法 1 PI。突变体α1之间的特定蛋白质-蛋白质相互作用将检查 PI 和热休克/应激家族的蛋白质。负责 α1 PI 细胞内降解的蛋白水解系统将在转染正常、突变 PiS 和突变型 PiZ alpha 1 PI 等位基因。最后，EBV转化的B淋巴细胞每个临床缺陷个体的纹路和皮肤成纤维细胞表型将用正常或突变的 alpha 1 PI 基因转染确定运输和降解是否存在差异与对照相比，患有肝病的缺陷个体中存在突变型 α1 PI 患有肺部疾病或没有明显组织损伤的人。这些研究对于理解这一常见问题具有广泛的应用遗传缺陷，随之而来的肺和肝损伤开发新的治疗策略。