INFLAMM. /APOPTOSIS--EXPERIMENTAL HEMOLYTIC UREMITIC SYN

炎症。

• 批准号: 6871473
• 负责人: BRUCE E. MAGUN
• 金额: $ 22.65万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-03-01 至 2008-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6871473
• 关键词: apoptosis; biological signal transduction; cell type; cysteine endopeptidases; disease /disorder model; enzyme inhibitors; gene expression; gene induction /repression; hemolytic anemia; inflammation; laboratory mouse; lipopolysaccharides; macrophage; microarray technology; polymerase chain reaction; protein biosynthesis; renal failure; renal glomerulus; ricin; shiga toxin

DESCRIPTION (provided by applicant): Hemolytic-uremic syndrome (HUS) is the most common cause of renal failure in children. HUS is a severe inflammatory disease, caused by Shiga toxin-producing E. coli, and is marked by the expression of proinflammatory mediators within the kidneys. Shiga toxin is a member of a large family of ribotoxins whose toxicity to cells stems from the depurination of a single adenine within the "sarcin/ricin" loop of 28S ribosomal RNA (28S rRNA). The depurination of 28S rRNA results not only in the inhibition of protein translation, but also the intense and extended activation of the stress-activated protein kinases such as JNK and p38 MAPK. These kinases are central mediators of inflammatory responses that are responsible for inducing the transcription of proinflammatory cytokines and chemokines. An insufficient understanding of the primary target tissues of Shiga toxins and the mechanisms that drive the proinflammatory and cytotoxic responses has impeded the development of interventional remedies for HUS. The administration of Shiga toxins to experimental animals such as rats and mice has failed to recapitulate the renal hallmarks of HUS that involve glomerular pathologies. We have developed a mouse model of HUS that is induced by administration of ricin, a ribotoxin that has an identical ribosomal target as Shiga toxins, but that binds to receptors present on all cells. We will employ ricin in mice and primary cultured cells (macrophages and cells derived from glomeruli) to elucidate the initial targets of action, the cytotoxic consequences, and the cellular and molecular mechanisms that lead to HUS. I. We will determine the activation of gene expression induced by ricin and LPS in glomeruli in experimental HUS, in wild-type mice and in mice that are deficient in TNF and IL-I receptors: II. We will determine the genes that are activated, and the signaling pathways involved, in cultured cells of the renal glomerulus. III. We will characterize the apoptotic mechanisms in experimental HUS by elucidating the involvement of apical caspase 8 and by determining whether caspase inhibitors can ameliorate the cytotoxic consequences of ricin administration.

描述（由申请人提供）：溶血性尿毒症综合征（HUS）是儿童肾衰竭最常见的原因。溶血性尿毒综合征是一种严重的炎症性疾病，由产志贺毒素的大肠杆菌引起，以肾脏内促炎介质的表达为特征。志贺毒素是一个核糖体毒素大家族的成员，其对细胞的毒性源于28S核糖体RNA （28S rRNA）“sarcin/ricin”环内单个腺嘌呤的去嘌呤化。28S rRNA的去嘌呤化不仅会抑制蛋白质翻译，还会导致应激激活的蛋白激酶如JNK和p38 MAPK的强烈和扩展激活。这些激酶是炎症反应的中心介质，负责诱导促炎细胞因子和趋化因子的转录。对志贺毒素的主要靶组织和驱动促炎和细胞毒性反应的机制了解不足，阻碍了溶血性尿毒综合征介入性治疗的发展。志贺毒素对实验动物（如大鼠和小鼠）的治疗未能重现溶血性尿毒综合征涉及肾小球病理的肾脏特征。我们开发了一种由蓖麻毒素诱导的溶血性尿毒综合征小鼠模型，蓖麻毒素是一种核毒素，与志贺毒素具有相同的核糖体靶点，但与存在于所有细胞上的受体结合。我们将在小鼠和原代培养细胞（巨噬细胞和肾小球细胞）中使用蓖麻毒素来阐明作用的初始靶点、细胞毒性后果以及导致溶血性尿毒综合征的细胞和分子机制。1 .我们将在实验性溶毒症小鼠、野生型小鼠和TNF和il - 1受体缺乏小鼠的肾小球中测定蓖麻毒素和LPS诱导的基因表达激活情况。我们将确定在培养的肾小球细胞中被激活的基因和所涉及的信号通路。3。我们将通过阐明顶端caspase 8的参与以及确定caspase抑制剂是否可以改善蓖麻毒素给药的细胞毒性后果，来表征实验性溶血性毒血症的凋亡机制。