AATF and Renal Protection

AATF 和肾脏保护

• 批准号: 8021029
• 负责人: QING GUO
• 金额: $ 27.46万
• 依托单位: UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2013-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8021029
• 关键词: 1-Phosphatidylinositol 3-Kinase; 12q21; 17q11.2-q12; Abbreviations; Acute Kidney Failure; Affinity; Amino Acid Sequence; Amino Acids; Apoptosis; Apoptosis Regulator; Apoptotic; BCL2 gene; Binding; Biochemical Markers; Biological; Blood flow; Calcium; Caspase; Cell Death; Cell Survival; Cell physiology; Cells; Cessation of life; Chemicals; Chromosomes; Clinical; Complex; DAP kinase; DNA; Data; Death Domain; Dependovirus; Dominant-Negative Mutation; Elements; Epithelial Cells; Etiology; Event; Exhibits; Family; Free Radicals; Gene Expression; Gene Transfer; Genes; Genetic; Genetic Transcription; Glucose; Growth Factor; Health; Homologous Gene; Hormones; Human; Human Chromosomes; Inflammatory Response; Injury; Ischemia; Kidney; Laboratories; Lead; Left; Length; Leucine Zippers; Lipid Peroxidation; Malignant Neoplasms; Mammals; Maps; Mediating; Metabolism; Methods; Mitochondria; Modeling; Molecular; Molecular Structure; Morbidity - disease rate; Mus; Necrosis; Neurons; Nuclear; Nuclear Localization Signal; Nuclear Translocation; Open Reading Frames; Organ; Oxidative Stress; Oxygen; PAWR gene; PAWR protein; Parvovirus; Pathogenesis; Pathway interactions; Peptide Sequence Determination; Peroxonitrite; Phosphorylation; Phosphorylation Site; Phosphotransferases; Play; Production; Prostate; Protein Isoforms; Protein Kinase; Protein-Serine-Threonine Kinases; Proteins; Proximal Kidney Tubules; Publishing; RNA Interference; Rattus; Recombinant adeno-associated virus (rAAV); Regulation; Renal tubule structure; Reperfusion Injury; Reperfusion Therapy; Research; Role; Signal Transduction; Stimulus; Superoxides; Testing; Therapeutic; Therapeutic Intervention; Tissues; Toxic effect; Transcription factor genes; Transcriptional Activation; Tubular formation; Viral Oncogene; Virion; Virus; adeno-associated viral vector; base; caspase-3; cytokine; effective therapy; falls; genetic manipulation; human STK6 protein; in vitro Model; in vivo; interdisciplinary approach; member; mitochondrial dysfunction; mortality; novel; novel therapeutics; overexpression; prevent; pro-apoptotic protein; renal ischemia; response; restoration; targeted delivery; transcription factor; transgene expression; vector

DESCRIPTION (provided by applicant): Renal tubule epithelial cells are particularly vulnerable to ischemia/reperfusion (I/R)-induced injury. I/R is the most common cause of acute renal failure, a major clinical problem with exceptionally high morbidity and mortality. Although both apoptotic and necrotic cell death contribute renal I/R injury, effective treatment for this devastating condition is lacking. We have recently found that AATF (apoptosis antagonizing transcription factor) is expressed in renal proximal tubule cells wherein it plays a crucial role in inhibiting cell-death pathways in well-characterized models of renal I/R. Increased expression of AATF significantly ameliorated, while silencing of AATF by RNA interference (RNAi) exacerbated apoptotic and necrotic cell death following I/R in renal tubule epithelial cells. Preliminary studies indicates that AATF interacts with the proapoptotic protein Par-4 (prostate apoptosis response-4), and blocks cell death pathways initiated by Par-4 in renal tubule epithelial cells. Of importance, Par4-dependent cell death seems to be mediated by nuclear translocation and suppression of bcl-2 transcription. In addition, we found that AATF was novel phosphorylation substrate of Akt1, a protein kinase and an important downstream target of phosphatidylinositol 3-kinase. These findings open the exciting possibility that AATF represents a Par4- interacting, Akt1-regulated pathway that plays a critical role in controlling renal damage following I/R. We propose three specific aims to investigate this novel mechanism of renal protection: (1) to determine if AATF plays a critical role in protection of renal tubule epithelial cells, and if targeted delivery of AATF in the kidney using recombinant adeno-associated virus (AAV)-based vectors can be used as a potential therapeutic approach for I/R-induced renal injury in vivo; (2) to investigate the molecular mechanisms of Par4-mediaited renal toxicity and to study how transcriptional activation of the anti-apoptotic gene bcl-2 is regulated by AATF/Par-4 complex formation; and (3) to examine if binding and phosphorylation of AATF by Akt1 represents a novel regulatory mechanism underlying the renoprotective actions of AATF following I/R. Targeted delivery of AATF in the kidney by pharmacological and/or genetic manipulations may provide novel therapeutic applications for ischemia-reperfusion induced renal injury. PUBLIC HEALTH RELEVANCE Ischemia/reperfusion-induced renal injury (IRI) is the most common cause of acute renal failure, a major clinical problem with exceptionally high morbidity and mortality. Our preliminary studies suggest that AATF (apoptosis antagonizing transcription factor) is expressed in renal proximal tubule cells wherein it may play a crucial role in protecting against IRI. This project will use multidisciplinary approaches to examine the mechanisms underlying the renal protective actions of AATF at cellular and molecular levels, and to determine if pharmacological and/or genetic manipulations of renal AATF may provide new therapeutic applications for IRI.

描述（由申请人提供）：肾小管上皮细胞特别容易受到缺血/再灌注（I/R）诱导的损伤。 I/R 是急性肾衰竭的最常见原因，这是一个发病率和死亡率极高的主要临床问题。尽管细胞凋亡和坏死性细胞死亡都会导致肾缺血再灌注损伤，但目前仍缺乏针对这种破坏性病症的有效治疗方法。我们最近发现AATF（凋亡拮抗转录因子）在肾近曲小管细胞中表达，在肾缺血再灌注模型中，它在抑制细胞死亡途径中发挥着至关重要的作用。 AATF 表达的增加显着改善，而 RNA 干扰 (RNAi) 沉默 AATF 则加剧了肾小管上皮细胞 I/R 后的细胞凋亡和坏死。初步研究表明，AATF 与促凋亡蛋白 Par-4（前列腺凋亡反应 4）相互作用，阻断肾小管上皮细胞中 Par-4 启动的细胞死亡途径。重要的是，Par4 依赖性细胞死亡似乎是由核易位和 bcl-2 转录抑制介导的。此外，我们发现AATF是Akt1的新型磷酸化底物，Akt1是一种蛋白激酶，也是磷脂酰肌醇3激酶的重要下游靶标。这些发现开启了令人兴奋的可能性，即 AATF 代表 Par4- Akt1 调节的相互作用通路在控制 I/R 后的肾损伤中发挥着关键作用。我们提出了三个具体目标来研究这种新的肾脏保护机制：（1）确定AATF是否在保护肾小管上皮细胞中发挥关键作用，以及使用基于重组腺相关病毒（AAV）的载体在肾脏中靶向递送AATF是否可以作为体内缺血再灌注引起的肾损伤的潜在治疗方法； (2) 探讨Par4介导的肾毒性的分子机制，并研究AATF/Par-4复合物的形成如何调控抗凋亡基因bcl-2的转录激活； (3) 检查 Akt1 对 AATF 的结合和磷酸化是否代表了 I/R 后 AATF 肾脏保护作用的一种新的调节机制。通过药理学和/或基因操作将AATF靶向递送到肾脏中可能为缺血再灌注引起的肾损伤提供新的治疗应用。公众健康相关性 缺血/再灌注引起的肾损伤 (IRI) 是急性肾衰竭的最常见原因，这是一个发病率和死亡率极高的主要临床问题。我们的初步研究表明，AATF（凋亡拮抗转录因子）在肾近曲小管细胞中表达，其中它可能在预防 IRI 中发挥关键作用。该项目将采用多学科方法在细胞和分子水平上研究 AATF 肾脏保护作用的机制，并确定肾脏 AATF 的药理学和/或基因操作是否可以为 IRI 提供新的治疗应用。