Mechanistic targets for intervention in sepsis-induced renal injury

干预脓毒症肾损伤的机制目标

• 批准号: 8075010
• 负责人: Philip R. Mayeux
• 金额: $ 29.99万
• 依托单位: UNIV OF ARKANSAS FOR MED SCIS
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8075010
• 关键词: 4 year old; Acute Renal Failure with Renal Papillary Necrosis; Address; Adult; Biochemical; Blood Vessels; Blood capillaries; Caspase; Cause of Death; Cell Culture Techniques; Cells; Child; Complication; Data; Defect; Disease; Endothelial Cells; Endothelium; Enzymes; Epithelial; Epithelial Cells; Epithelium; Event; Evolution; Functional disorder; Generations; Genetic; Health; Hour; Immunohistochemistry; Impaired Renal Function; In Vitro; Injury; Intervention; Kidney; Kidney Failure; Knockout Mice; Ligation; Mediating; Mediator of activation protein; Modeling; Motion; Mus; Pathogenesis; Pathway interactions; Patients; Perfusion; Postoperative Period; Protein p53; Puncture procedure; Reactive Nitrogen Species; Reactive Oxygen Species; Relative (related person); Renal function; Research; Role; Scheme; Sepsis; Septicemia; Serum; Signal Pathway; Signal Transduction; Stimulus; Superoxide Dismutase; Techniques; Testing; Tubular formation; Video Microscopy; base; capillary; caspase-3; cell injury; clinically relevant; cost; functional loss; human NOS2A protein; in vivo; inhibitor/antagonist; injured; mortality; new therapeutic target; novel; overexpression; prevent

DESCRIPTION (provided by applicant): Renal failure is a frequent complication of septicemia that contributes significantly to mortality, particularly in postoperative patients in the ICU. In the U.S. septicemia is the 12th leading cause of death in adults and the 9th leading cause of death in children 1-4 years of age. Current therapy is, for the most part, only supportive. Thus, the long-term objective of our research is to identify new therapeutic targets to treat sepsis-induced renal injury. In this proposal, we will describe a functional defect in the kidney that may represent a previously unrecognized vascular pathway involved in polymicrobial sepsis- induced renal injury using the most clinically relevant murine model, cecal ligation and puncture (CLP). Our preliminary data show that inhibition of inducible nitric oxide synthase, inhibition of caspases, or inhibition of p53 each can prevent CLP-induced renal failure in mice. We also discovered a dramatic loss in perfused cortical peritubular capillaries following CLP that is ameliorated by these three classes of inhibitors. This unexpected and novel finding of a CLP-induced vascular defect mediated by reactive nitrogen species (RNS), caspases, and p53 is the basis of our central hypothesis that in sepsis, RNS-initiated activation of caspases results in a decline in peritubular capillary perfusion that leads to RNS-dependent tubular epithelial injury and ultimately renal failure. We will use biochemical and intravital videomicroscopy techniques to assess peritubular capillary dysfunction and tubular injury following mild and severe CLP in mice. Aim 1 will determine if peritubular endothelial injury and capillary dysfunction are early events that precede tubule epithelial cell injury. Aim 2 will determine the relative contributions of caspase-3 and p53 in peritubular capillary dysfunction and tubule epithelial cell injury using both pharmacological and genetic approaches. Aim 3 will determine if RNS-induced activation of p53 and caspases contribute to CLP-induced peritubular capillary dysfunction and tubule epithelial cell injury using pharmacological a genetic approaches. Both Aim 2 and Aim 3 will use in vivo studies as well as complementary in vitro studies with primary cultures of renal endothelial and tubular epithelial cells. PUBLIC HEALTH RELEVANCE: These studies will supply valuable information on the cascade of signaling and cell- specific events that result in sepsis-induced renal injury. They will identify new signaling pathways and test them as new therapeutic targets for this devastating disease.

描述(由申请人提供)：肾功能衰竭是败血症的常见并发症，对死亡率有显著影响，尤其是在ICU的术后患者。在美国，败血症是成人的第12大死因，1-4岁儿童的第9大死因。目前的治疗方法在很大程度上只是支持性的。因此，我们研究的长期目标是寻找新的治疗靶点来治疗脓毒症所致的肾损伤。在这项提案中，我们将使用临床上最相关的小鼠模型盲肠结扎和穿孔(CLP)来描述肾脏的功能缺陷，该缺陷可能代表了一种先前未知的血管通路，参与了多菌败血症引起的肾损伤。我们的初步数据显示，抑制诱导型一氧化氮合酶、抑制caspase或抑制p53均可预防CLP诱导的小鼠肾功能衰竭。我们还发现CLP后灌流的皮质小管周围毛细血管显著减少，这三类抑制剂可以改善这种情况。这一意外而新颖的发现发现了由反应氮物种(RNS)、caspase和p53介导的CLP诱导的血管缺陷，这是我们的中心假设的基础，即在脓毒症中，RNS启动的caspase激活导致肾小管周围毛细血管灌注量下降，从而导致RNS依赖性肾小管上皮损伤，最终导致肾功能衰竭。我们将使用生化和活体视频显微镜技术来评估轻度和重度CLP后小鼠的肾小管周围毛细血管功能障碍和肾小管损伤。目的1将确定肾小管周围内皮细胞损伤和毛细血管功能障碍是否是肾小管上皮细胞损伤之前的早期事件。目的2通过药理学和遗传学方法确定caspase-3和p53在肾小管周围毛细血管功能障碍和肾小管上皮细胞损伤中的相对作用。目的3将通过药物遗传学方法确定RNS诱导的P53和caspase激活是否参与CLP诱导的肾小管周围毛细血管功能障碍和肾小管上皮细胞损伤。AIM 2和AIM 3都将使用体内研究以及与原代培养的肾内皮细胞和肾小管上皮细胞互补的体外研究。公共卫生相关性：这些研究将提供有关导致脓毒症所致肾损伤的一系列信号和细胞特异性事件的有价值的信息。他们将确定新的信号通路，并将其作为这种毁灭性疾病的新治疗目标进行测试。