Meprin A Metalloproteinase in Acute Kidney Injury

Meprin A 金属蛋白酶在急性肾损伤中的作用

基本信息

批准号：
8037765
负责人：
Gur Prasad Kaushal
金额：
$ 20.71万
依托单位：
UNIV OF ARKANSAS FOR MED SCIS
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-03-01 至 2014-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8037765
关键词：
Acute Acute Kidney Failure Acute Renal Failure with Renal Papillary Necrosis Address Adhesions Admission activity Affect Animals Apical Basement membrane Binding Biological Markers Blood Circulation Blood Urea Nitrogen C3H/He Mouse CCL2 gene CD14 gene Cell surface Cells Cisplatin Cleaved cell Collagen Type IV Creatinine Cytoplasm Dialysis procedure Disease Disintegrins Enzymes Epithelial Cells Excretory function Experimental Models Extracellular Matrix Extracellular Matrix Degradation Extracellular Matrix Proteins Family Fibronectins Future Hemodialysis Immunofluorescence Immunologic In Vitro Infiltration Inflammation Inflammatory Inflammatory Response Injury Interleukin-1 beta Interleukins Ischemia Kidney Kidney Diseases Kidney Failure Knockout Mice Laminin Leukocyte Trafficking Leukocytes Light Marrow Mass Spectrum Analysis Mediating Membrane Membrane Proteins Meprin Metalloendopeptidases Metalloproteases Minor Molecular Mouse Strains Movement Mus Na(+)-K(+)-Exchanging ATPase Nephrotoxic Nidogen Patients Peptide Hydrolases Peripheral Postoperative Period Process Proximal Kidney Tubules Publishing Rattus Recombinants Reperfusion Therapy Resistance Risk Risk Factors Role Serum Side Site Specificity Staining method Stains Suggestion T-Lymphocyte Testing Therapeutic Intervention Time Tissues Tubular formation Urine astacin base basolateral membrane brush border membrane chemokine cytokine in vivo in vivo Model inhibitor/antagonist insight kidney cortex macrophage member meprin A migration monocyte mortality mouse model nephrotoxicity overexpression peripheral blood prevent protective effect protein aminoacid sequence public health relevance response response to injury secretase urinary

项目摘要

DESCRIPTION (provided by applicant): Meprins, cell-surface and secreted oligomeric metalloendopeptidases of the 'astacin' family, are highly expressed at the brush-border membranes of the kidney proximal tubules. The specific role of meprins during acute kidney injury (AKI) is not fully understood. Our studies identified that meprin A is the major matrix-degrading protease in the rat kidney cortex capable of degrading the extracellular matrix (ECM) proteins including collagen IV, fibronectin, laminin, and nidogen in vitro. Our recently published and preliminary studies demonstrated that meprins are also capable of producing biologically active proinflammatory cytokine interleukin 1-beta from its inactive proform and proteolytically processing chemotactic cytokine MCP-1, suggesting that meprins are also important in inflammation. Leukocytes isolated from the peripheral blood or the kidney tissue were found to express meprin beta. Furthermore, our studies demonstrate that, following ischemia-reperfusion- and cisplatin-induced AKI, meprin A is redistributed toward the basolateral side of the proximal tubule. These studies suggest that altered localization of meprin A in places other than the apical brush-border membranes may be deleterious in vivo in acute tubular injury. Preliminary studies suggest that meprin A shedding may involve a member of the ADAM (a disintegrin and metalloproteinase) family. Using in vivo models of cisplatin- and ischemia- reperfusion-induced AKI, we demonstrated that actinonin, a potent inhibitor of meprin A inhibits meprin A in vivo and ameliorates acute kidney injury and meprin A-deficient mice are resistant to cisplatin nephrotoxicity. Interestingly, we observed that nidogen and meprin-beta fragments, undetectable in the urine of normal mice, increased significantly during cisplatin nephrotoxicity and actinonin markedly prevented urinary excretion of nidogen fragments. Thus, a unique opportunity exists to further explore the role and mechanism of action of meprin A in AKI. We hypothesize that meprin A, with its enormous destructive potential, is detrimental to renal proximal tubules due to altered localization during AKI and that understanding its mechanism of action is important in protecting or reducing AKI. We will test the hypothesis through the following specific aims: The Specific Aims are: 1. Examine the temporal relationship between meprin A redistribution, renal injury, leukocyte infiltration, and meprin A shedding during AKI using experimental models of IR and cisplatin nephrotoxicity. 2. Identification of meprin A-mediated in vivo degradation products of the ECM components during IR and cisplatin nephrotoxicity. 3. Determine the mechanisms of meprin A-mediated inflammatory effects and functional significance of meprin A during AKI using a meprin inhibitor and meprin A-deficient mice. Understanding the underlying role of meprin A in AKI will provide insights for specific therapeutic interventions to prevent acute kidney injury. PUBLIC HEALTH RELEVANCE: Kidney disease is a frequent and serious disease, which affects 5-7% of all hospitalized patients and 30 % of ICU admissions with a high mortality rate and the expenses related for patients with kidney failure are estimated at $10 billion per year. The risk of mortality is greater than 60% among patients who develop AKI and subsequently require hemodialysis. There has been little improvement in mortality over the last four decades. The mechanisms underlying the causes of kidney injury remain poorly defined. The studies proposed in this application are aimed directly at understanding these mechanisms, which will result in appropriate therapeutic interventions.

描述（由申请人提供）：Meprins、“虾红蛋白”家族的细胞表面和分泌型寡聚金属内肽酶在肾近端小管的刷状缘膜上高度表达。 meprins 在急性肾损伤 (AKI) 期间的具体作用尚不完全清楚。我们的研究发现，meprin A 是大鼠肾皮质中主要的基质降解蛋白酶，能够在体外降解细胞外基质 (ECM) 蛋白，包括 IV 型胶原、纤连蛋白、层粘连蛋白和巢蛋白。我们最近发表的初步研究表明，meprins 还能够从其无活性的原体中产生具有生物活性的促炎细胞因子白细胞介素 1-β，并通过蛋白水解处理趋化细胞因子 MCP-1，这表明 meprins 在炎症中也很重要。发现从外周血或肾组织中分离的白细胞表达meprin beta。此外，我们的研究表明，在缺血再灌注和顺铂诱导的 AKI 后，meprin A 重新分布到近曲小管的基底外侧。这些研究表明，meprin A 在除心尖刷状缘膜以外的地方的定位改变可能在体内急性肾小管损伤中是有害的。初步研究表明 meprin A 脱落可能涉及 ADAM（解整合素和金属蛋白酶）家族的成员。使用顺铂和缺血再灌注诱导的 AKI 体内模型，我们证明了肌动蛋白（meprin A 的有效抑制剂）在体内抑制 meprin A 并改善急性肾损伤，并且 meprin A 缺陷小鼠对顺铂肾毒性具有抵抗力。有趣的是，我们观察到在正常小鼠尿液中检测不到的 nidogen 和 meprin-β 片段在顺铂肾毒性期间显着增加，并且放线菌素显着阻止了 nidogen 片段的尿排泄。因此，存在进一步探索 meprin A 在 AKI 中的作用和作用机制的独特机会。我们假设 meprin A 具有巨大的破坏潜力，由于 AKI 期间定位的改变而对肾近曲小管有害，并且了解其作用机制对于保护或减少 AKI 非常重要。我们将通过以下具体目标检验该假设：具体目标是： 1. 使用 IR 和顺铂肾毒性实验模型检查 AKI 期间 meprin A 重新分布、肾损伤、白细胞浸润和 meprin A 脱落之间的时间关系。 2. IR 和顺铂肾毒性过程中，meprin A 介导的 ECM 成分体内降解产物的鉴定。 3. 使用 meprin 抑制剂和 meprin A 缺陷小鼠确定 AKI 期间 meprin A 介导的炎症效应的机制和 meprin A 的功能意义。了解 meprin A 在 AKI 中的潜在作用将为预防急性肾损伤的具体治疗干预提供见解。公共卫生相关性：肾脏疾病是一种常见且严重的疾病，影响着所有住院患者的 5-7% 和 ICU 入院患者的 30%，死亡率很高，每年与肾衰竭患者相关的费用估计为 100 亿美元。发生 AKI 并随后需要血液透析的患者的死亡风险高于 60%。过去四十年来，死亡率几乎没有改善。肾损伤的潜在机制仍不清楚。本申请中提出的研究直接旨在了解这些机制，这将导致适当的治疗干预措施。