Meprin A Metalloproteinase in Acute Kidney Injury

Meprin A 金属蛋白酶在急性肾损伤中的作用

• 批准号: 7781184
• 负责人: Gur Prasad Kaushal
• 金额: $ 25.2万
• 依托单位: UNIV OF ARKANSAS FOR MED SCIS
• 依托单位国家: 美国
• 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/7781184
• 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; 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; Inbred C3H Mice; 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

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）：“ astacin'家族的Meprins，细胞表面和分泌的寡聚金属肽酶，在肾脏近端小管的刷子膜上高度表达。 Meprins在急性肾脏损伤（AKI）中的具体作用尚不完全了解。我们的研究表明，MEPRIN A是大鼠肾脏皮层中的主要基质蛋白酶，能够降解细胞外基质（ECM）蛋白，包括胶原蛋白IV，纤维蛋白，层粘连蛋白，层蛋白和Nidogen。我们最近发表的初步研究表明，Meprins也能够通过其无活性成型和蛋白水解处理化学actactic细胞因子MCP-1产生生物活性的促炎细胞因子白介素1-beta，这表明Meprins在炎症中也很重要。发现从外周血或肾脏组织中分离出的白细胞表达Meprin beta。此外，我们的研究表明，遵循缺血 - 重新灌注和顺铂诱导的Aki，Meprin A被重新分布在近端小管的基底外侧。这些研究表明，在急性管状损伤中，Meprin A在顶端刷子膜以外的其他地方的定位改变可能是有害的。初步研究表明，Meprin脱落可能涉及亚当（崩解蛋白和金属蛋白酶）家族的成员。使用顺铂和缺血再灌注诱导的AKI的体内模型，我们证明了肌动蛋白（Meprin A的有效抑制剂）抑制了Meprin a Intivo a Inty a Inty a In in Bent in Vivo，并减轻急性肾脏损伤和MEPRIN A缺乏小鼠，并且对异倍肽的耐药性具有抗性。有趣的是，我们观察到，在正常小鼠的尿液中无法检测到的Nidogen和Meprin-beta片段在顺铂肾毒性和肌动蛋白期间显着增加，明显阻止了尼多基因片段的尿液排泄。因此，存在一个独特的机会，以进一步探索Meprin A在AKI中的作用和机制。我们假设Meprin A具有巨大的破坏性潜力，由于AKI期间的定位改变而对肾脏近端小管有害，并且了解其作用机理对于保护或减少AKI很重要。我们将通过以下特定目的测试假设：具体目的是：1。使用IR和Cispherplatin肾毒性的实验模型，检查MEPRIN重新分布，肾脏损伤，白细胞浸润和Meprin A脱落之间的时间关系。 2。鉴定IR和顺铂肾毒性期间ECM成分的MEPRIN A介导的体内降解产物。 3.使用MEPRIN抑制剂和Meprin A缺陷小鼠，确定MEPRIN A介导的炎症作用的机制以及Meprin A在AKI期间的功能意义。了解Meprin A在AKI中的潜在作用将为预防急性肾脏损伤的特定治疗干预提供见解。 公共卫生相关性： 肾脏疾病是一种频繁而严重的疾病，影响所有住院患者的5-7％，死亡率高30％的ICU入院，肾衰竭患者的费用估计为每年100亿美元。在发展AKI并随后需要血液透析的患者中，死亡率的风险大于60％。在过去的四十年中，死亡率几乎没有改善。肾脏损伤原因的基础机制仍然很差。本应用中提出的研究直接旨在理解这些机制，这将导致适当的治疗干预措施。