Meprin Metalloproteases in Kidney Injury

Meprin 金属蛋白酶在肾损伤中的作用

• 批准号: 9751895
• 负责人: Elimelda Moige Ongeri
• 金额: $ 36万
• 依托单位: NORTH CAROLINA AGRI & TECH ST UNIV
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-18 至 2021-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9751895
• 关键词: Acute; Acute Renal Failure with Renal Papillary Necrosis; Affect; Anti-inflammatory; Antibodies; CCL2 gene; Catalytic Domain; Cell Line; Cell Survival; Cell physiology; Chronic; Chronic Phase; Cleaved cell; Collagen; Complementary DNA; Confocal Microscopy; Cyclic AMP-Dependent Protein Kinases; Data; Development; Distal; Enzymes; Expression Profiling; Extracellular Matrix; Extracellular Matrix Proteins; Family; Fibronectins; Fibrosis; Flow Cytometry; Genes; Genotype; Goals; Harvest; Hypoxia; In Vitro; Individual; Infiltration; Inflammation; Inflammation Mediators; Inflammatory Response; Injury; Intensive Care Units; Interleukin-1 beta; Interleukin-18; Interleukin-6; Interleukins; Ischemia; Kidney; Kidney Diseases; Knockout Mice; Knowledge; Laminin; Leukocytes; Mass Spectrum Analysis; Mediating; Meprin; Metabolism; Metalloproteases; Morbidity - disease rate; Mus; Pathology; Pathway interactions; Patients; Peptides; Phase; Phenotype; Phosphorylation; Phosphotransferases; Play; Process; Protein Isoforms; Proteins; Proteolytic Processing; Proteomics; Proximal Kidney Tubules; Quality of life; Reperfusion Injury; Reperfusion Therapy; Role; Running; Signal Pathway; Signal Transduction; Signaling Protein; Site; Time; Tissues; Treatment outcome; United States; Wild Type Mouse; Work; Zinc; brush border membrane; chemokine; cost; cytokine; differential expression; dimer; effective therapy; experimental study; in vivo; inflammatory marker; inhibitor/antagonist; kidney cell; lysylproline; mortality; nidogen-1; protein metabolism; public health relevance; receptor; renal ischemia; response; therapy development; thymosin beta(4); tissue repair; urinary

ABSTRACT Acute kidney injury (AKI) is associated with high morbidity and mortality rates, and significantly impacts the quality of life for patients and their families. The cost of treating acute kidney disease in the United States runs in the tens of billions of dollars annually. However, treatment outcomes for AKI are poor in part because underlying mechanisms are not fully understood. Ischemia/reperfusion (IR) is the leading cause of AKI and is associated with inflammation in the initiation, tissue repair, and chronic phases. However, the genes which modulate inflammation in IR are not fully defined. The proximal kidney tubules are the most susceptible to AKI IR-induced injury. Meprins, zinc metalloproteases of the astacin family, are the most abundantly expressed proteins in the brush border membranes (BBMs) of proximal kidney tubules. Meprins are made up of two subunits, α and β, which form two highly similar protein isoforms; meprin A (a homooligomer of α-α subunits or a heterooligomer of α-β subunits) and meprin B (a homooligomer of β-β subunits). Disruption of the meprin genes and administration meprin inhibitors protect mice from IR-induced AKI, suggesting that meprins exacerbate kidney injury. The mechanisms by which meprins enhance IR-induced kidney injury are not fully understood. The meprin protein isoforms have common and distinct substrates. Studying the interactions between meprins and their targets in the kidney will increase understanding of how they impact cell function and the pathology of kidney disease. Known meprin substrates include several mediators of inflammation such as (i) proinflammatory cytokines e.g. interleukins (IL-1β, IL-6, IL-18) and chemokines e.g. monocyte chemo- attractant protein-1 (MCP-1). Proteolytic processing by meprins inactivates IL-6, but activates IL-1β and IL-18. Additional support for a role for meprins in inflammation came from recent studies demonstrating that meprin α mediates the release of the anti-inflammatory peptide N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) from thymosin β4. It is not known if the Ac-SDKP release plays a role in modulating IR-induced kidney injury. A long-term consequence of inflammation is fibrosis, suggesting that there is an imbalance in extracellular matrix (ECM) protein metabolism. Since meprins cleave and/or degrade several ECM proteins (e.g. nidogen-1, laminin, fibronectin, and collagen), they could alleviate the fibrosis associated with IR-induced kidney injury. Meprins also proteolytically process proteins that mediate cell signaling pathways involved in ECM metabolism (e.g. the protein kinase A pathway). Proteolytic processing by meprins reduces the kinase activity of three isoforms of the catalytic subunit of PKA (PKA Cα, Cβ1, and Cβ2). The proposed studies will utilize meprin knock out mice to determine the mechanisms by which meprins modulate inflammation and the progression of IR-induced renal injury in the initiation, reparative, and chronic phases. The goals will be achieved by pursuing three closely related specific aims; (i) determine how and which meprin isoforms impact the inflammatory response in the initiation, reparative, and chronic phases of IR-induced kidney injury, (ii) determine how proteolytic processing of isoforms of the catalytic subunit of PKA (PKA C) by meprins impacts downstream targets of the PKA signaling pathway in IR-induced acute kidney injury, (iii) determine fibrosis-associated genes impacted by meprin activity in IR-induced renal injury. A combination of proteomics, real-time PCR, flow cytometry, and immunohistochemical analysis will be used. Data from these studies will enhance understanding of the mechanisms underlying the progression of IR-induced kidney injury and inform the development of more effective therapies.

抽象的 急性肾损伤（AKI）与高发病率和死亡率相关，并显着影响 在美国，治疗急性肾病的费用很高。 然而，AKI 的治疗效果不佳，部分原因是每年数百亿美元。 缺血/再灌注 (IR) 是 AKI 的主要原因，其潜在机制尚不完全清楚。 然而，与炎症起始、组织修复和慢性阶段相关的基因。 IR 中调节炎症的机制尚未完全确定。近端肾小管最容易受到 AKI 的影响。 IR 诱导的损伤。Meprins 是虾蛋白家族的锌金属蛋白酶，表达最丰富。 近端肾小管刷状缘膜 (BBM) 中的蛋白质由两种 Meprins 组成。 亚基 α 和 β，形成两种高度相似的蛋白质亚型（meprin A）（α-α 亚基的同源寡聚物或 α-β 亚基的异寡聚物）和 meprin B（β-β 亚基的同寡聚物）。 基因和给药 meprin 抑制剂可保护小鼠免受 IR 诱导的 AKI，这表明 meprins 加剧肾损伤。 meprins 增强 IR 诱导的肾损伤的机制尚不完全清楚。 研究了 meprin 蛋白亚型具有共同且不同的底物。 meprins 及其肾脏靶标之间的关系将增加人们对它们如何影响细胞功能的了解 和肾脏疾病的病理学已知的 meprin 底物包括几种炎症介质，例如 (i) 促炎细胞因子，例如白细胞介素（IL-1β、IL-6、IL-18）和趋化因子，例如单核细胞趋化因子 meprins 的蛋白水解作用使 IL-6 失活，但激活 IL-1β 和 IL-18。 最近的研究表明 meprin α 在炎症中发挥作用，这进一步支持了 meprin α 介导抗炎肽 N-乙酰基-丝氨酰-天冬氨酰-赖氨酰-脯氨酸 (Ac-SDKP) 的释放 尚不清楚 Ac-SDKP 释放是否在调节 IR 诱导的肾损伤中发挥作用。 炎症的长期后果是纤维化，表明细胞外基质不平衡 (ECM) 蛋白质代谢。由于 meprins 会裂解和/或降解多种 ECM 蛋白质（例如 nidogen-1、 层粘连蛋白、纤连蛋白和胶原蛋白），它们可以减轻与红外线诱导的肾损伤相关的纤维化。 Meprins 还可以蛋白水解过程介导参与 ECM 代谢的细胞信号传导途径的蛋白质 （例如蛋白激酶 A 途径）。meprins 的蛋白水解过程会降低三种激酶的活性。 PKA 催化亚基的亚型（PKA Cα、Cβ1 和 Cβ2）。拟议的研究将利用 meprin。 敲除小鼠以确定 meprins 调节炎症和进展的机制 IR 引起的肾损伤的起始阶段、修复阶段和慢性阶段将通过追求来实现。 三个密切相关的具体目标；（i）确定 meprin 异构体如何以及哪些影响炎症 IR 引起的肾损伤的起始阶段、修复阶段和慢性阶段的反应，(ii) 确定如何 meprins 对 PKA 催化亚基 (PKA C) 亚型的蛋白水解加工影响下游 IR 诱导的急性肾损伤中 PKA 信号通路的靶标，(iii) 确定与纤维化相关的 IR 诱导的肾损伤中受 meprin 活性影响的基因 蛋白质组学、实时 PCR、流式细胞术的组合。 将使用细胞计数和免疫组织化学分析来增强这些研究的数据。 了解 IR 诱导的肾损伤进展的机制并告知 开发更有效的疗法。