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.

摘要 急性肾损伤(AKI)与高发病率和死亡率有关，并显著影响 患者及其家属的生活质量。在美国治疗急性肾脏疾病的费用很高 每年以数百亿美元计。然而，AKI的治疗结果很差，部分原因是 潜在的机制还没有完全弄清楚。缺血/再灌注(IR)是AKI和IS的主要原因 在初始阶段、组织修复阶段和慢性期与炎症有关。然而，这些基因 IR对炎症的调节作用尚未完全明确。近端肾小管对急性肾损伤最敏感。 IR诱导的损伤。Meprs是ASTIN家族中表达最丰富的锌金属蛋白。 近端肾小管刷状缘膜(BBM)中的蛋白质。医疗队由两个人组成 亚基，α和β，形成两种高度相似的蛋白质亚型；Meprin A(α-α亚基或 α-β亚基的杂寡体)和Meprin B(β-β亚基的同质低聚体)。Meprin的中断 基因和给药meprin抑制剂保护小鼠免受IR诱导的AKI，提示meprint s 加重肾脏损伤。MEPRIPs增强IR肾损伤的机制尚不完全 明白了。Meprin蛋白亚型有共同和不同的底物。研究相互作用 MEPRIPs和它们在肾脏中的靶点之间的关系将增加对它们如何影响细胞功能的理解 以及肾脏疾病的病理学。已知的美普林底物包括几种炎症介质，如 促炎症细胞因子如白介素1β、白介素6、白介素18和趋化因子如单核细胞化疗。 引诱蛋白-1(MCP-1)。MEPRINS的蛋白分解处理使IL-6失活，但激活了IL-1β和IL-18。 对meprin在炎症中作用的额外支持来自最近的研究，该研究表明meprinα 介导抗炎肽N-乙酰-丝氨酸-天冬氨酰-赖氨酸(Ac-SDKP)的释放 目前尚不清楚Ac-β的释放是否在调节IR所致的肾损伤中起作用。一个 炎症的长期后果是纤维化，这表明细胞外基质失衡。 (ECM)蛋白质代谢。由于meprint裂解和/或降解几种ECM蛋白(例如Nidogen-1， 层粘连蛋白、纤维连接蛋白和胶原蛋白)，它们可以减轻与IR诱导的肾损伤相关的纤维化。 Meprs还对参与细胞外基质代谢的细胞信号通路中的蛋白质进行蛋白水解性处理。 (例如，蛋白激酶A途径)。MEPRISH的蛋白水解性处理降低了三种蛋白的激酶活性 PKA催化亚基(PKA Cα、Cβ1和Cβ2)的异构体。拟议的研究将利用梅普林 敲除小鼠以确定meprint调节炎症和血管病变进展的机制 IR所致肾损伤的起始期、恢复期和慢性期。这些目标将通过追求实现 三个密切相关的具体目标；(I)确定梅普林亚型如何以及哪些亚型影响炎症 IR所致肾损伤的起始、修复和慢性阶段的反应：(Ii)决定如何 MEPRIPS对PKA催化亚基(PKA C)亚基下游的蛋白水解性加工 PKA信号通路在IR诱导的急性肾损伤中的靶点：(III)确定纤维化相关因素 Megprin活性在IR所致肾损伤中的作用蛋白质组学、实时荧光聚合酶链式反应、Flow 细胞计数和免疫组织化学分析。来自这些研究的数据将增强 了解IR所致肾损伤进展的潜在机制，并告知 开发更有效的治疗方法。