Mechanisms of end organ damage in novel polygenic lupus models

新型多基因狼疮模型的终末器官损伤机制

• 批准号: 10007264
• 负责人: Keith B. Elkon
• 金额: $ 40.48万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-09 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10007264
• 关键词: Address; Anti-inflammatory; Antibodies; Antigen-Antibody Complex; Apoptotic; Autoantibodies; B-Lymphocytes; Blood Circulation; Cause of Death; Cells; Chromatin; Chronic; Clinical; Complement; Complement 1q; Complement 3 Convertase; Complement Activation; Complement Membrane Attack Complex; DNA; Data; Defect; Deposition; Disease; Effector Cell; Exhibits; Fibrin; Fibrosis; Functional disorder; Genes; Genetic; Goals; Human; Human Characteristics; Immune; Immunoglobulin G; Immunological Models; Impairment; In Situ Nick-End Labeling; Inflammation; Inflammatory; Injury; Interferon Type I; Interferons; Kidney; Kidney Diseases; Knock-out; Knockout Mice; Lead; Lectin; Light; Lupus; Lupus Nephritis; Mediating; Mitochondria; Modeling; Molecular; Mouse Strains; Mus; Mutant Strains Mice; Myeloid Cells; Nephritis; Opsonin; Organ; Oxides; Pathogenesis; Pathogenicity; Pathway interactions; Patients; Pilot Projects; Play; Predisposition; Process; Recombinants; Renal function; Research; Resolution; Role; SLEB1 gene; Skin; Skin injury; Stains; Systemic Lupus Erythematosus; Systemic disease; Testing; Therapeutic; Thrombin; Tissues; Transplantation; UV Radiation Exposure; Ultraviolet B Radiation; Ultraviolet Rays; base; complement pathway; experimental study; extracellular; genetic signature; inhibitor/antagonist; insight; interest; kidney biopsy; macrophage; monocyte; mortality; mouse model; mutant; nephrotoxicity; neutrophil; novel; prevent; protein complex; reconstitution; renal damage; skin disorder; skin lesion; targeted treatment; therapy design; trafficking; ultraviolet

Project Summary The major cause of death in systemic lupus erythematosus (SLE) is lupus nephritis (LN) but the mechanisms responsible for kidney damage remain only partly understood. A limitation of current mouse models of LN is that genetic causes are incompletely understood or they are single gene models that don’t reflect the polygenic nature of human SLE. To generate a polygenic mouse model with immune pathway abnormalities that are known to underlie SLE, we generated mice with defects in apoptotic cell (AC) clearance (lack MFG-E8), have low complement (C1q or C3 KO) and that produce anti-chromatin antibodies (have Sle1 interval). We observed that, only when all three components are present together (triple mutants, TM) do mice get LN. Of great interest, the C3 deficient TM was sensitive to UV light and developed chronic skin disease and systemic manifestations following UV exposure. The long-term goals of this project are: to understand the protective role of the AC opsonin, MFG-E8, in the kidney; to explore the protective roles of complement in the kidney under conditions of nephritogenic antibodies and impaired AC clearance; to identify the effector mechanisms of kidney injury in TM mice and the mechanisms responsible for UV mediated kidney disease. In Aim 1, we will determine whether AC and inflammation are increased in the kidneys of double versus single KO mice. We will also test whether MFG-E8 has anti-inflammatory and anti-fibrotic effects in the kidney by reconstituting mice with MFG-E8 or MFG-E8 conditioned macrophages. In Aim 2, we will determine the effector mechanisms responsible for kidney injury. Based on preliminary data, we will confirm that in low C1q states the lectin pathway is activated by DAMPS and will attempt to prove lectin pathway pathogenicity by blocking Masp- 2. In low C3 states where we observed C5-9 formation, we will test whether an alternate C5 convertase is generated by thrombin and will attempt to prove pathogenicity by inhibition experiments. These pathways will be validated using uniform nephrotoxic sera in mice deficient in Mfge8, C1q, C3 or double knock outs (DKO) and pilot studies will be performed in kidneys from SLE patients with persistently low complement. Aim 3 takes advantage of the observation that UV light exposure of skin in C3 TM mice leads to systemic disease. We will examine whether this susceptibility is explained by release of oxidized mitochondrial DNA from neutrophils and/ or by trafficking of inflammatory cells from skin to kidney, including by the process of reverse transmigration. Overall, using novel strains that accurately reflect pathway abnormalities in human SLE, we will determine whether and how early complement components as well as an opsonin such as MFG-E8, protect the kidneys. The involvement of the lectin pathway or thrombin have important therapeutic implications as therapies to block each of these pathways either are, or can be used, in humans. Identification of the mechanisms responsible for UV triggered kidney injury will also lead to therapeutic approaches such as inhibition of mitochondrial ROS or inhibitors of cGAS-STING or inhibitors of neutrophil reverse transmigration.

项目摘要 全身性红斑狼疮（SLE）的主要死亡原因是狼疮肾炎（LN），但机制 负责肾脏损伤的原因只有部分理解。当前LN鼠标模型的局限性是 遗传原因未完全理解，或者它们是单一基因模型，不反映多基因性质 人类sle。生成具有免疫途径异常的多基因小鼠模型，已知 基础SLE，我们在凋亡细胞（AC）清除率（缺乏MFG-E8）中产生了缺陷的小鼠，较低 完成（C1Q或C3 KO）并产生抗染色质抗体（具有SLE1间隔）。我们观察到， 只有当所有三个组件都存在（三重突变体，TM）时，小鼠才能获得LN。非常感兴趣的 C3缺乏TM对紫外线敏感，并发展出慢性皮肤疾病和全身表现 在紫外线曝光之后。该项目的长期目标是：了解AC的受保护作用 Opsonin，MFG-E8，在肾脏中；探索在肾脏在肾脏中的保护作用 肾脏生成抗体和AC清除受损；确定TM肾损伤的效应器机制 小鼠和负责紫外线介导的肾脏疾病的机制。 在AIM 1中，我们将确定Double与单个的肾脏中的交流和炎症是否增加 KO老鼠。我们还将测试MFG-E8是否通过 用MFG-E8或MFG-E8条件巨噬细胞重建小鼠。在AIM 2中，我们将确定效应器 导致肾脏损伤的机制。根据初步数据，我们将确认在低C1Q中指出 凝集素途径被潮湿激活，并将试图通过阻止MASP-来证明凝集素途径的致病性。 2。在我们观察到C5-9形成的低C3状态下，我们将测试替代C5转化酶是否为 由凝血酶产生，并将试图通过抑制实验证明致病性。这些途径将是 在缺乏MFGE8，C1Q，C3或Double敲门效果（DKO）的小鼠中，使用均匀的肾毒性血清（DKO）验证 试点研究将在持续较低完成的SLE患者的肾脏中进行。 AIM 3带 观察到C3 TM小鼠皮肤的光照暴露的优势导致全身性疾病。我们将 检查是否通过释放中性粒细胞和/////////////////////////// ofer// ofer//////释放氧化的线粒体DNA来解释这种敏感性。 或通过从皮肤到肾脏的炎症细胞进行运输，包括通过反向传播的过程。 总体而言，使用精确反映人SLE途径异常的新型菌株，我们将确定 是否以及如何提早完成组件以及诸如MFG-E8之类的副本蛋白保护孩子们。 讲座途径或凝血酶的参与具有重要的治疗意义，以阻止 这些途径中的每一个要么在人类中使用或可以使用。识别负责的机制 紫外线触发的肾脏损伤还将导致治疗方法，例如抑制线粒体ROS或 CGAS刺激或中性粒细胞反向传播的抑制剂的抑制剂。