Complement-mediated injury of the kidney: New mechanisms and novel therapies

补体介导的肾脏损伤：新机制和新疗法

• 批准号: 8885494
• 负责人: Joshua M Thurman
• 金额: $ 33.82万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8885494
• 关键词: ANXA2 gene; Acute Renal Failure with Renal Papillary Necrosis; Alternative Complement Pathway; Animal Model; Binding; Biological Markers; Cell surface; Cells; Complement; Complement 3d Receptors; Complement Activation; Complement Factor H; Complement Inactivators; Cyclosporine; Data; Disease; Endothelial Cells; Epithelial Cells; Funding; Gene Deletion; Goals; Grant; Immunosuppressive Agents; In Vitro; Injury; Intrinsic factor; Kidney; Kidney Diseases; Laboratories; Mediating; Methods; Mus; Mutation; Organ; Pathogenesis; Pathway interactions; Patients; Pharmaceutical Preparations; Plasma; Plasma Proteins; Process; Production; Proteins; Public Health; Recombinants; Regulation; Renal Circulation; Research; Resistance; Role; Site; Surface; System; Testing; Therapeutic; Therapeutic Agents; Tissues; Toxic effect; Tubular formation; Work; base; blocking factor; complement pathway; complement system; genetic regulatory protein; glomerular basement membrane; human disease; in vivo; injured; innovation; kidney cell; kidney vascular structure; mesangial cell; novel; novel strategies; novel therapeutic intervention; novel therapeutics; prevent; public health relevance; renal ischemia; research study; treatment strategy

DESCRIPTION (provided by applicant): Recent work has shown that activation of the alternative pathway of complement is central to the pathogenesis of a large number of glomerular and tubulointerstitial renal diseases. It is not known, however, why the kidney is so frequently and uniquely vulnerable to alternative pathway-mediated injury. The central hypothesis of this grant is that the plasma protein factor H is critical for controlling alternativ pathway activation on the glomerular basement membrane and the surface of injured mesangial cells and tubular epithelial cells. Complement regulation within the kidney by factor H is disrupted by the local production of proteins that impair factor H function and by complement-activating microparticles shed by injured cells throughout the body. To test this hypothesis, the following specific aims will be pursued. Aim 1) Determine which regulatory proteins control complement activation in the kidney. The working hypothesis for this aim is that factor H prevents spontaneous complement activation on the GBM and on injured mesangial and tubular epithelial cells. We will use in vitro and in vivo methods to determine which renal surfaces require factor H to prevent complement-mediated injury. We will use targeted complement inhibitors to restore factor H to sites of complement activation within the kidney. Aim 2) Determine how the protein annexin A2 modulates complement regulation by factor H within the kidney. The working hypothesis for this aim is that annexin A2 expressed within the injured kidney blocks factor H function, thus permitting local activation of the alternative pathway. The experiments in this aim will utilize recombinant annexin A2, SiRNA, and mice with targeted deletion of the gene for annexin A2 in order to determine how annexin A2 promotes complement activation on the surface of cells of the kidney in vitro and in vivo. Aim 3) Determine whether plasma microparticles impair complement regulation within the kidney. The working hypothesis of this aim is that microparticles shed from injured endothelial cells cause complement activation within the kidney. These experiments will utilize cyclosporine to generate endothelial microparticles and test whether they cause injury in factor H deficient mice. Cyclosporine-induced microparticles will be injected into factor H deficient mice to determine whether the microparticles directly increase alternative pathway activation and cause renal injury. Finally, we will test whether CR2-factor H, a targeted complement inhibitor, prevents cyclosporine-induced vascular and renal toxicity in factor H deficient mice. The approach outlined above is innovative because it challenges the current understanding of how factor H controls complement activation on tissues and it provides an explanation for why the kidney, among all of the organs, is so uniquely susceptible to alternative pathway-mediated injury. The studies in this grant are significant because they examine a process central to the pathogenesis of a wide range of renal diseases and provide new treatment strategies for these diseases.

描述（由申请人提供）：最近的研究表明，补体旁路途径的激活是大量肾小球和肾小管间质性肾病发病机制的核心。然而，尚不清楚为什么肾脏如此频繁和独特地易受替代途径介导的损伤。这项研究的中心假设是，血浆蛋白因子H对控制肾小球基底膜和受损系膜细胞和肾小管上皮细胞表面的替代途径活化至关重要。通过因子H在肾脏内的补体调节被损害因子H功能的蛋白质的局部产生和通过全身受损细胞脱落的补体活化微粒破坏。为了检验这一假设，将追求以下具体目标。目的1）确定哪些调节蛋白控制肾脏中的补体激活。为此目的的工作假设是，因子H阻止GBM和损伤的系膜和肾小管上皮细胞上的自发补体激活。我们将使用体外和体内方法来确定哪些肾脏表面需要H因子来防止补体介导的损伤。我们将使用靶向补体抑制剂来恢复H因子在肾脏内的补体激活位点。目的2）确定蛋白膜联蛋白A2如何调节肾脏内H因子对补体的调节。这一目标的工作假设是，膜联蛋白A2在受损的肾脏内表达阻断了H因子的功能，从而允许旁路途径的局部激活。该目的的实验将利用重组膜联蛋白A2、SiRNA和靶向缺失膜联蛋白A2基因的小鼠，以确定膜联蛋白A2如何在体外和体内促进肾细胞表面上的补体活化。目的3）确定血浆微粒是否损害肾脏内的补体调节。这一目标的工作假设是，从受伤的内皮细胞脱落的微粒会导致肾脏内的补体激活。这些实验将利用环孢霉素产生内皮微粒，并测试它们是否会导致H因子缺陷小鼠的损伤。将环孢素诱导的微粒注射到因子H缺陷小鼠中，以确定微粒是否直接增加旁路途径激活并引起肾损伤。最后，我们将测试是否CR2-因子H，有针对性的补体抑制剂，防止环孢霉素诱导的血管和肾毒性因子H缺陷小鼠。上面概述的方法是创新的，因为它挑战了目前对因子H如何控制组织上的补体激活的理解，并且它提供了为什么在所有器官中，肾脏如此独特地易受替代途径介导的损伤的解释。这项研究是重要的，因为他们检查了一个过程的核心广泛的肾脏疾病的发病机制，并为这些疾病提供了新的治疗策略。