Pathobiology of Complement C3 effects in ADPKD

ADPKD 中补体 C3 作用的病理学

• 批准号: 8862170
• 负责人: Michal Mrug
• 金额: --
• 依托单位: BIRMINGHAM VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8862170
• 关键词: Address; Adult; Affect; Age; Animal Model; Antigen-Antibody Complex; Attenuated; Autosomal Dominant Polycystic Kidney; Breeding; C3bi; CCL2 gene; CD14 gene; Cell Line; Cell Proliferation; Cell physiology; Cells; Chronic Kidney Failure; Clinical; Complement; Complement 3; Complement Receptor; Cyst; Cystic kidney; DNA; Data; Defect; Diagnosis; Disease; Disease Progression; Drug Targeting; End stage renal failure; Epithelial Cells; Epithelium; Figs - dietary; Foundations; Gap Junctions; Generations; Genetic; Goals; ITGAM gene; Immune; In Vitro; Inherited; Injury; Integrins; Kidney; Kidney Diseases; Knowledge; Link; Macrophage-1 Antigen; Mediating; Messenger RNA; Modeling; Molecular; Mus; Mutation; Outcome; Pathogenesis; Pathway interactions; Patients; Pharmaceutical Preparations; Play; Process; Production; Prognostic Marker; Proteins; Proteomics; Rattus; Reagent; Renal tubule structure; Research Design; Role; SRC gene; Source; Supportive care; TNF gene; Testing; Therapeutic; Tubular formation; Variant; Veterans; advanced disease; base; complement pathway; epigenetic regulation; fluid flow; genetic variant; genome-wide; inhibitor/antagonist; innovation; macrophage; monocyte; novel; novel therapeutics; pre-clinical; protective effect; public health relevance; receptor; response; response to injury; selective expression

DESCRIPTION (provided by applicant): Because the diagnosis of autosomal dominant polycystic kidney disease (ADPKD) cannot be excluded until age 40, many ADPKD patients are veterans. The objective of this proposal is to define therapeutic potential of targeting C3 (the axial component of complement pathway) in ADPKD. In line with paradigm shifts resulting from discoveries of novel essential roles of local C3 production, our studies point to intra-renal production of C3 as a regulator of a pathway that dictates the pace of renal cystogenesis. We formulated this hypothesis based on our genome-wide expression analyses of kidneys with rapid vs slow pace of cystogenesis in a PKD model. We supported this hypothesis by demonstrating: (i) presence of both C3 mRNA and protein in renal tubular cells that line ADPKD and autosomal recessive (AR) PKD cysts and the ability of these cells to activate C3; (ii) increased renal content of biologically active C3 split products i ARPKD and ADPKD and their models; (iii) strong correlation between renal C3 expression and pace of renal cystogenesis in a PKD model and C3 hypoactive gene variant with the disease progression among ADPKD patients; and (iv) significant protective effect of C3 deficiency on renal cystogenesis in genetic PKD models. While C3 may act through different pathways, we have found consistent association of accelerated cystogenesis specifically with the pathway regulated by complement receptor CR3. CR3 (or Mac- 1), a major receptor for C3 fragment iC3b, which is highly abundant in cystic kidneys, plays a central role in differentiation, attachment and survival of monocytes/macrophages. While we have identified C3, macrophage marker CD14 and C3-inducible factor MCP-1 as candidate predictors of PKD outcomes, others have demonstrated that macrophage depletion attenuates cystogenesis in orthologous models of ADPKD by reducing the proliferation of cystic tubules. CR3 may also induce pro-cystogenic TNF release and directly activate c-Src in renal tubule cells. Since renal tubule cells produce and activate C3 when fluid flow is absent we suggest that the C3 effects in PKD increase as cystic tubules dilate, forming a vicious cystogenic cycle. Specifically, we hypothesize that C3 pathway activation accelerates cyst formation in ADPKD through a CR3 dependent process. We address this hypothesis in three inter-related aims: 1) Dissect mechanisms underlying cystogenic effects of C3 production on Pkd1 pathway; 2) Determine effects of renal tubule-derived C3 in the pathogenesis of ADPKD.; and 3) Determine the role of complement component receptor CR3 (or Mac1) in Pkd1-induced cystogenesis. Objectives of these Aims will be accomplished by integrating: (i) highly innovative study design of interrogating novel regulatory mechanisms of renal cystogenesis with (ii) generation of novel state of the art reagents (e.g., for conditional C3 targeting). Achieving the proposed aims will allow integration of existing knowledge by linking established and novel cystogenic pathways to the C3-CR3 nexus. The proposed studies represent the next step for attaining our long-term goal of developing a safe C3-based therapy for ADPKD and other renal disorders.

描述（由申请人提供）： 由于诊断常染色体显性多囊性肾脏疾病（ADPKD）直到40岁才被排除，因此许多ADPKD患者是退伍军人。该建议的目的是定义靶向ADPKD中C3（补体途径的轴向成分）的治疗潜力。与局部C3生产的新基本作用的发现所产生的范式变化一致，我们的研究表明，C3的肾脏产生是决定肾脏囊泡速度的途径的调节剂。我们基于在PKD模型中对肾脏的肾脏和慢速缓慢速度的肾脏的全基因组表达分析提出了这一假设。我们通过证明：（i）在ADPKD和常染色体隐性（AR）PKD囊肿的肾小管细胞中同时存在C3 mRNA和蛋白质，以及这些细胞激活C3的能力； （ii）增加生物活性C3分裂产品I ARPKD和ADPKD及其模型的肾脏含量增加； （iii）PKD模型中肾脏C3表达与肾脏肺结构的速度与ADPKD患者的疾病进展之间的较强相关性； （iv）C3缺乏对遗传PKD模型中肾脏囊肿的显着保护作用。尽管C3可能通过不同的途径起作用，但我们发现加速的胞质发生的稳定关联是专门与补体受体CR3调节的途径。 CR3（或MAC-1）是C3片段IC3B的主要受体，在囊性肾脏中高度丰富，在分化，附着和生存的单核细胞/巨噬细胞中起着核心作用。尽管我们已经确定了C3，巨噬细胞标记CD14和C3诱导因子MCP-1是PKD结果的候选预测指标，但其他人则证明，巨噬细胞的耗竭可通过减少casstic tububules的繁殖而减少ADPKD的正交模型中的囊肿。 CR3还可以诱导促源性TNF释放，并直接激活肾小管细胞中的C-SRC。由于当缺乏流体流动时，肾小管细胞会产生并激活C3，因此我们建议随着囊性小管的扩张，PKD中的C3效应增加，形成恶性的囊肿循环。具体而言，我们假设C3途径激活通过CR3依赖性过程加速了ADPKD中的囊肿形成。我们以三个相互关联的目的解决了这一假设：1）C3产生对PKD1途径的囊性作用的剖析机制； 2）确定肾小管衍生的C3在ADPKD发病机理中的影响； 3）确定补体成分受体CR3（或MAC1）在PKD1诱导的囊肿发生中的作用。这些目标的目标将通过集成来实现：（i）高度创新的研究设计，审问了肾脏囊肿发生的新型调节机制，以及（ii）（ii）新型最先进的试剂（例如，针对有条件的C3靶向）。实现提出的目标将允许通过将已建立和新型的膀胱遗传途径与C3-CR3 Nexus联系起来，从而允许将现有知识整合在一起。拟议的研究代表了我们实现我们长期目标的下一步，即开发针对ADPKD和其他肾脏疾病的安全疗法。