Role of intracellular complement activation in kidney fibrosis

细胞内补体激活在肾纤维化中的作用

• 批准号: 10461113
• 负责人: DIDIER PORTILLA
• 金额: $ 24.23万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-19 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10461113
• 关键词: Affect; Atlases; C3AR1 gene; Cell Survival; Cell physiology; Cells; Chronic Kidney Failure; Cicatrix; Clinical; Clinical Trials; Complement; Complement 5a; Complement Activation; Data; Data Set; Disease; End stage renal failure; Engineering; Epithelial Cells; Fibrosis; Genetic; Health; Inflammatory; Injury; Injury to Kidney; Invaded; Kidney; Kidney Diseases; Ligands; Metabolism; Morbidity - disease rate; Mus; Myeloid Cells; Natural Immunity; Nuclear RNA; Pathogenesis; Pathologic; Pathway interactions; Pericytes; Pharmaceutical Preparations; Phenotype; Physiology; Play; Population; Prevalence; Process; Proteomics; Reagent; Renal function; Risk; Role; Signal Transduction; System; T-Lymphocyte; Testing; Therapeutic; Tubular formation; United States; adaptive immunity; aging population; autocrine; cell type; complement system; cost; glomerulosclerosis; kidney cell; kidney fibrosis; kidney repair; macrophage; mortality; mouse model; nephrogenesis; paracrine; pathogen; receptor; recruit; renal scarring; transcriptome sequencing

PROJECT SUMMARY / ABSTRACT The prevalence of Chronic Kidney Disease (CKD) in the US is high and continues to rise in our aging population. Independent of the cause of CKD, tubulointerstitial fibrosis and glomerulosclerosis represent major pathways of progression of kidney disease, however, there are no approved drugs to treat kidney fibrosis that could ameliorate progression of CKD. In recent studies we demonstrated that locally synthesized and activated kidney complement components drive the pathogenesis of kidney fibrosis. The complement system is of major importance in innate and adaptive immunity, but dysregulated complement has been shown to play a major role in kidney injury. Our pilot data, leveraging single nuclear RNA sequencing (snRNAseq), indicate cell-specific compartmentation of complement components, particularly of C3 and C5 in RTE cells. Our data also indicate that these components ligand their cognate receptors, C3aR and C5aR1, on kidney macrophages in murine models of kidney fibrosis. In preliminary datasets, genetic deletion of these factors in a cell-specific manner imparted significant protection against renal scarring. Thus, the central hypothesis to be tested in this application is that intrinsic expression of complement components from kidney cells, their processing to active fragments and activation of their cognate receptors are key to the progressive loss of kidney function and scaring. This hypothesis will be investigated via the following independent, but complementary, specific aims: Aim 1: Delineate the intracellular expression of complement components by kidney cells. We will use snRNAseq in murine kidney fibrosis to delineate cell type-specific expression of complement components and their receptors. We will confirm data by proteomic approaches and identify the processing machinery generating active secretory fragments from complement components. Aim 2. Determine the importance of RTE-derived C3 for renal physiology and fibrosis. We will use mice engineered to lack C3 specifically in RTE cells to determine the relevance of intracellular complement for renal physiology and injury-induced fibrosis. We will study mice lacking the C3ar1 receptor on either kidney or myeloid cells to establish whether there is an obligate requirement for autocrine or paracrine C3 signaling. Aim 3. Determine the impact of C5a/C5aR1 axis activation on macrophages for the induction of kidney fibrosis or repair. We will validate our preliminary observations that macrophage-specific deletion of C5ar1 reduces fibrosis. We will determine whether C5ar1 directly affects macrophage phenotype and function, or whether C5ar1 macrophages promote scarring by recruiting and activating inflammatory T cells. Collectively, this proposal will establish a comprehensive atlas of complement component expression in kidney cells in healthy and injured kidneys, establish key mechanisms of these pathways in kidney scarring and enable clinical targeting of these pathways with therapeutically relevant strategies.

项目摘要 /摘要 美国慢性肾脏疾病（CKD）的患病率很高，并且在我们的老龄化人群中持续上升。 与CKD的原因无关，微管间质纤维化和肾小球硬化是主要途径 但是，肾脏疾病的进展，没有批准的药物来治疗肾脏纤维化 CKD的改善进展。在最近的研究中，我们证明了本地合成和激活的肾脏 补体成分驱动肾脏纤维化的发病机理。补体系统是主要的 在先天和适应性免疫中的重要性，但已证明补充失调可以发挥主要作用 在肾脏受伤中。我们利用单个核RNA测序（SNRNASEQ）的试验数据表明细胞特异性 补体组件的隔室，特别是RTE细胞中C3和C5的隔室。我们的数据也表明 这些成分配体的同源受体C3AR和C5AR1，在鼠类的肾脏巨噬细胞上 肾纤维化的模型。在初步数据集中，以细胞特异性方式对这些因素的遗传缺失 对肾脏疤痕施加了重大保护。因此，在此应用中要检验的中心假设 是肾细胞的补体成分的内在表达，它们的加工到活性片段 它们的同源受体的激活是肾功能和恐惧的逐渐丧失的关键。这 假设将通过以下独立但互补的特定目的进行研究：目标1：描述 肾细胞补体成分的细胞内表达。我们将在鼠肾中使用snrnaseq 纤维化以描绘补体成分及其受体的细胞类型特异性表达。我们将确认 通过蛋白质组学方法数据并确定从中生成活跃分泌片段的处理机械 补体组件。目标2。确定RTE衍生的C3对肾脏生理和纤维化的重要性。 我们将使用工程设计的小鼠在RTE细胞中专门缺乏C3来确定细胞内的相关性 补充肾脏生理和损伤诱导的纤维化。我们将研究缺乏C3AR1受体的小鼠 肾脏或髓样细胞以确定对自分泌或旁分泌C3是否有义务要求 信号。 AIM 3。确定C5A/C5AR1轴激活对肾脏诱导巨噬细胞的影响 纤维化或修复。我们将验证我们的初步观察，即C5AR1的巨噬细胞特异性缺失 减少纤维化。我们将确定C5AR1是否直接影响巨噬细胞表型和功能，或者 C5AR1巨噬细胞是否通过募集和激活炎症性T细胞来促进疤痕。共同 该提案将建立健康中肾细胞中补体成分表达的全面地图集 和受伤的肾脏，在肾脏疤痕中建立这些途径的关键机制，并实现临床靶向 在这些途径中具有与治疗相关的策略。