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: 10121560
• 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 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10121560
• 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 慢性肾脏疾病(CKD)在美国的患病率很高，而且在我们老龄化的人口中还在继续上升。 与CKD的病因无关，肾小管间质纤维化和肾小球硬化是CKD的主要途径。 肾脏疾病的进展，然而，还没有被批准的治疗肾脏纤维化的药物可以 改善慢性肾脏病的进展。在最近的研究中，我们证明了局部合成和激活的肾脏 补体成分在肾纤维化发病机制中起主导作用。补语系统是主要的 在先天免疫和获得性免疫中很重要，但补体调节失调已被证明发挥了重要作用 在肾脏损伤方面。我们的试点数据，利用单核RNA测序(SnRNAseq)，表明细胞特异性 RTE细胞中补体成分的区隔，尤其是C3和C5。我们的数据还表明 这些成分与其在小鼠肾巨噬细胞上的同源受体C3aR和C5aR1配基 肾纤维化模型的建立。在初步数据集中，这些因子以细胞特有的方式遗传缺失 对肾脏疤痕有显著的保护作用。因此，在此应用程序中要测试的中心假设 是肾细胞补体成分内在表达，它们被加工成活性片段 而它们的同源受体的激活是肾功能进行性丧失和惊恐的关键。这 将通过以下独立但互补的具体目标来研究假设：目标1：描绘 肾细胞内补体成分的表达。我们将在小鼠肾脏中使用SnRNAseq 纤维化以描述补体成分及其受体的细胞类型特异性表达。我们会确认 通过蛋白质组学方法获得数据，并确定产生活性分泌片段的处理机制 补充成分。目的2.确定RTE来源的C3对肾脏生理和纤维化的重要性。 我们将使用在RTE细胞中特异性缺乏C3的基因工程小鼠来确定细胞内C3的相关性 补充肾脏生理学和损伤诱导的纤维化。我们将研究缺乏C3ar1受体的小鼠 肾脏或髓系细胞以确定是否对自分泌或旁分泌C3有预备性需求 发信号。目的3.确定C5a/C5aR1轴激活对巨噬细胞诱导肾脏的影响 纤维化或修复。我们将验证我们的初步观察结果，即巨噬细胞特异性的C5ar1缺失 减少纤维化。我们将确定C5ar1是否直接影响巨噬细胞的表型和功能，或者 C5ar1巨噬细胞是否通过招募和激活炎性T细胞促进瘢痕形成。总而言之， 这一建议将建立一份全面的补体成分在健康人肾细胞中的表达图谱 和受损的肾脏，建立这些途径在肾脏疤痕形成中的关键机制，并使临床靶向成为可能 这些途径与治疗相关的策略。