The role of human SLE causal variant NCF1.pR90H in promoting kidney damage

人类SLE致病变异NCF1.pR90H在促进肾脏损伤中的作用

基本信息

批准号：
10740630
负责人：
BETTY P TSAO
金额：
$ 36.54万
依托单位：
MEDICAL UNIVERSITY OF SOUTH CAROLINA
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-09-23 至 2025-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10740630
关键词：
ALCAM gene Acceleration Affect African American Age American Antigen-Antibody Complex Apoptotic Asian Americans Asian ancestry Autoantibodies Autoantigens Autoimmune Diseases Autoimmunity BODIPY Bar Codes C57BL/6 Mouse Cell Separation Cells Classification Complex Development Disease Electron Microscopy End stage renal failure Engineering Environmental Exposure Epithelial Cells Etiology European Exhibits Exposure to Future Gene Frequency Genes Genetic Genetic Predisposition to Disease Genomics Genotype Glomerular Filtration Rate Glomerulonephritis Heritability Homeostasis Human IgG autoantibodies Immune Impairment Individual Inflammation Injury Injury to Kidney Interferon Type I Ions Iron Kidney Kidney Diseases Knock-in Knock-in Mouse LCN2 gene Lesion Leucocytic infiltrate Leukocytes Lipid Peroxidation Lupus Lupus Nephritis Macrophage Mediating Metabolic Mitochondria Modeling Molecular Mus NADPH Oxidase Nephritis Nuclear Oxidative Stress PTPRC gene Paraffin Embedding Pathogenesis Pathologic Pathway interactions Patients Phagocytes Predisposition Pristane Process Production Prognosis Proliferative Glomerulonephritis Proteinuria Protocols documentation Proximal Kidney Tubules Reactive Oxygen Species Role Sampling Serum Slide Stains Susceptibility Gene Suspensions Swelling Systemic Lupus Erythematosus TNFRSF5 gene Translations Tubular formation Variant Western Blotting causal variant cell type differential expression disease mechanisms study epidemiology study experimental study genetic variant glomerular filtration insight kidney biopsy kidney cell lupus like nephritis lupus-like mitochondrial dysfunction mortality mouse model nephrotoxicity neutrophil new therapeutic target novel nutrient absorption renal damage response risk variant sex single-cell RNA sequencing therapeutic development therapeutic target transcriptomics

项目摘要

Abstract: Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease with diverse manifestations characterized by the presence of autoantibodies to nuclear autoantigens and upregulated expression of type I interferon (IFN-I) stimulated genes. Epidemiology studies show that the strongest driver for the development of SLE is heritability, and SLE manifests when an environmental exposure of a genetically predisposed individual exceeds a liability threshold. We identified a p.Arg90His (p.R90H, rs201802880) substitution in neutrophil cytosolic factor (NCF1), encoding a hypofunctional, essential subunit of the phagocyte NADPH oxidase complex 2 (NOX2), as the strongest common risk variant associated with SLE in multiple ancestries, and showed association of the risk variant NCF1-H90 with kidney damage (defined by the presence of proteinuria >3.5g/24h, estimated glomerular filtration rate <50%, or end stage kidney disease [ESKD]) in SLE patients of Asian and African American ancestries. Lupus nephritis (LN) is a common severe manifestation of SLE that is initiated by glomerular accumulation of immune complexes that could incite inflammation in the glomeruli and tubulointerstitium (TI). TI inflammation -and not glomerulonephritis (GN)- on kidney biopsy predicts progression to ESKD in LN, one of the most important predictors of mortality in SLE. The primary target of the SLE-associated TI lesions relates to pathological remodeling in proximal tubule epithelial cells (PTEC); however, the underlying mechanisms and treatment targets remain unclear. To study the functional effects of the NCF1-H90 variant, we established a knock-in (KI) H90 variant in a non-autoimmune C57BL/6 (B6) background. Young naïve KI mice developed spontaneous autoimmunity, and pristane treatment induced proliferative GN and proteinuria, exhibiting increased follicular humoral responses and IgG autoantibody production, demonstrating the causality of this risk variant. The NCF1-H90 variant impaired apoptotic cell (AC) clearance by macrophages in B6 mice and SLE patients and expanded Tfh2 cells in a CD40 dependent manner, suggesting dysregulated mechanisms identified in Ncf1-H90 KI mice could be confirmed in NCF1-H90 expressing SLE patients. We observed exacerbated TI lesions induced by nephrotoxic serum (NTS) in Ncf1-H90 KI mice by systemic exposure to AC in B6 mice expressing another SLE risk variant. We hypothesize that imbalanced oxidative stress mediated by Ncf1-H90 could induce ferroptosis contributing to TI nephropathy. We will assess genotypic and sex effects in NTS or AC-induced nephritis to establish an LN-like TI nephropathy model to investigate if the Ncf1-H90 genotype affects iron homeostasis, lipid peroxidation and ferroptosis contributing to TI injury by altering transcriptomic profiles of renal infiltrated leukocytes and kidney resident cell subsets using single cell (sc) RNA-seq of CD45+ cells and kidney cells isolated from either NTS- or AC-treated WT and KI kidneys. Our findings will provide new insights into underlying mechanisms to identify potential therapeutic targets that could benefit LN patients carrying this common causal variant.

【摘要】：系统性红斑狼疮(SLE)是一种异质性自身免疫性疾病,具有多种发病机制。以存在核自身抗原的自身抗体且上调为特征的表现流行病学研究表明，I 型干扰素 (IFN-I) 刺激基因的表达最强。 SLE 的发展具有遗传性，当遗传因素暴露在环境中时，SLE 就会表现出来。我们确定了 p.Arg90His（p.R90H，rs201802880）。中性粒细胞胞浆因子 (NCF1) 的替代，编码吞噬细胞功能低下的必需亚基 NADPH 氧化酶复合物 2 (NOX2)，作为多种疾病中与 SLE 相关的最强常见风险变异体祖先，并显示风险变异 NCF1-H90 与肾损伤的关联（定义为存在 SLE 患者蛋白尿 >3.5g/24h、估计肾小球滤过率 <50% 或终末期肾病 [ESKD]）亚裔和非裔美国人的狼疮性肾炎 (LN) 是一种常见的严重表现。系统性红斑狼疮 (SLE) 由肾小球内免疫复合物的积累引发，可能会引发肾小球炎症肾活检可预测肾小球和肾小管间质 (TI) 炎症，而非肾小球肾炎 (GN)。 LN 进展中的 ESKD 是 SLE 死亡率最重要的预测因素之一。然而，SLE 相关的 TI 病变与近端小管上皮细胞 (PTEC) 的病理重塑有关；潜在的机制和治疗目标仍不清楚。为了研究 NCF1-H90 变体的功能效应，我们在非自身免疫 C57BL/6 (B6) 背景年轻的幼年 KI 小鼠出现自发性自身免疫，并且降植烷治疗诱导增殖性肾小球肾炎和蛋白尿，表现出滤泡体液反应增加和 IgG 自身抗体的产生，证明了这种风险变异 NCF1-H90 变异的因果关系。 B6 小鼠和 SLE 患者中巨噬细胞的凋亡细胞 (AC) 清除受损以及 Tfh2 细胞扩增以 CD40 依赖性方式，表明在 Ncf1-H90 KI 小鼠中发现的失调机制可能是我们在表达 NCF1-H90 的 SLE 患者中观察到肾毒性引起的 TI 病变加重。通过全身暴露于表达另一种 SLE 风险变异的 B6 小鼠的 AC 来检测 Ncf1-H90 KI 小鼠的血清（NTS）。我们认为 Ncf1-H90 介导的不平衡氧化应激可能会诱导铁死亡，从而导致我们将评估 NTS 或 AC 诱发的肾炎的基因型和性别影响，以建立 LN 样肾病。 TI 肾病模型研究 Ncf1-H90 基因型是否影响铁稳态、脂质过氧化和铁死亡通过改变肾脏浸润白细胞和肾脏的转录组谱来导致 TI 损伤使用从 NTS- 或 NTS 分离的 CD45+ 细胞和肾细胞的单细胞 (sc) RNA-seq 进行常驻细胞亚群经过 AC 处理的 WT 和 KI 肾脏，我们的研究结果将为识别潜在机制提供新的见解。可能使携带这种常见致病变异的 LN 患者受益的潜在治疗靶点。