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）是一种异质自身免疫性疾病以核自动抗体的自身抗体为特征的表现形式并更新 I型干扰素（IFN-I）刺激基因的表达。流行病学研究表明，强大的驱动力 SLE的发展是遗传力的，当环境暴露于一般的环境时，SLE会表现出来倾向的人超过责任阈值。我们确定了P.Arg90His（P.R90H，RS201802880）取代中性粒细胞胞质因子（NCF1），编码吞噬细胞的低功能性亚基 NADPH氧化物复合物2（NOX2），作为与多个SLE相关的强常见风险变体祖先，并显示了风险变体NCF1-H90与肾脏损害的关联（由存在定义蛋白尿> 3.5G/24H，估计的肾小球过滤率<50％或SLE终末期肾脏疾病[ESKD]）亚裔和非裔美国人的患者。狼疮肾炎（LN）是常见的严重表现由免疫复合物的肾小球积累引发的SLE，可能会促进注射肾小球和肾小管Interstitium（Ti）。 Ti炎症 - 不是肾小球肾炎（GN） - 肾脏活检预测在LN中向ESKD发展，LN是SLE死亡率最重要的预测指标之一。主要目标与近端细胞上皮细胞中病理重塑有关的SLE相关TI病变（PTEC）；然而，潜在的机制和治疗目标尚不清楚。为了研究NCF1-H90变体的功能效应，我们在A中建立了一个敲门（Ki）H90变体非自动免疫C57BL/6（B6）背景。年轻的幼体小鼠开发了赞助的自动免疫，然后丙烷处理诱导的GN和蛋白尿，表现出增加的卵泡体液反应和IgG自身抗体产生，证明了这种风险变异的因果关系。 NCF1-H90变体 B6小鼠和SLE患者中巨噬细胞的凋亡细胞（AC）清除受损，并扩大了TFH2细胞以CD40的方式，表明在NCF1-H90 Ki小鼠中鉴定出的失调机制可能是在表达SLE患者的NCF1-H90中确认。我们观察到肾毒性诱导的Ti水平加剧 NCF1-H90 Ki小鼠中的血清（NTS）通过全身暴露于AC中的AC中，表达了另一种SLE风险变体。我们假设由NCF1-H90介导的氧化胁迫不平衡可能诱导促进性铁血作用 Ti肾病。我们将评估NTS或AC诱导的肾炎中的基因型和性别作用，以建立LN样 Ti肾病模型研究NCF1-H90基因型是否影响铁稳态，脂质过氧化和通过改变肾脏浸润的白细胞和肾脏的转录组轮廓，导致Ti损伤的铁质吞噬作用使用从NTS-或经AC处理的WT和Ki Kidsneys。我们的发现将为识别基本机制提供新的见解潜在的治疗靶标，可以使携带这种常见因果变异的LN患者受益。