Targeting ferroptosis in renal tubular epithelial cells to improve outcomes of lupus nephritis

靶向肾小管上皮细胞铁死亡以改善狼疮性肾炎的预后

• 批准号: 10638468
• 负责人: Laurence Morel
• 金额: $ 49.31万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-01 至 2028-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10638468
• 关键词: Adverse effects; Animals; Antibodies; Antigen-Antibody Complex; Attenuated; Autoantibodies; Biological; Bone Marrow; CD4 Positive T Lymphocytes; Cell Death; Cell surface; Cells; Chimera organism; Coenzyme A Ligases; Complex; Congenic Mice; Cystine; Data; Dependence; Deposition; Disease; Dose; End stage renal failure; Enzymes; Epithelial Cells; Etiology; Exposure to; Family; Family member; Foundations; Generations; Genes; Genetic Transcription; Glomerulonephritis; Glutathione; Human; Immune Complex Glomerulonephritis; Immunoglobulin G; Immunoglobulins; Immunosuppression; Immunosuppressive Agents; Impairment; Inflammation; Inflammatory; Injury; Injury to Kidney; Iron; Kidney; Kidney Failure; Lead; Lipid Peroxidation; LoxP-flanked allele; Lupus; Lupus Nephritis; Mediating; Medical; Modeling; Molecular; Mus; Nephritis; Organ; Outcome; Pathology; Pathway interactions; Patients; Polyunsaturated Fatty Acids; Predisposition; Proteinuria; Recycling; Renal glomerular disease; Renal tubule structure; Resistance; Sampling; Serum; Sorting; System; Systemic Lupus Erythematosus; Testing; Therapeutic; Treatment Efficacy; Tubular formation; cell injury; cohort; design; improved outcome; in vivo; inhibitor; kidney epithelial cell; lipidomics; lupus prone mice; mRNA Precursor; member; mouse model; nephrotoxicity; neutralizing antibody; new therapeutic target; novel; novel strategies; oxidation; promoter; protein biomarkers; solute; therapeutic target; uptake

PROJECT SUMMARY/ABSTRACT Lupus nephritis is one of the most severe end-organ manifestations of systemic lupus erythematosus. Immunosuppression, the cornerstone for treating this disease, is complicated by many adverse effects. Although traditionally considered as a glomerular disease, up to 80% of lupus nephritis patients present with tubular injury, and tubular injury is a better predictor of progression to end stage kidney disease than glomerular injury. This identifies the renal tubules as a therapeutic target in lupus nephritis. The complex biological mechanisms that underlie tubular epithelial cell injury in lupus nephritis remain, for the most part, obscure. We propose to provide such a mechanistic understanding by leveraging our key novel findings. We have shown that iron accumulates in the tubular compartment of the lupus nephritis kidneys but not in the glomeruli. Most of the iron recycling in the kidney is performed by proximal tubular epithelial cells, and excess iron induces ferroptosis -- an inflammatory form of cell death characterized by high levels of lipid peroxidation. Ferroptosis is mostly observed in the tubular segments of human and murine lupus nephritis kidneys. We have found that the enzyme Acyl-CoA synthetase long-chain family member 4 (ACSL4), a ferroptosis promoter, was increased whereas SLC7A11, a ferroptosis inhibitor, was decreased in lupus nephritis. Additionally, human lupus nephritis serum induced ferroptosis in proximal tubular epithelial cells and this was associated with inflammation and injury. Liproxstain-2, a novel ferroptosis inhibitor, blocked these outcomes. These data led us to hypothesize that iron accumulation in proximal tubular epithelial cells promotes ferroptosis, propagates tubulointerstitial inflammation and worsens outcomes of lupus nephritis. We aim to test this hypothesis using congenic mice deficient for ACSL4 (Acsl4PTEC-/-) and SCL7A11 (Slc7a11PTEC-/-) only in their proximal tubular epithelial cells (PTEC). We will first investigate the resistance of Acsl4PTEC-/- and susceptibility of Slc7a11PTEC-/- mice to ferroptosis using an inducible and a spontaneous mouse model of immune complex glomerulonephritis, identify the downstream molecular pathways that block or lead to ferroptosis and follow the outcomes of kidney injury. Using lupus nephritis patients and healthy controls, we will dissect the ferroptosis inducing ability of whole and immunoglobin depleted serum on proximal tubular epithelial cells as well as test novel ACSL4 inhibitors. Using purified cells from the same cohort of patients and controls we will block known repressors of SLC7A11 and evaluate outcomes of ferroptosis and tubular pathology. Finally, we will evaluate the in vivo therapeutic efficacy of Liproxstain-2 in two spontaneous murine models of lupus nephritis with existing renal injury. These studies will identify novel mechanisms of proximal tubular epithelial cell injury in lupus nephritis and support use of ferroptosis inhibitors as a novel adjunct therapy to reduce dependency on traditional immunosuppressants.

项目概要/摘要 狼疮性肾炎是系统性红斑狼疮最严重的终末器官表现之一。 免疫抑制是治疗这种疾病的基石，但由于许多不良反应而变得复杂。虽然 传统上被认为是一种肾小球疾病，高达 80% 的狼疮性肾炎患者出现肾小管损伤， 与肾小球损伤相比，肾小管损伤更能预测终末期肾病的进展。这 将肾小管确定为狼疮性肾炎的治疗靶点。复杂的生物学机制 狼疮性肾炎中肾小管上皮细胞损伤的机制在很大程度上仍不清楚。我们建议提供 通过利用我们的关键新颖发现来实现这种机械性的理解。 我们已经证明，铁积聚在狼疮性肾炎肾脏的管状室中，但没有积聚。 在肾小球中。肾脏中的大部分铁回收是由近端肾小管上皮细胞进行的，并且 过量的铁会引起铁死亡——一种以高脂质水平为特征的炎症性细胞死亡形式 过氧化。铁死亡主要见于人类和小鼠狼疮性肾炎的肾小管段 肾脏。我们发现酰基辅酶A合成酶长链家族成员4（ACSL4）是一种 在狼疮性肾炎中，铁死亡启动子增加，而铁死亡抑制剂 SLC7A11 减少。 此外，人狼疮肾炎血清诱导近端肾小管上皮细胞铁死亡，这是 与炎症和损伤有关。 Liproxstain-2 是一种新型铁死亡抑制剂，可以阻止这些结果。 这些数据使我们推测近端肾小管上皮细胞中铁的积累促进 铁死亡，传播肾小管间质炎症并恶化狼疮性肾炎的结果。我们的目标是测试 该假设仅使用缺乏 ACSL4 (Acsl4PTEC-/-) 和 SCL7A11 (Slc7a11PTEC-/-) 的同类小鼠 近端肾小管上皮细胞（PTEC）。我们将首先研究 Acsl4PTEC-/- 的耐药性和敏感性 使用免疫复合物的诱导型和自发性小鼠模型导致 Slc7a11PTEC-/- 小鼠铁死亡 肾小球肾炎，确定阻断或导致铁死亡的下游分子途径并遵循 肾损伤的结果。使用狼疮性肾炎患者和健康对照，我们将剖析铁死亡 全血清和免疫球蛋白耗尽血清对近端肾小管上皮细胞的诱导能力以及测试 新型 ACSL4 抑制剂。使用来自同一组患者和对照的纯化细胞，我们将阻断已知的 SLC7A11 的阻遏物并评估铁死亡和肾小管病理​​学的结果。最后，我们将评估 Liproxstain-2 在两种自发性狼疮肾炎小鼠模型中的体内治疗效果 肾损伤。这些研究将确定狼疮近端肾小管上皮细胞损伤的新机制 肾炎并支持使用铁死亡抑制剂作为一种新型辅助疗法，以减少对传统疗法的依赖 免疫抑制剂。