Ferroptosis and Ferroptotic Stress in Maladaptive Renal Repair

适应不良肾修复中的铁死亡和铁死亡应激

• 批准号: 10655821
• 负责人: Tomokazu Souma
• 金额: $ 52.38万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-15 至 2028-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10655821
• 关键词: Acceleration; Acute; Acute Renal Failure with Renal Papillary Necrosis; Affect; Attenuated; COVID-19; Cardiovascular system; Cell Culture Techniques; Cell Death; Cell membrane; Cells; Cessation of life; Chronic; Chronic Kidney Failure; Clinical; Data; Dependence; Development; Dialysis procedure; Disease; Doxycycline; ESR1 gene; Environment; Estrogen Receptors; Estrogens; Event; Exhibits; Female; Fibrosis; GPER gene; Genetic; Gonadal Steroid Hormones; Health; Histopathology; Hormonal; Hospitalization; Human; Immune; Immune response; Impairment; In Vitro; Inflammation; Inflammatory; Injury to Kidney; Interruption; Investigation; Ischemia; Kidney; Knockout Mice; Knowledge; Lipid Peroxidation; Lipid Peroxides; Longitudinal Studies; LoxP-flanked allele; Modeling; Molecular; Mus; Mutant Strains Mice; Operative Surgical Procedures; Organ; Organoids; Outcome; Ovariectomy; Pathogenesis; Pathogenicity; Pathologic; Pathway interactions; Patients; Pharmacology Study; Phenotype; Predisposition; Process; Receptor Signaling; Recovery; Reduced Glutathione; Regulation; Regulatory Pathway; Renal function; Reperfusion Injury; Research; Residual state; Resolution; Risk; Rupture; Sex Differences; Stress; Tamoxifen; Testing; Testosterone; Therapeutic Effect; Transcription Alteration; Tubular formation; design; early experience; epithelial injury; female sex hormone; glutathione peroxidase; high risk; improved; in vivo Model; induced pluripotent stem cell; inhibitor; injury recovery; insight; ischemic injury; kidney fibrosis; kidney repair; male; mortality; mouse genetics; mouse model; new therapeutic target; novel; novel therapeutics; pharmacologic; pre-clinical; prevent; repaired; resilience; response; sex; sexual dimorphism; stress resilience; targeted treatment; transcriptomics

PROJECT SUMMARY Acute kidney injury (AKI) is a major health problem, afflicting 1.2 million hospitalized patients annually in the US. Maladaptive renal repair after AKI promotes development of chronic kidney disease (CKD), leaving affected patients at high risk for dialysis dependency, cardiovascular events, and mortality. Studies show that males are disproportionately and more severely affected by AKI than females, including COVID-19-associated AKI. However, the molecular mechanisms underlying this sexual dimorphism remain poorly understood. Moreover, there are no targeted therapies that interrupt this devastating disease process in both sexes. Using single-cell transcriptomics and mouse genetics, our ongoing studies found that the female sex confers marked protection against ferroptosis, a distinct, non-apoptotic form of regulated cell death and a critical driver of maladaptive repair after AKI in mice and humans. Ferroptosis is triggered by the inability of glutathione peroxidase 4 (GPX4) to remove toxic lipid peroxides from cell membranes, leading to the accelerated accumulation of toxic lipid peroxides (ferroptotic stress) and cell rupture. Acute ischemic and toxic kidney injuries reduce GPX4 in proximal tubular (PT) cells, thus making these cells vulnerable to ferroptosis. Severe AKI also induces pathologic transcriptional alteration of PT cells into an inflammatory phenotype and prevents their recovery to a healthy state (impaired plasticity). Our data show that in males but not in females, genetic deletion of Gpx4 promotes the accumulation of inflammatory PT cells and triggers their death by ferroptosis. To advance these clinically impactful lines of investigation, we will test our overarching hypothesis that sexual dimorphism in resilience to ferroptosis underlies sex differences in clinical outcomes after AKI. We further hypothesize that uncovering the mechanisms of how sex hormones regulate ferroptosis sensitivity will enable identification of targetable downstream pathways that improve AKI outcomes for both sexes. Directly testing these hypotheses, we will integrate unbiased single-cell transcriptomics, genetic mouse models, pharmacological studies, and human kidney organoids with two Specific Aims. In Aim 1, we will determine sex-dependent mechanisms by which ferroptosis promotes maladaptive repair at single-cell resolution using our tubule-specific, doxycycline-inducible Gpx4 knockout mouse model. We will also investigate the therapeutic effects of ferroptosis inhibitors to enhance renal repair in our murine kidney injury models in vivo and in human in vitro AKI models using organoids. In Aim 2, we will test our hypothesis that sex hormones regulate the sensitivity to ferroptosis and PT cell plasticity after AKI using gonadectomy and genetic inhibition of estrogen receptor signaling. The results of these studies will provide compelling preclinical mechanistic evidence for how ferroptotic stress governs PT cell fate. Our studies will identify new therapeutic targets to enhance renal ferroptotic stress resilience and promote healthy PT recovery from injury, thereby interrupting the AKI to CKD transition in both sexes.

项目摘要 急性肾损伤（阿基）是一个主要的健康问题，在美国每年折磨120万住院患者。 阿基后适应不良的肾脏修复促进慢性肾脏疾病（CKD）的发展， 透析依赖、心血管事件和死亡率高风险患者。研究表明， 与女性相比，阿基的影响不成比例且更严重，包括COVID-19相关的阿基。 然而，这种两性异形的分子机制仍然知之甚少。此外，委员会认为， 目前还没有针对性的治疗方法来中断这种对男女都有破坏性的疾病进程。使用单细胞 转录组学和小鼠遗传学，我们正在进行的研究发现，女性赋予显着的保护， 针对铁细胞凋亡，一种独特的、非凋亡形式的调节性细胞死亡，也是适应不良修复的关键驱动因素 在小鼠和人类的阿基之后。铁凋亡是由谷胱甘肽过氧化物酶4（GPX 4）不能 从细胞膜中清除有毒的脂质过氧化物，导致有毒脂质的加速积累 过氧化物（亚铁氧化应激）和细胞破裂。急性缺血性和中毒性肾损伤减少近端GPX 4 肾小管（PT）细胞，从而使这些细胞易受铁凋亡。严重阿基还诱导病理性 PT细胞转录改变成炎性表型，并阻止其恢复到健康状态。 可塑性受损（impaired plasticity）。我们的数据表明，在男性中，而不是在女性中，Gpx 4的基因缺失促进了 炎性PT细胞的积累并通过铁凋亡引发其死亡。为了在临床上推进这些 有影响力的调查路线，我们将测试我们的总体假设，即性二型性的弹性， 铁性下垂是阿基后临床结局性别差异的基础。我们进一步假设， 性激素如何调节铁凋亡敏感性的机制将能够识别靶向的 下游途径，改善阿基的结果为两种性别。直接测试这些假设，我们将 整合无偏单细胞转录组学、遗传小鼠模型、药理学研究和人类 具有两个特定目标的肾脏类器官。在目标1中，我们将确定性别依赖机制， 铁凋亡促进单细胞分辨率的适应不良修复，使用我们的小管特异性，多西环素诱导 Gpx 4基因敲除小鼠模型。我们还将研究铁凋亡抑制剂的治疗效果，以增强 在我们的鼠肾损伤模型体内和人体外阿基模型中使用类器官的肾修复。在Aim中 2，我们将测试我们的假设，即性激素调节铁凋亡和PT细胞可塑性的敏感性， 使用性腺切除术和雌激素受体信号传导的遗传抑制的阿基。这些研究的结果将 提供了令人信服的临床前机制的证据，铁中毒应激如何支配PT细胞的命运。我们的研究 将确定新的治疗靶点，以增强肾铁中毒应激恢复能力，促进健康的PT 从损伤中恢复，从而在两种性别中中断阿基向CKD的转变。