Heme-mediated Mitochondrial Injury, Senescence, Acute Kidney Injury and Chronic Kidney Disease

血红素介导的线粒体损伤、衰老、急性肾损伤和慢性肾病

基本信息

批准号：
10656648
负责人：
KARL A. NATH
金额：
$ 59.92万
依托单位：
MAYO CLINIC ROCHESTER
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：
2023-03-15 至 2027-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10656648
关键词：
Acute Acute Renal Failure with Renal Papillary Necrosis Apoptosis Apoptotic Applications Grants Area Artificial Kidney Attention Automobile Driving CDKN2A gene Cell Cycle Cell Cycle Arrest Cell Proliferation Cell Survival Cells Cellular Stress Chronic Kidney Failure Clinical Trials Cytoprotection DNA Damage Dasatinib Data Dialysis procedure Disease Distant ETS1 gene End stage renal failure Endocrine Epithelial Cells Excision Exhibits Exposure to Family Genetic Geroscience Glycerol Heme Hemeproteins Hour Impairment In Vitro Induction of Apoptosis Inflammatory Injury Kidney Kidney Diseases Knockout Mice LOX gene Lamin B1 Link Mediating Metabolic Mitochondria Modeling Mus Organelles Pathogenesis Pathway interactions Phenotype Phosphoenolpyruvate Carboxylase Proteins Proximal Kidney Tubules Publishing Quercetin Reactive Oxygen Species Reducing Agents Renal function Reperfusion Injury Resistance Respiration Risk Factors Role Stains Testing Tetrapyrroles Therapeutic Tissues Tubular formation Up-Regulation age related aged cell age clinically relevant cytokine efficacy evaluation exposed human population fisetin genetic approach human old age (65+)in vitro Model in vivo in vivo Model indexing inhibitor injured insight lipophilicity mitochondrial dysfunction novel novel therapeutic intervention novel therapeutics paracrine pharmacologic recruit renal ischemia response senescence telomere tissue stress transcription factor

项目摘要

PROJECT SUMMARY Senescent cells (SCs) cause senescence, a dominant risk factor for acute kidney injury (AKI). SCs are cell cycle-arrested (due to upregulated cell cycle inhibitors p16Ink4a and p21Cip1) and display a senescence- associated secretory phenotype (SASP) which is proinflammatory and proapoptotic. Senolytics, agents that kill SCs, are now in clinical trials. We demonstrate senescence in the heme protein-mediated AKI model (HP-AKI) as indicated by multiple indices. The significance of such changes – injurious or protective – is unknown as regards AKI. The AKI field recognizes that mitochondrial injury drives AKI, while the senescence field recognizes that mitochondrial injury elicits senescence; this application uniquely unites these two concepts. Early in HP-AKI, we demonstrate that mitochondria are injured and their heme content increased; normal mitochondria, exposed to such heme content, cease functioning. Heme, a prooxidant tetrapyrrole, present in the ubiquitous family of heme proteins, is freed when heme proteins are destabilized because of cellular stress. We also demonstrate that heme induces p16Ink4a/p21Cip1 and a SASP, and suppresses PGC-1α. In exploring heme-induced mitochondrial injury and induction of p16Ink4a/p21Cip1, we focused on two transcription factors both upregulated by mitochondrial injury, one, ETS1, being an inducer of p16Ink4a, the other, ATF4, an inducer of p21Cip1. Our preliminary data demonstrate that these 4 principal molecules (ETS1, ATF4, p16Ink4a, p21Cip1) are all induced in HP-AKI; in heme-exposed renal proximal tubular epithelial cells in vitro; and in renal ischemia-reperfusion injury (IRI). Our hypothesis is that AKI results from heme-mediated mitochondrial injury and ensuing senescence, a thesis to be tested in three aims. Aim I: Define the role of heme-mediated mitochondrial injury in ETS1 and ATF4 expression, senescence, and AKI. Using complementary in vivo and in vitro approaches, we will sequentially examine the role of heme-mediated mitochondrial injury; the contribution of ETS1, ATF4, and ETS1/ATF4-independent pathways; and the involvement of senescence in AKI. Aim II: Define the roles of p21Cip1 and p16Ink4a in AKI: Genetic strategies. The role of p21Cip1 in AKI will be examined by inducible deletion of high p21Cip1-expressing cells and with proximal tubule-specific p21 KO mice. The role of p16Ink4a will be examined by inducible deletion of high p16Ink4a-expressing cells and by inducible proximal tubule-specific deletion of high p16Ink4a-expressing cells. Aim III: Define the effect of senolytics in AKI. SCs survive because of upregulated anti-apoptotic pathways, while senolytics kill SCs but not non-SCs. This aim examines the efficacy of senolytics in AKI, and in reducing the sensitivity of aged mice to AKI. In sum, this resubmitted R01 examines senescence in AKI, linking it sequentially to heme-mediated mitochondrial injury, the transcription factors ETS1 and ATF4, and p16Ink4a and p21Cip1. This R01 offers novel insights regarding the role of senescence in the pathogenesis of AKI and the therapeutic utility of senolytics.

项目概要衰老细胞 (SC) 导致细胞衰老，这是急性肾损伤 (AKI) 的主要危险因素。周期停滞（由于细胞周期抑制剂 p16Ink4a 和 p21Cip1 上调）并表现出衰老- 相关分泌表型 (SASP) 是促炎剂和促凋亡剂，是一种杀伤剂。 SC 目前正在进行临床试验，我们在血红素蛋白介导的 AKI 模型 (HP-AKI) 中证明了衰老。正如多个指数所表明的那样，这种变化的重要性——有害的或保护性的——尚不清楚。关于 AKI，AKI 领域认为线粒体损伤会导致 AKI，而衰老领域则认为是 AKI 的驱动因素。认识到线粒体损伤会引起衰老；该应用独特地将这两个概念结合起来。在 HP-AKI 早期，我们证明线粒体受到损伤，其血红素含量正常增加；暴露于此类血红素含量的线粒体会停止发挥血红素（一种促氧化剂四吡咯）的功能。当血红素蛋白因细胞应激而不稳定时，普遍存在的血红素蛋白家族就会被释放。我们还证明血红素诱导 p16Ink4a/p21Cip1 和 SASP，并抑制 PGC-1α。血红素诱导的线粒体损伤和 p16Ink4a/p21Cip1 的诱导，我们重点关注两个转录因子两者均因线粒体损伤而上调，一个是 ETS1，是 p16Ink4a 的诱导剂，另一个是 ATF4，是一种诱导剂我们的初步数据表明这 4 个主要分子（ETS1、ATF4、p16Ink4a、p21Cip1）均在体外和肾中暴露于血红素的肾近端肾小管上皮细胞中诱导；我们的假设是 AKI 是由血红素介导的线粒体损伤引起的。以及随之而来的衰老，该论文将在三个目标中进行测试：定义血红素介导的作用。 ETS1 和 ATF4 表达、衰老和 AKI 中的线粒体损伤。在体外方法中，我们将依次研究血红素介导的线粒体损伤的作用； ETS1、ATF4 和 ETS1/ATF4 独立途径的贡献以及衰老的参与； AKI。目标 II：定义 p21Cip1 和 p16Ink4a 在 AKI 中的作用：p21Cip1 在 AKI 中的作用。通过高 p21Cip1 表达细胞的诱导缺失和近端小管特异性 p21 KO 进行检查 p16Ink4a 的作用将通过诱导删除高表达 p16Ink4a 的细胞来检查。高 p16Ink4a 表达细胞的诱导性近端小管特异性缺失目标 III：定义 p16Ink4a 高表达细胞的作用。 AKI 中的 senolytics 因抗凋亡途径上调而得以存活，而 senolytics 则杀死 SC 该目的检查 senolytics 在 AKI 中的功效以及降低老年小鼠敏感性的功效。总之，这个重新提交的 R01 检查了 AKI 中的衰老，并将其与血红素介导的顺序联系起来。 R01 提供了新颖的线粒体损伤、转录因子 ETS1 和 ATF4 以及 p16Ink4a 和 p21Cip1。关于衰老在 AKI 发病机制中的作用以及 senolytics 的治疗效用的见解。