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

• 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
• 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

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.

项目摘要 衰老细胞（SC）导致衰老，这是急性肾损伤（阿基）的主要风险因素。SC是细胞 细胞周期停滞（由于细胞周期抑制剂p16 Ink 4a和p21 Cip 1上调）并显示衰老- 相关分泌表型（SASP），其是促炎和促凋亡的。Senolytics，代理人杀死 SC目前正在进行临床试验。我们在血红素蛋白介导的阿基模型（HP-AKI）中证明了衰老 如多个指数所示。这种变化的意义-伤害性或保护性-是未知的， 关于阿基阿基领域认识到线粒体损伤驱动阿基，而衰老领域认识到线粒体损伤驱动AKI。 认识到线粒体损伤加速衰老;本申请将这两个概念独特地结合起来。 在HP-AKI早期，我们证明线粒体受损，血红素含量增加;正常 暴露于这种血红素含量的线粒体停止功能。血红素，一种助氧化剂四吡咯，存在于 当血红素蛋白由于细胞应激而不稳定时，血红素蛋白的普遍存在的家族被释放。 我们还证明，血红素诱导p16 Ink 4a/p21 Cip 1和SASP，并抑制PGC-1α。探索 血红素诱导的线粒体损伤和p16 Ink 4a/p21 Cip 1的诱导，我们集中在两个转录因子 两者都被线粒体损伤上调，一个是p16 Ink 4a的诱导剂ETS 1，另一个是p16 Ink 4a的诱导剂ATF 4， p21cip1我们的初步数据表明，这4个主要分子（ETS 1，ATF 4，p16 Ink 4a，p21 Cip 1） 均在HP-AKI中诱导;在血红素暴露的体外肾近端肾小管上皮细胞中诱导;以及在肾细胞中诱导。 缺血再灌注损伤（IRI）。我们的假设是阿基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，这一论点将在三个目标中得到检验。目的一：明确血红素介导的 ETS 1和ATF 4表达、衰老和阿基中的线粒体损伤。使用体内互补 和体外方法，我们将依次检查血红素介导的线粒体损伤的作用; ETS 1、ATF 4和ETS 1/ATF 4非依赖性通路的贡献;以及衰老在 阿基目的二：明确p21 Cip 1和p16 Ink 4a在阿基中的作用：遗传策略。p21 Cip 1在阿基中的作用将 通过高表达p21 Cip 1的细胞的诱导性缺失和近端小管特异性p21 KO进行检查 小鼠p16 Ink 4a的作用将通过高表达p16 Ink 4a的细胞的可诱导缺失和通过细胞内的细胞毒性来检测。 高p16 Ink 4a表达细胞的可诱导近端小管特异性缺失。目标三：确定 阿基中的senolytics。由于上调的抗凋亡途径，SC存活，而senolytics杀死SC， 而不是非SC。本研究旨在检测抗衰老药物在阿基中的疗效，并降低老年小鼠的敏感性。 关于阿基总之，这个重新提交的R 01研究了阿基中的衰老，将其顺序地与血红素介导的 线粒体损伤、转录因子ETS 1和ATF 4以及p16 Ink 4a和p21 Cip 1。这款R 01提供了新颖的 关于衰老在阿基发病机制中的作用和衰老清除剂的治疗效用的见解。