Targeting heat shock protein 72 to improve renal function after transplantation

靶向热休克蛋白72改善移植后肾功能

• 批准号: 10371148
• 负责人: Nirmala Parajuli
• 金额: $ 51.49万
• 依托单位: UNIV OF ARKANSAS FOR MED SCIS
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-15 至 2026-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10371148
• 关键词: Affect; Allografting; Animal Model; Binding; Bioinformatics; Cadaver; Cell Survival; Cells; Clinical; Cryopreservation; Data; Disease; Drug Targeting; End stage renal failure; Exhibits; Family; Functional disorder; Generations; Genetic; Goals; HSF1; HSP72 protein; Harvest; Heat shock proteins; Heat-Shock Proteins 70; Homologous Gene; Housekeeping; Hsc70 protein; Human; Immune system; Impairment; In Vitro; Inflammation; Inflammatory Response; Infusion Pumps; Injury; Injury to Kidney; Kidney; Kidney Transplantation; Link; Mass Spectrum Analysis; Mediating; Mediator of activation protein; Modeling; Molecular; Organ; Outcome; Pathogenesis; Pathologic; Pathway interactions; Patients; Perfusion; Persons; Pharmacology; Phosphorylation; Play; Process; Proteins; Rattus; Renal Tissue; Renal function; Reperfusion Therapy; Role; Site; Small Interfering RNA; Stress; Testing; Therapeutic; Tissues; Translating; Transplant Recipients; Transplantation; Up-Regulation; Work; base; cell type; clinically relevant; human disease; human model; improved; improved outcome; in vivo; inhibitor; insight; kidney cell; member; misfolded protein; mortality; multicatalytic endopeptidase complex; novel; novel therapeutic intervention; preservation; prevent; protein degradation; proteostasis; recruit; renal damage; targeted treatment; therapeutic target; tissue injury; transcription factor; transplant model

PROJECT SUMMARY ABSTRACT Long-term allograft function tends to be poor for people who receive kidneys from deceased donors, which comprise 70% of total transplants. A key contributor to these poor outcomes is cold storage (CS) of the organs, which induces injury during preservation. Accordingly, there is an urgent need to understand the mechanisms by which CS activates molecular pathways that induce renal damage in the recipient. Our long-term goal is to identify these CS-related pathways and apply targeted therapies during CS to improve outcomes and decrease transplant-associated mortality. One of the important molecular determinants of CS-induced kidney injury is abnormal protein homeostasis. During stress, heat-shock proteins and the proteasome play a concerted role in maintaining protein homeostasis. Hsp72 is the major stress-inducible homologue of Hsc70, the cognate member of the heat-shock protein 70 family that exhibits housekeeping function in all nucleated cells and is necessary for cell survival. Importantly, Hsc70 and Hsp72 play critical roles by binding damaged proteins and recruiting the proteasome for targeted degradation, preventing the nonspecific aggregation of damaged proteins. In addition to its protective roles, Hsp72 is implicated in the pathogenesis of numerous human diseases by modulating the immune system and inflammation. Using a clinically relevant rat model of renal CS combined with transplantation, we showed that CS decreases proteasome function and impairs protein homeostasis in the transplants. How CS decreases proteasome function in the transplants is not known. We hypothesize that CS- mediated activation of HSF1 and p38MAPK mediate the upregulation of Hsp72 and phosphorylation of Rpt6, leading to proteasome dysfunction and injury after transplantation. We have preliminary data supporting this hypothesis. We have also established animal models of CS/transplantation, which mimic the clinical reality more effectively than simple CS/warm perfusion and will allow us to test our hypothesis through 3 specific aims. Aim 1: Define the mechanism of Hsp72 upregulation and its impact on proteasome dysfunction during renal CS and transplantation. Aim 2: Delineate the mechanism of Rpt6 phosphorylation/aggregation and its impact on proteasome dysfunction during renal CS and transplantation. Aim 3: Determine the therapeutic utility of the Hsp72 inhibitor HS-72 using both rat and human models of renal CS and transplantation. This project uses a clinically relevant rat kidney transplant model as well as ex vivo human kidney perfusion pump to test the effects of novel CS-based therapies (e.g., HS-72) on proteasome/renal function after transplantation. We expect to identify molecular mediators of proteasome dysfunction and renal injury following CS and transplantation. These findings would be readily translatable, such as by administering drugs targeting these pathways to the CS solution to improve transplant outcomes and reduce mortality for transplant patients with end-stage kidney disease.

项目总结摘要 对于从已故捐赠者那里接受肾脏的人来说，长期的同种异体移植功能往往很差，这 占移植总量的70%。造成这些不良结果的一个关键因素是器官的冷藏(CS)， 在保存过程中会造成伤害。因此，迫切需要了解这些机制。 通过CS激活分子通路，导致受者肾脏损伤。我们的长期目标是 找出这些与CS相关的途径，并在CS期间应用有针对性的治疗以改善结果并减少 移植相关死亡率。CS致肾损伤的重要分子决定因素之一是 蛋白质动态平衡异常。在应激过程中，热休克蛋白和蛋白酶体在 维持蛋白质动态平衡。Hsp72是同源成员Hsc70的主要应激诱导同源物 热休克蛋白70家族中的一种，在所有有核细胞中表现出管家功能，是必需的 为了细胞的生存。重要的是，Hsc70和Hsp72通过结合受损蛋白和招募 用于靶向降解的蛋白酶体，防止受损蛋白质的非特异性聚集。此外 HSP72的保护性作用是通过调节HSP72基因的表达，参与多种人类疾病的发病机制。 免疫系统和炎症。应用临床相关的肾综合征出血热大鼠模型 移植后，我们发现CS降低了蛋白酶体功能，破坏了蛋白质稳态。 移植。CS如何降低移植中的蛋白酶体功能尚不清楚。我们假设CS- HSF1和p38MAPK介导HSP72上调和Rpt6磷酸化， 导致移植后蛋白酶体功能障碍和损伤。我们有初步数据支持这一点 假设。我们还建立了CS/移植的动物模型，更接近临床实际 比简单的CS/温灌注法更有效，并将允许我们通过3个特定的目标来检验我们的假设。目标 1：明确HSP72上调的机制及其对蛋白酶体功能障碍的影响 移植。目的2：阐明Rpt6磷酸化/聚集的机制及其对蛋白表达的影响 蛋白酶体功能障碍在肾脏CS和移植中的应用。目标3：确定药物的治疗效用 HSP72抑制剂HS-72在大鼠和人肾CS和移植模型中的应用。此项目使用 临床相关大鼠肾移植模型及体外人肾灌注泵的实验研究 基于CS的新疗法(如HS-72)对移植后蛋白酶体/肾功能的影响。我们希望 确定CS和移植后蛋白酶体功能障碍和肾脏损伤的分子介质。这些 这些发现很容易翻译，例如通过给CS提供针对这些通路的药物 改善终末期肾移植患者移植结局和降低死亡率的解决方案 疾病。