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: 10555235
• 负责人: Nirmala Parajuli
• 金额: $ 47.73万
• 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/10555235
• 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; Mitogen-Activated Protein Kinase Inhibitor; Modeling; Molecular; Organ; Outcome; Pathogenesis; Pathologic; Pathway interactions; Patients; Perfusion; Persons; 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; cell type; clinically relevant; human disease; human model; immunoregulation; improved; improved outcome; in vivo; inflammatory modulation; inhibitor; insight; kidney cell; member; misfolded protein; mortality; multicatalytic endopeptidase complex; natural hypothermia; novel; novel therapeutic intervention; p38 Mitogen Activated Protein Kinase; pharmacologic; 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.

项目摘要摘要 对于从已故捐赠者那里接收肾脏的人来说，长期同种异体功能往往很差 占总移植物的70％。这些不良结果的关键因素是器官的冷藏（CS）， 在保存过程中诱导伤害。因此，迫切需要了解机制 CS激活了诱导受体肾损伤的分子途径。我们的长期目标是 识别这些与CS相关的途径并在CS期间应用有针对性的疗法以改善结果并减少 移植相关的死亡率。 CS诱导的肾脏损伤的重要分子决定因素之一是 异常蛋白质稳态。在压力期间，热激蛋白和蛋白酶体在 维持蛋白质稳态。 HSP72是HSC70的主要应力诱导同源物， 在所有成核细胞中都表现出管家功能的热冲蛋白70家族是必要的 用于细胞存活。重要的是，HSC70和HSP72通过结合受损的蛋白质并招募该关键作用 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就其保护作用而言，与许多人类疾病的发病机理有关 免疫系统和炎症。使用肾脏CS的临床相关大鼠模型与 移植，我们表明CS降低了蛋白酶体的功能，并损害了蛋白质的稳态 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的介导的激活介导HSP72的上调和RPT6的磷酸化， 导致蛋白酶体功能障碍和移植后损伤。我们有支持此的初步数据 假设。我们还建立了CS/移植的动物模型，这些动物模型更多地模仿了临床​​现实 有效地比简单的CS/温暖的灌注，将使我们能够通过3个特定目标检验假设。目的 1：定义HSP72上调的机理及其对肾脏CS期间蛋白酶体功能障碍的影响 移植。目标2：描述RPT6磷酸化/聚集的机制及其对 肾脏CS和移植过程中的蛋白酶体功能障碍。目标3：确定的治疗效用 HSP72抑制剂HS-72使用肾脏CS和移植的大鼠和人类模型。这个项目使用 临床上相关的大鼠肾移植模型以及体内人类肾脏灌注泵，以测试效果 基于CS的新型疗法（例如HS-72）在移植后蛋白酶体/肾功能。我们希望 确定CS和移植后蛋白酶体功能障碍和肾损伤的分子介质。这些 发现很容易翻译，例如通过给针对CS的这些途径的药物 改善移植结局并降低终末期肾脏患者的死亡率的解决方案 疾病。