Mechanisms of selective glycolytic inhibition in ischemic kidney proximal tubles

缺血肾近曲小管选择性糖酵解抑制机制

• 批准号: 8534448
• 负责人: BABU Joseph PADANILAM
• 金额: $ 15万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-14 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8534448
• 关键词: ATP Synthesis Pathway; Accounting; Acute Kidney Tubular Necrosis; Acute Renal Failure with Renal Papillary Necrosis; Address; Apoptosis Regulator; Apoptotic; Autophagocytosis; Biochemical; Biological Assay; Cell Death; Cell Death Inhibition; Cell Survival; Cells; Clinical; Data; Disease; Down-Regulation; Energy Metabolism; Enzymes; Event; Experimental Models; Fructose; Functional disorder; Genetic; Glucose; Glucose-6-Phosphate; Glyceraldehyde 3-Phosphate; Glyceraldehyde-3-Phosphate Dehydrogenases; Glycolysis; Health Care Costs; Human; Hypoxia; Injury; Intervention; Kidney; Link; Mediating; Metabolic; Methods; Molecular; Morbidity - disease rate; NADP; Necrosis; Nephrons; Organ; PARP inhibition; Pathogenesis; Pathway interactions; Pentosephosphate Pathway; Perfusion; Poly(ADP-ribose) Polymerases; Production; Pyruvate; Regulation; Renal Tissue; Reperfusion Injury; Reporting; Resort; Respiration; Role; Stress; Syndrome; Testing; abstracting; anaerobic glycolysis; base; fructose-6-phosphate; glycerate 1,3-biphosphate; in vivo; in vivo Model; innovation; mortality; novel; novel therapeutics; renal ischemia; response; success

Abstract Following ischemic renal injury (IRI), selective proximal straight tubule (PST) injury occurs in in vivo experimental models. Previous reports indicated that selective glycolytic inhibition and the consequent ATP depletion is the initiating cause that triggers all the subsequent events leading to PST injury and cell death to instigate renal dysfunction; however, the exact mechanism by which glycolysis is inhibited is not elucidated. Our recent report demonstrates that poly (ADP-ribose) Polymerase-1 (PARP-1) mediated inhibition of the key glycolytic enzyme, glyceraldehyde-3- phosphate dehydrogenase (GAPDH), can induce downregulation of glycolysis and ATP depletion in IRI. However, GAPDH inhibition by PARP-1 only partially accounted for ATP depletion, suggesting that synergetic inhibition at additional glycolytic steps may occur. The current proposal is based on new preliminary data indicating a novel paradigm that links p53 target TIGAR (Tp53 inducible glycolysis and apoptosis regulator) to metabolic regulation of the rate limiting glycolytic enzyme Phosphofructokinase (PFK) to induce ATP depletion and PST injury post-IRI. The objective of the proposal is to define the role and the mechanisms by which TIGAR regulate glycolytic energy metabolism in ischemic renal PST and determine whether synergistic inhibition of TIGAR and PARP- 1 protects from glycolytic inhibition and ATP depletion in the setting of IRI. The central hypothesis is that modulation of the activity of the key glycolytic enzymes, PFK and GAPDH by TIGAR and PARP-1 respectively, leads to downregulation of glycolysis and anaerobic ATP production in ischemic PSTs. Based on our strong preliminary data, the validity of the hypothesis will be tested by pursuing the following three specific aims: 1) determine the mechanism by which TIGAR activation in renal PSTs inhibits anaerobic energy production post-IRI; 2) determine if the level of ischemic stress switch TIGAR response towards ROS scavenging and autophagy versus glycolytic inhibition and cell death pathways post-IRI and 3) determine if synergetic inhibition of TIGAR and PARP activation completely protects PST from ischemic/hypoxic injury in in vivo models. Successful completion of the proposed studies, will establish a new paradigm on the role of PARP-1 and TIGAR as the primary mechanism that initiates glycolytic inhibition, ATP depletion and PST injury in IRI. The studies are innovative as a role for PARP-1 and TIGAR in glycolytic inhibition in a pathological condition such as ischemia/reperfusion injury has not been previously addressed in any organ. Results from the study may provide novel therapeutic opportunities to intervene in PARP-1 and TIGAR functions to modulate PST injury at its onset and may be extrapolated to intervene in the pathogenesis of human AKI.

摘要 缺血性肾损伤(IRI)后，体内发生选择性近端直管(PST)损伤 实验模型。先前的报道表明，选择性糖酵解抑制和 随之而来的ATP耗尽是触发所有后续事件的启动原因，导致 PST损伤和细胞死亡导致肾功能障碍；然而，其确切机制是 糖酵解被抑制的原因尚未阐明。我们最近的报告表明，聚(ADP-核糖) 聚合酶-1(PARP-1)介导的关键糖酵解酶-3-甘油醛的抑制 磷酸脱氢酶(GAPDH)可诱导心肌细胞糖酵解下调和ATP耗竭 IRI。然而，PARP-1对GAPDH的抑制只是ATP耗竭的部分原因，提示 在额外的糖酵解步骤中可能会发生协同抑制。目前的提案是基于 新的初步数据表明，将p53靶标TIGAR(TP53可诱导)连接到一个新的范例 糖酵解和细胞凋亡调节剂)对限速糖酵解酶的代谢调节 磷酸果糖激酶(PFK)诱导缺血再灌注后ATP耗竭和PST损伤。该计划的目标是 建议定义TIGAR调节糖酵解能量的作用和机制 检测TIGAR和PARP协同抑制对缺血肾PST代谢的影响 1在IRI环境下保护糖酵解抑制和ATP耗竭。中心假说 是TIGAR和TIGAR对关键糖酵解酶PFK和GAPDH活性的调节 PARP-1分别导致缺血期糖酵解和无氧三磷酸腺苷生成下调 PSTS。基于我们强大的初步数据，我们将通过追查来检验假设的有效性 以下三个具体目标：1)确定TIGAR在肾脏中激活的机制 PSTS抑制IRI后的无氧能量产生；2)确定缺血应激水平是否切换 TIGAR对ROS清除和自噬的反应与糖酵解抑制和细胞死亡的比较 IRI后通路和3)是否完全协同抑制TIGAR和PARP的激活 在活体模型中保护PST免受缺血/缺氧损伤。圆满完成拟议中的 研究将建立一个关于PARP-1和TIGAR作为主要机制的作用的新范式 引发糖酵解抑制、ATP耗竭和PST损伤。这些研究具有创新性，因为 PARP-1和TIGAR在糖酵解抑制中的作用 缺血/再灌注损伤以前没有在任何器官中得到解决。研究结果 可能为干预PARP-1和TIGAR功能调节提供新的治疗机会 PST在发病时的损伤，并可能外推干预人类AKI的发病机制。