Tsg101 and endosomes in cardiac surgery-induced injury

Tsg101 和内体在心脏手术引起的损伤中的作用

• 批准号: 10066356
• 负责人: Guo-Chang Fan
• 金额: $ 30.5万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-12-10 至 2022-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10066356
• 关键词: Acceleration; Address; Adult; Anaerobic Bacteria; Animals; Antibiotics; Binding; Bone Marrow Stem Cell; Cardiac; Cardiac Myocytes; Cardiac Surgery procedures; Cell Survival; Cessation of life; Clinical Trials; Complex; Coronary Artery Bypass; Data; Endosomes; Energy-Generating Resources; Family; Fatty Acids; Generations; Genes; Glucose; Glucose Transporter; Glycogen; Glycolysis; Heart; Heart Injuries; Human; Hypoxia; Impairment; Infarction; Infusion procedures; Injections; Injury; Insulin; Insulin Resistance; Ischemia; Knowledge; Lentivirus Vector; Measures; Mediating; Membrane; Membrane Proteins; Mesenchymal Stem Cells; Mission; Mitochondria; Morbidity - disease rate; Mus; Muscle Cells; Myocardial; Myocardial Ischemia; Operative Surgical Procedures; Outcome; Oxygen Consumption; Pathway interactions; Patients; Play; Postoperative Period; Potassium; Production; Protein Isoforms; Proteins; Public Health; Recombinants; Recovery of Function; Recycling; Regulation; Reperfusion Injury; Reperfusion Therapy; Research; Role; Sarcolemma; Sorting - Cell Movement; Source; Stress; Surface; TSG101 gene; Testing; Therapeutic; Translating; Transplantation; United States National Institutes of Health; Up-Regulation; Work; anaerobic glycolysis; attenuation; base; cardioprotection; disability; exosome; glucose uptake; heart damage; improved; in vivo; knock-down; mortality; mouse model; nanovesicle; novel; overexpression; oxidation; pre-clinical; prevent; protective effect; receptor; recruit; small hairpin RNA; tool; translational study; Acceleration; Address; Adult; Anaerobic Bacteria; Animals; Antibiotics; Binding; Bone Marrow Stem Cell; Cardiac; Cardiac Myocytes; Cardiac Surgery procedures; Cell Survival; Cessation of life; Clinical Trials; Complex; Coronary Artery Bypass; Data; Endosomes; Energy-Generating Resources; Family; Fatty Acids; Generations; Genes; Glucose; Glucose Transporter; Glycogen; Glycolysis; Heart; Heart Injuries; Human; Hypoxia; Impairment; Infarction; Infusion procedures; Injections; Injury; Insulin; Insulin Resistance; Ischemia; Knowledge; Lentivirus Vector; Measures; Mediating; Membrane; Membrane Proteins; Mesenchymal Stem Cells; Mission; Mitochondria; Morbidity - disease rate; Mus; Muscle Cells; Myocardial; Myocardial Ischemia; Operative Surgical Procedures; Outcome; Oxygen Consumption; Pathway interactions; Patients; Play; Postoperative Period; Potassium; Production; Protein Isoforms; Proteins; Public Health; Recombinants; Recovery of Function; Recycling; Regulation; Reperfusion Injury; Reperfusion Therapy; Research; Role; Sarcolemma; Sorting - Cell Movement; Source; Stress; Surface; TSG101 gene; Testing; Therapeutic; Translating; Transplantation; United States National Institutes of Health; Up-Regulation; Work; anaerobic glycolysis; attenuation; base; cardioprotection; disability; exosome; glucose uptake; heart damage; improved; in vivo; knock-down; mortality; mouse model; nanovesicle; novel; overexpression; oxidation; pre-clinical; prevent; protective effect; receptor; recruit; small hairpin RNA; tool; translational study

Heart surgery for both coronary artery bypass graft (CABG) and transplantation often involves cardiac ischemia/reperfusion (I/R), which leads to a switch of the myocardial energy source from fatty acid β- oxidation to anaerobic glycolysis. As an adaptation, Glut-4, a major isoform of the glucose transporters in the heart, is recruited to the cardiomyocyte surface (also called sarcolemma) to take up glucose and stimulate cardiac ATP production. Nonetheless, such compensatory Glut4 translocation is not sufficient to meet cardiac glucose demands for ATP generation in I/R hearts and thereby, results in an energy crisis. Notably, recent multiple large clinical trials involving infusion of glucose-insulin-potassium (GIK) solution into patients undergoing cardiac surgery have not shown any positive results (or even worse). Therefore, exploring how to augment Glut-4 translocation and glucose utilization, independent of insulin, is desperately needed to counter I/R-triggered cardiac energy loss. We recently made the novel findings that the tumor susceptibility gene 101 (Tsg101), a central component of the ESCRT (endosomal sorting complexes required for transport) machinery, is able to regulate the endosomal recycling of membrane receptors in animal hearts. Our newest data further showed that: 1) Tsg101 binds directly to Glut-4 in adult mouse hearts; 2) forced expression of Tsg101 in cultured myocytes resulted in higher levels of sarcolemma Glut-4 and improved cell survival when challenged with hypoxia/reoxygenation; and 3) Tsg101 up-regulates the expression of Rab11a and FIP3 (Rab11-family interacting protein 3), two key factors involved in endosomal recycling. Most importantly, our pilot data also showed that a group of naturally-occurring nano-vesicles, exosomes, released by bone- marrow stem cells, can effectively deliver Tsg101 into cardiac myocytes. Based on these initial findings, we hypothesize that Tsg101 can reduce or prevent cardiac I/R-induced energy crisis/injury by promoting Rab11a/ FIP3-mediated endosomal recycling of Glut-4. Treatment of mouse hearts with Tsg101-containing exosomes before ischemia or during early reperfusion can elevate myocardial Tsg101, thereby limiting I/R-triggered cardiac damage. The work proposed here will address three specific aims: 1) Define the role of Tsg101 in glucose-dependent energy generation and cardio-protection from I/R injury, using both heart-specific Tsg101-overexpressing and inducible knockdown mouse models; 2) Identify whether Tsg101-induced cardio-protection is dependent on Rab11a/FIP3-mediated endosomal recycling of Glut-4; and 3) Investigate the therapeutic potential of Tsg101 to prevent/reduce I/R-induced cardiac energy stress and injury, using Tsg101-loaded exosomes. The proposed studies are expected to identify Tsg101 as a novel regulator of Glut-4 translocation and as a major cardio-protector against I/R-induced energy stress. If verified, the findings from this proposal should provide new and safe strategies to increase energy generation in I/R hearts and hopefully, minimize surgically induced cardiac I/R injury.

冠状动脉搭桥移植物（CABG）和移植的心脏手术通常涉及心脏 缺血/再灌注（I/R），这导致心肌能源从脂肪酸β-转换 氧化为厌氧性糖酵解。作为适应性，GLUT-4，是葡萄糖转运蛋白的主要同工型 心脏，被招募到心肌细胞表面（也称为肌膜）以吸收葡萄糖并刺激 心脏ATP生产。但是，这种补偿性GLUT4易位不足以满足心脏 葡萄糖对I/R心脏中ATP产生的需求，从而导致能源危机。值得注意的是，最近 多次大型临床试验，涉及将葡萄糖 - 胰岛素 - 钾（GIK）溶液输注到患者中 接受心脏手术尚未显示出任何积极的结果（甚至更糟）。因此，探索如何 迫切需要增强Glut-4的易位和葡萄糖利用率，独立于胰岛素 反I/R触发心脏能量损失。我们最近提出了肿瘤敏感性的新颖发现 Gene 101（TSG101），ESCRT的中心分量（运输所需的内体分类复合物） 机械能够调节动物心脏中膜受体的内体回收。我们的最新 数据进一步表明：1）TSG101在成年小鼠心脏中直接与Glut-4结合； 2）强迫表达 培养的肌细胞中的TSG101导致更高水平的肌膜GLUT-4和改善的细胞存活率 受到缺氧/重氧的挑战； 3）TSG101上调Rab11a和Fip3的表达 （RAB11与家庭相互作用的蛋白3），这是内体回收涉及的两个关键因素。最重要的是，我们的 试验数据还表明，一组自然存在的纳米叶子，外泌体，由骨头释放 骨髓干细胞可以有效地将TSG101传递到心肌细胞中。根据这些初步发现，我们 假设TSG101可以通过促进RAB11A/来减少或预防心脏I/R诱导的能源危机/伤害 FIP3介导的GLUT-4内体回收。用含TSG101的外泌体治疗小鼠心脏 缺血之前或早期再灌注期间可以提升心肌TSG101，从而限制I/R触发 心脏损伤。这里提出的工作将解决三个具体目的：1）定义TSG101在 使用这两种心脏特异性 TSG101过表达和诱导的敲低小鼠模型； 2）确定是否诱导了TSG101 心脏保护取决于Rab11a/Fip3介导的GLUT-4内体回收； 3） 研究TSG101的治疗潜力，以防止/减少I/R诱导的心脏能量应力 和损伤，使用TSG101的外泌体。拟议的研究有望将TSG101识别为 GLUT-4易位的新型调节剂，并作为I/R诱导的能量应力的主要心脏前景器。如果 经过验证，该提案的发现应提供新的安全策略以增加能源的产生 在I/R心脏中，希望最大程度地减少手术诱导的心脏I/R损伤。