Hsp90, NOS3 and Cardioprotection

Hsp90、NOS3 和心脏保护

• 批准号: 7047708
• 负责人: Yang Shi
• 金额: $ 37.1万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7047708
• 关键词: aminohydrolases; cardiovascular disorder prevention; cytoprotection; disease /disorder model; enzyme activity; enzyme inhibitors; genetic strain; guanosine triphosphate; heart pharmacology; heat shock proteins; laboratory rat; molecular site; myocardial ischemia /hypoxia; nitric oxide; nitric oxide synthase; oxygen transport; phosphorylation; protein protein interaction; recombinant proteins; spontaneous hypertensive rat; tetrahydrobiopterin

DESCRIPTION (provided by applicant): Our understanding of the mechanisms mediating resistance to myocardial ischemia remains unclear. To determine mechanisms for increasing resistance to ischemia, we subjected hearts from Brown Norway (BN/Mcw) and Dahl S (SS/Mcw) rats to global ischemia. Hearts from BN/Mcw rats were more resistant to ischemia than hearts from SS/Mcw rats. Examination of cellular mechanisms revealed that although hearts from both strains exhibited the same levels of endothelial nitric oxide synthase (NOS3) and heat shock protein 90 (hsp90) expression, hearts from BN/Mcw rats generated more nitric oxide (.NO) and less superoxide anion (02.-) than hearts from SS/Mcw rats. Basic proteomic studies revealed that the shift in the balance in NO and O2.- production toward NO in the BN/Mcw hearts was due, at least in part, to altered heat shock protein 90 (hsp90) association with NOS3 and possibly, with GTP cyclohydrolase I (GTPCH-I). We observed that hsp90 association with NOS3 in BN/Mcw hearts was increased nearly 2-fold compared to association in SS/Mcw hearts; and that total biopterin, an analytical index of tetrahydrobiopterin (BH4) was increased in BN/Mcw hearts by 80%. Total biopterin concentrations in hearts from BN/Mcw rats directly correlated with a 70% increase in GTPCH-I protein levels and interestingly, a 2.2-fold increase in association of GTPCH-I with hsp90 compared to the levels in SS/Mcw hearts. These data suggest that hsp90-dependent chaperone activity may play a critical role in mechanisms governing NOS3 function that many consider to be two independent hypotheses: 1) hsp90-dependent signaling modulates NOS3 generation of .NO (coupled activity) and O2.- (uncoupled activity); and, 2) modulation of BH4 levels, which in turn, regulate coupled and uncoupled NOS3 activity. The overall objective of this proposal is to determine the cellular, molecular and enzymatic mechanisms by which hearts from BN/Mcw rats are more resistant to ischemia than hearts from SS/Mcw rats. By elucidating these pathways, findings from this proposal will provide new, fundamental insight into how hsp90 chaperone activity increases NOS3 .NO generation to increase resistance to ischemia. Observations from these studies may actually unify two hypotheses that many consider competing hypotheses in cardiovascular physiology and may also lead to the development of new strategies for treating ischemic heart disease.

描述（由申请人提供）：我们对介导对心肌缺血抗性的机制的理解尚不清楚。为了确定增加对缺血性抗性的机制，我们从北挪威（BN/MCW）和DAHL S（SS/MCW）大鼠的心脏对全球缺血的心脏进行了对象。与SS/MCW大鼠的心脏相比，来自BN/MCW大鼠的心脏对缺血更具抵抗力。对细胞机制的检查表明，尽管两种菌株的心脏表现出相同水平的内皮一氧化氮合酶（NOS3）和热激蛋白90（HSP90）的表达，但来自BN/MCW大鼠的心脏产生了更多的一氧化氮（.no），而不是超级氧化物阴离子（02.-）（02.-）（02.-22.-）。基本的蛋白质组学研究表明，NO和O2的平衡的变化至少部分是由于热休克蛋白90（HSP90）与NOS3的关联，以及可能与GTP环氧基水解酶I（GTPCH-I）的关联。我们观察到，与SS/MCW心脏的关联相比，BN/MCW心脏中的HSP90与NOS3的关联近2倍。 BN/MCW心脏中，总生物蛋白是四氢无菌蛋白酶（BH4）的分析指数，增加了80％。来自BN/MCW大鼠心脏中的总生物蛋白浓度直接与GTPCH-I蛋白水平增加70％，有趣的是，与SS/MCW心脏的水平相比，GTPCH-I与HSP90的缔合增加了2.2倍。这些数据表明，HSP90依赖性的伴侣活性在管理NOS3功能的机制中起着至关重要的作用，许多人认为这是两个独立的假设：1）HSP90依赖性信号调节NOS3的NOS3生成.NO（耦合活性）和O2.2.-（UNOFEPPLECTED活性）； 2）BH4水平的调节，进而调节耦合和未耦合的NOS3活性。该提案的总体目的是确定BN/MCW大鼠的心脏对缺血的耐药性比SS/MCW大鼠的心脏更具抵抗力的细胞，分子和酶促机制。通过阐明这些途径，该提案的发现将提供有关HSP90伴侣活动如何增加NOS3的新的，基本的见解。没有生成以增加对缺血性的抗性。这些研究的观察结果实际上可能统一了两个假设，许多假设考虑了心血管生理学中的竞争假设，并且也可能导致发展治疗缺血性心脏病的新策略。