Mitochondrial Dysfunction in heart Failure

本项目的中心目标是确定心力衰竭（HF）中心肌生物能量衰竭的机制 并设计针对改善线粒体能量产生的治疗策略。我们最近发现了一个 中度严重犬心脏线粒体氧化磷酸化（OXPHOS）显著降低 微代谢诱导的HF。线粒体的缺陷不在于个体的总量和活性 电子传递链复合物，但在它们的组装在超复合物（crossomes）。络合物IV不 掺入的丝氨酸蛋白酶体中丝氨酸和苏氨酸磷酸化的含量增加， 与对照组相比，HF分离的线粒体。我们假设HF诱导的肾上腺素能 刺激增加了C3-β胞质cAMP，其通过以下途径转运到线粒体膜间隙中： 线粒体外膜电压依赖性阴离子通道（VDAC），并激活线粒体 cAMP依赖性激酶（mtPKA）。mt PKA诱导的暴露于基质的丝氨酸和苏氨酸的磷酸化 细胞色素c氧化酶（考克斯）亚基的残基损害考克斯掺入超复合物， 减少心肌线粒体的OXPHOS。络合物I和III不 掺入到胞内酶体中促进电子泄漏并产生超氧化物， 线粒体基质和肌原纤维蛋白的修饰，具有降低的收缩性能。 实验将在建立良好的HF犬冠状动脉微栓塞模型中进行， 转基因小鼠和培养的细胞。具体目标1将研究线粒体膜蛋白酶体组织， 中度和重度犬HF中的OXPHOS、ATP产生和ROS产生。具体目标2将 确定肾上腺素能刺激在破坏HF中线粒体膜蛋白酶体组装中的作用。 具体目标3将描述负责将肾上腺素能信号翻译成 线粒体改变具体目标4将鉴定cAMP诱导的线粒体靶点。 磷酸化及其功能后果。具体目标5提出了一种合理的治疗方法， 靶向cAMP/mtPKA信号传导的策略，试图阻止线粒体ROS的产生， 相关性（参见说明）：

The central goal of this project is to define the mechanism of myocardial bioenergetic failure in heart failure (HF) and design therapeutic strategies targeted to improve mitochondrial energy production. We recently found a dramatic decrease in oxidative phosphorylation (OXPHOS) of heart mitochondria in canine moderate severity micromebolism-induced HF. The mitochondrial defect does not lie in the total amount and activity of individual electron transport chain complexes but in their assembly in supercomplexes (respirasomes). Complex IV not incorporated in respirasomes contains an increased content of serine and threonine phosphorylation in mitochodria isolated from HF compared with the control. We hypothesize that HF-induced adrenergic stimulation increases C3^osolic cAMP which is transported into the mitochondrial intermembrane space through the mitochondrial outer membrane voltage-dependent anion channel (VDAC) and activates the mitochondrial cAMP dependent kinase (mtPKA). mt PKA-induced phosphorylation of matrix-exposed serine and threonine residues of cytochrome c oxidase (COX) subunits impairs the incorporation of COX into supercomplexes, reduces the amount of fijnctional respirasomes, and decreases OXPHOS of heart mitochondria. Complexes I and III not incorporated in respirasomes facilitate electron leakage and produce superoxide, which causes oxidative modifications of both mitochondrial matrix and myofibrillar proteins, with decreased contractile performance. Experiments will be performed in the well established canine coronary microembolization model ofHF, transgenic mice and cultured cells. Specific aim 1 wil investigate mitochondrial respirasome organization, OXPHOS, ATP production, and ROS generation in moderate severity and severe canine HF. Specific aim 2 will identify the role of the adrenergic stimulation in disruption of the assembly of mitochondrial respirasomes in HF. Specific aim 3 will delineate the mechanistic pathway responsible for the translation of the adrenergic signal into mitochondrial alterations. Specific aim 4 will identify the specific mitochondrial targets for the cAMP-induced phosphorylation and their functional consequences. Specific aim 5 proposes a rational approach for therapeutic strategies that targets cAMP/mtPKA signaling with the attempt to prevent mitochondrial ROS generation, RELEVANCE (See instructions):