Sub-cellular Targeting of Endothelial ROS in Myocardial Ischemia

更新应用是基于新的发现，减少mito-ROS，利用基因

renewal application is based on the novel findings that reduction in mito-ROS, using genetic manipulation and/or nanoparticle drugs, improve survival and proliferation of coronary EC and help recover cardiac function in a post-myocardial infarct (MI) animal model and human atrial tissue. Preliminary findings in the current application demonstrate that reduction of mito-ROS using transgene (MnSOD) and nanodrugs (JP4-039, XJB5-131) induce mitochondrial complex I biogenesis (proteomic and phosphoproteomic data) and oxidative phosphorylation (Ox-Phos) in EC resulting in coronary angiogenesis cardiac function recovery in post-MI heart. This innovative EC, like most tumor cells, utilizes anerobic glycolysis as a major (85%) source of ATP Thus, the shift from less- efficient energy production system glycolysis (2 ATP/glucose molecule), to a more efficient Ox-Phos (34-36 ATP/glucose) may provide critical energy support to EC needed during ischemia (low glucose, oxygen). Here, we propose to examine a novel overarching hypothesis that modulation of mito-ROS improves production, while EC mitochondria are mostly involved in dNTP biosynthesis. Δψm and ‘super-complex’ (SC) formation resulting in efficient electron transport chain (ETC) and Ox-Phos-mediated ATP generation in EC during ischemia. This shift from glycolysis to a more efficient mitochondrial Ox-Phos may provide resilience/survival to coronary EC during ‘energy crisis’ in myocardial ischemia. The therapeutic benefit of intervening on subcellular ROS level will be best realized by specific down regulation of mito-ROS in ECs that have been exposed to ischemia/hypoxia. This hypothesis will be fully tested in vivo using our novel EC-specific transgenic MnSOD (SOD-OE; mitochondrial antioxidant) animals and supported using mitochondria-specific nitroxide and nanoparticle antioxidant in large animal model (swine) and in coronary vessels from CVD patients undergoing cardiac surgery. We propose three Specific Aims. Aim 1: Elucidate the molecular mechanisms by which modulation of mitochondrial ROS protect coronary EC from oxidative stress and induce coronary angiogenesis during myocardial ischemia. Using SOD-VE transgenic animals and myocardial infarct-mimicking (LAD ligation) surgeries, Δψm, super-complex (SC) formation, oxygen consumption rate (OCR) versus extracellular acidification rate (ECAR), ATP synthesis, will be assessed. Aim 2: Determine the effects mitochondria-targeted MnSOD-mimetic (JP4-039, XJB-5-131) nanoparticles on post-infarct vessel density and recovery of cardiac function in mice and on chronic myocardial ischemia in large animals (swine). Aim 3: Elucidate the molecular mechanisms by which mitochondrial antioxidant nanoparticles (JP4-039/XJB-5-131) improve angiogenic potential of human coronary vessels (from cardiac surgery patients) ex vivo. This study using unique animal models, human atrial tissue, and mitochondria- specific antioxidant will provide novel insights into the mechanisms by which mito-ROS can improve EC survival and angiogenesis by recruiting mitochondria as an efficient energy generator during ischemia.