Mitochondrial Modulation of Endothelia Function

内皮功能的线粒体调节

• 批准号: 8505559
• 负责人: John Francis Keaney
• 金额: $ 40.41万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-01-15 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8505559
• 关键词: Acute; Apoptosis; Atherosclerosis; Behavior; Behavior Control; Biogenesis; Blood Clot; Blood Vessels; Blood coagulation; Cell physiology; Cells; Cellular Stress; Characteristics; Communication; Data; Diabetes Mellitus; Diet; Disease; Endothelial Cells; Endothelium; Exhibits; Fatty acid glycerol esters; Functional disorder; Funding; Gene Targeting; Genes; Heme; Hindlimb; Homeostasis; Insulin Resistance; Ischemia; Knock-out; Knockout Mice; Knowledge; Limb structure; Link; Liver; Mediating; Metabolism; Mitochondria; Modeling; Molecular; Morphology; Mus; Muscle; Myocardial Infarction; Neoplasm Metastasis; Obesity; Pancreas; Patients; Phenotype; Principal Investigator; Process; Proteins; Protons; Regulation; Research; Respiration; Role; Signal Transduction; Solid Neoplasm; Stress; Stroke; Superoxides; Testing; Therapeutic; Tissues; Tube; Tumor Angiogenesis; UCP2 protein; Vascular Diseases; Work; Wound Healing; angiogenesis; cell behavior; design; energy balance; in vivo; insight; migration; premature; prevent; programs; public health relevance; research study; response; senescence; tissue repair; tool; tumor

DESCRIPTION (provided by applicant): Mitochondria are known to participate in a host of cellular processes such as apoptosis, heme metabolism, and the regulation of energy balance. Largely due to the mitochondrial impact on energy status, the bulk of most mitochondrial research involved liver, muscle, and pancreatic cells. Since endothelial cells are predominantly glycolytic, little effort was applied to the role of mitochondria in the endothelium, despite recen appreciation that endothelial cells can impact tissue metabolism and homeostasis. In the previous funding period, we found that endothelial PGC-1¿, a transcriptional co-activator for many mitochondrial genes, was critical for endothelial cell stress adaptation. In this application, we present data that uncoupling protein-2 (UCP2), a PGC-1¿ target gene, is particularly important for mitochondrial stress adaptation in the endothelium. In settings of tissue repair or increased fuel utilization, endothelial cells tightly regulate their mitochondrial proton gradient (¿¿) via uncoupling protein-2 (UCP2), in order to prevent "mitochondrial stress" manifest as mitochondrial network fragmentation that promotes endothelial dysfunction. The long-term objective of this investigative program is to understand how mitochondria modulate endothelial function and how we can use this information for new therapies. In order to achieve this objective, we submit as a central hypothesis that endogenous UCP2 functions to prevent "mitochondrial stress" and, as a consequence, UCP2 is a major determinant of endothelial cell function and vascular homeostasis. In order to achieve this project objective, we will first determine the implications of endothelial UCP2 in diet- induced insulin resistance, a condition known to stress mitochondria. Since our preliminary data indicate that UCP2 prevents mitochondrial fragmentation, a known characteristic of obese patients with type 2 (insulin- resistant) diabetes, we will test how UCP2 impacts endothelial function in diet-induced obesity and insulin resistance. We will utilize our newly created UCP2 models with Endothelial Cell-specific KnockOut (ECKOUCP2) or Endothelial Cell-only (ECUCP2) UCP2 expression to determine the functional, morphologic, and molecular implications of endothelial UCP2 with a high-fat diet known to induce obesity and insulin resistance. We will then determine how UCP2 impacts the endothelial responses to stresses such as ischemic revascularization and tumor angiogenesis in vivo. Since our data indicate global UCP2-null mice have impaired angiogenesis with the stress of hindlimb ischemia, we will determine the specific role of UCP2 for endothelial stress in vivo. Accordingly, ECKOUCP2 and ECUCP2 mice will be tested in two models of endothelial stress: a) ischemic revascularization from hind limb ischemia and; b) tumor angiogenesis. With regards to the latter, we will also determine if acute UCP2 inhibition has the therapeutic potential to limit or shrink solid tumors. In addition to the impact on blood vessel formation, we will test endothelial UCP2 for its implications on mitochondrial mass, morphology, and network fragmentation in each model. We will also explore the role of p53 in promoting the endothelial UCP2-null phenotype since UCP2-null endothelium exhibits premature p53-dependent senescence. Finally, we will determine the functional implications of UCP2 in the endothelium. Since our data indicate UCP2 preserves endothelial function by preventing mitochondrial fragmentation, we will determine how UCP2 impacts mitochondrial function and morphology. ECs with manipulated UCP2 status will be tested mitochondrial network fragmentation and the roles of ¿O2--mediated protein damage, mitophagy, mitochondrial biogenesis, and p53 determined in this process. We will then link the mechanism(s) of mitochondrial network fragmentation to endothelial functions relevant to angiogenesis including proliferation, migration, tube formation, and NO¿ bioactivity. The experiments outlined above should provide us with important insight as to how UCP2 controls mitochondrial dynamics and, as a consequence, endothelial function. These insights will inform us as to how the mitochondria impact vascular homeostasis and provide us with the requisite knowledge to utilize mitochondria as a means of manipulating the endothelium in vivo and this knowledge could have wide ranging implications for wound healing, limb ischemia, and tumor metastasis.

描述（由适用提供）：已知线粒体参与许多细胞过程，例如凋亡，血红素代谢和能量平衡的调节。在很大程度上，由于线粒体对能量状态的影响，大多数线粒体研究的大部分涉及肝脏，肌肉和胰腺细胞。由于内皮细胞主要是糖酵解的，因此在线粒体在内皮中的作用几乎没有努力，因此，dospite重新欣赏内皮细胞会影响组织代谢和稳态。在上一个资金期间，我们发现内皮PGC-1是许多线粒体基因的转录共激活因子，对于内皮细胞应激适应至关重要。在此应用程序中 我们提供的数据表明，将蛋白2（UCP2）（pGC-1靶基因）解偶联，对于原始疗法中的线粒体应激适应性尤为重要。在组织修复或增加燃料利用的设置中，内皮细胞通过解开蛋白-2（UCP2）紧密调节其线粒体质子梯度（€»），以防止“线粒体应激”表现为线粒体网络碎片，从而促进内皮不构度。该调查计划的长期目标是了解线粒体如何调节内皮功能以及如何将这些信息用于新疗法。为了实现这一目标，我们认为内源性UCP2功能以防止“线粒体应力”，因此，UCP2是内皮细胞功能和血管稳态的主要决定因素。为了实现这一项目目标，我们将首先确定内皮UCP2在饮食诱导的胰岛素抵抗中的含义，饮食诱导的胰岛素抵抗是应激线粒体的疾病。由于我们的初步数据表明UCP2可防止线粒体碎片化，这是2型肥胖患者（耐胰岛素）糖尿病的已知特征，因此我们将测试UCP2如何影响饮食诱导的肥胖和胰岛素耐药性中内皮功能。我们将利用我们新创建的UCP2模型，具有内皮细胞特异性敲除（ECKOUCP2）或仅内皮细胞（ECUCP2）UCP2表达表达来确定内皮UCP2的功能，形态和分子含义，并具有高脂饮食，并具有诱导obesity和胰岛素的高脂肪饮食。然后，我们将确定UCP2如何影响对压力的内皮反应，例如缺血性血运重建和体内肿瘤血管生成。由于我们的数据表明全球UCP2-NULL小鼠与后肢缺血的应激受损，因此我们将确定UCP2在体内内皮应激中的特定作用。根据，ECKOUCP2和ECUCP2小鼠将在两种内皮压力模型中进行测试：a）后肢缺血的缺血血流量，并且； b）肿瘤血管生成。关于后者，我们还将确定急性UCP2抑制是否具有限制或收缩实体瘤的治疗潜力。除了对血管形成的影响外，我们还将测试内皮UCP2在每个模型中对线粒体质量，形态和网络碎片的影响。我们还将探讨p53在促进内皮UCP2-NULL表型中的作用，因为UCP2-NULL内皮表现出早产p53依赖性感应。最后，我们将确定UCP2在内皮中的功能含义。由于我们的数据表明UCP2通过预防线粒体碎片来保留内皮功能，因此我们将确定UCP2如何影响线粒体功能和形态。具有操纵UCP2状态的EC将测试线粒体网络碎片，以及在此过程中确定的O2介导的蛋白损伤，线粒体生物发生和p53的作用。然后，我们将将线粒体网络碎片的机制与与血管生成有关的内皮功能（包括增殖，迁移，管形成和NOCEBIOACTIVITY）联系起来。上面概述的实验应为我们提供有关UCP2如何控制线粒体动力学以及结果是内皮功能的重要见解。这些见解将告知我们线粒体如何影响血管稳态，并为我们提供必要的知识，以利用线粒体作为操纵体内内皮的一种手段，并且这种知识可能对伤口愈合，LIMB缺血和肿瘤转移具有广泛的影响。