Age Related Change in Mitochondrial Angiotensin System and Mitochondrial Decline

线粒体血管紧张素系统的年龄相关变化和线粒体衰退

• 批准号: 8614142
• 负责人: Peter M. Abadir
• 金额: $ 41.6万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-15 至 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8614142
• 关键词: AGTR2 gene; Affect; Age; Age-Months; Aging; Anabolism; Angiopoietin-2; Angiotensin Receptor; Angiotensins; Animals; Apoptosis; Bioenergetics; Biogenesis; Cardiac; Cardiac Myocytes; Cell Line; Cell membrane; Cells; Confocal Microscopy; Coupled; Development; Disease; Elderly; Electron Microscopy; Energy Metabolism; Equilibrium; Event; Failure; Fluorescent Probes; Foundations; Functional disorder; Future; Generations; Human; Image; In Situ; Intervention; Investigation; Knowledge; Life; Link; Longevity; Losartan; Magnetic Resonance Spectroscopy; Maintenance; Measures; Mediating; Mitochondria; Mitochondrial DNA; Modeling; Mus; Myocardium; Nitric Oxide; Nitrogen; Organism; Outcome; Oxidative Stress; Oxygen; Pathway interactions; Peripheral; Placebos; Play; Process; Production; Proteins; Reactive Oxygen Species; Receptor, Angiotensin, Type 1; Reporter; Reporting; Role; Surface; System; TP53 gene; Testing; Tissues; To specify; Translating; Type 2 Angiotensin II Receptor; Western Blotting; age effect; age related; aged; base; design; improved; in vivo; inhibitor/antagonist; instrument; mitochondrial dysfunction; mouse model; public health relevance; receptor; receptor expression; repaired; theories

Project Abstract Aging and decline in mitochondrial function are closely linked. Key signs of mitochondrial dysfunction include increased generation of reactive oxygen species, fewer ATP molecules produced per O2 consumed, and increased apoptosis. The reduction in ATP translates to lower energy for cellular maintenance processes including mitobiogenesis and turnover. We recently reported the identification of a functional Mitochondrial Angiotensin System (MAS), and found that aging impacts the ratio of key angiotensin type 1 and type 2 receptors in mitochondria (AT1R and AT2R), that AT1R blocking agents may partially reverse these changes and improve mitochondrial function. Importantly, AT1R-/- mice have an enhanced life span by 25%, in part through an increase in mitochondrial numbers. The effects of aging on the expression of mitochondrial (mt) AT1R and mtAT2R and their contribution to age-related changes in mitochondrial dysfunction has not been previously studied. New preliminary evidence suggests that AT1R blockade in old mice may restore the age- related decline in mitochondrial energy production and improve mitophagy efficiency via alterations in p53- inducible protein (MIEAP) expression. We hypothesize that an age-related increase in mtAT1R/AT2R ratio mediates declines in mitochondrial energy metabolism via increased reactive oxygen species (ROS) production and impaired elimination of damaged mitochondria. In order to test this hypothesis we propose a comprehensive study of mtAT1R and mtAT2R, in control and losartan (AT1R blocker) treated, young and aged (38-month old) C57BL/6, AT1-/- and AT2-/- mice. Will use age related cardiac muscle bioenergetics failure as a model to study the impact of changes in mtAT1R and mtAT2R following proposed specific aims: 1. To identify age-related changes in peripheral angiotensin system (PAS) and MAS and their contribution to altered reactive nitrogen/oxygen species ROS/RNS generation, using Q-PCR, western blot, confocal and electron microscopy. Generation of ROS/RNS will be quantified in isolated cardiomyocytes and mitochondria from all our animal groups using specific fluorescent probes. 2. To specify the contribution of age-related changes in PAS and MAS to bioenergetic dysfunction by magnetic resonance spectroscopy and imaging in the cardiac tissue of living animals at baseline and after four weeks of placebo or losartan treatment. MAS contributions to the changes in bioenergetics will studied in isolated cardiac mitochondria from all animal groups. 3. To investigate the role of the PAS and MAS on mitochondrial biogenesis, repair, and elimination by utilizing a cardiac cell line (H9C2) instrumented with a P53 activity reporter to measure the effects of over-expressing AT1R and/or AT2R on MIEAP, oxidative stress, mtDNA damage and mitophagy. Similar outcomes will also be compared between control and LOS treated, young and aged (38-month old) C57BL/6, AT1-/- and AT2-/- mice.

项目摘要 线粒体功能的衰老和下降密切相关。线粒体功能障碍的关键迹象包括 活性氧的产生增加，消耗的O2产生的ATP分子较少，并且 凋亡增加。 ATP的减少转化为细胞维护过程的能量较低 包括有线生物发生和周转。我们最近报告了功能性线粒体的识别 血管紧张素系统（MAS），发现衰老会影响关键血管紧张素1型和类型2的比率 线粒体中的受体（AT1R和AT2R），AT1R阻断剂可能会部分逆转这些变化 并改善线粒体功能。重要的是，AT1R - / - 小鼠的寿命增长了25％，部分 通过线粒体数的增加。衰老对线粒体表达（MT）的影响 AT1R和MTAT2R及其对与年龄相关的线粒体功能障碍变化的贡献尚未 先前研究过。新的初步证据表明，老鼠的AT1R阻断可能会恢复年龄 - 线粒体能量产生的相关下降，并通过改变p53-的改变提高线粒体效率 诱导蛋白（MIEAP）表达。我们假设MTAT1R/AT2R比率增加 通过增加的活性氧（ROS），线粒体能量代谢中介导的下降 生产和消除线粒体受损的消除。为了检验这一假设，我们提出了 MTAT1R和MTAT2R的综合研究，对照和Losartan（AT1R Blocker）处理，年轻和老化 （38个月大的）C57BL/6，AT1 - / - 和AT2 - / - 鼠标。将使用与年龄相关的心肌生物能力失效作为 研究MTAT1R和MTAT2R变化的影响，按照提出的特定目的：1。 外周血管紧张素系统（PAS）和MAS的年龄相关变化及其对改变的贡献 使用Q-PCR，Western印迹，共聚焦和电子，活性氮/氧ROS/RNS生成 显微镜。 ROS/RN的产生将在所有人的孤立心肌细胞和线粒体中进行定量 我们的动物组使用特定的荧光探针。 2。指定与年龄相关的变化的贡献 在PAS和MAS中，通过磁共振光谱和成像在PAS和MAS中进行生物能功能障碍 在基线和安慰剂或氯沙坦治疗四个星期后，活动物的心脏组织。马斯 对所有动物的孤立心脏线粒体的生物能量变化的贡献 组。 3。研究PA和MAS在线粒体生物发生，修复和 通过使用带有p53活动报告的心脏细胞系（H9C2）来消除 过表达AT1R和/或AT2R对MIEAP的影响，氧化应激，mtDNA损伤和线粒体。 在对照和LOS处理，年轻和老年之间也将比较类似的结果（38个月大） C57BL/6，AT1 - / - 和AT2 - / - 小鼠。