Effect of CTHRC1 on endothelial cell survival after acute ischemia

CTHRC1对急性缺血后内皮细胞存活的影响

• 批准号: 9885606
• 负责人: VOLKHARD LINDNER
• 金额: $ 53.46万
• 依托单位: MAINEHEALTH
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-20 至 2023-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9885606
• 关键词: Acute; Address; Adult; Apoptosis; Apoptotic; Blood; Blood Circulation; Body Composition; Brain; Cardiac; Cardiac Myocytes; Cardiovascular Diseases; Cardiovascular system; Cell Survival; Cells; Cellular Assay; Cellular Metabolic Process; Cellular Stress; Collagen; Coronary artery; Data; Development; Endothelial Cells; Energy Metabolism; Environment; Event; Fibroblasts; Foundations; Genetic; Glucose; Glycolysis; Goals; Heart; Heart Arrest; Hormones; Hour; Human; In Vitro; Individual; Inflammation; Ischemia; Knockout Mice; Laboratories; Ligation; Mediator of activation protein; Metabolic; Metabolism; Minority; Mitochondria; Modeling; Molecular; Monitor; Mouse Strains; Mus; Myocardial Infarction; Myocardial Ischemia; Outcome; Oxygen; Pathway interactions; Patients; Pattern; Perfusion; Pericytes; Phase; Phenotype; Physical activity; Physiological; Plasma; Production; Publishing; Rattus; Regulatory Pathway; Respiration; Rest; Role; Sampling; Signal Transduction; Site; Source; Stress; Survival Rate; Testing; Time; Tissues; Transgenic Mice; Transgenic Organisms; Up-Regulation; Wild Type Mouse; angiogenesis; bone; cardiovascular health; cell type; coronary artery occlusion; experience; human subject; improved outcome; in vivo; injured; injury and repair; interstitial cell; ischemic injury; mortality; mouse model; novel; novel therapeutic intervention; overexpression; predictive modeling; promoter; protective effect; repaired; respiratory; response; tissue injury; triple helix

Abstract In previous studies we have demonstrated that CTHRC1 (Collagen Triple Helix Repeat Containing 1), a factor discovered in our laboratory, is constitutively expressed only in brain and bone and not in other tissues during adulthood. However, CTHRC1 is highly expressed in activated fibroblasts and interstitial cells of tissues undergoing remodeling and repair. We discovered that CTHRC1 is a circulating factor but only approximately 30% of healthy human subjects have detectable levels of CTHRC1 in plasma, ranging in concentration from low pg/ml to almost 100ng/ml. Similar to most humans, circulating levels of CTHRC1 are not detectable in mice and rats and forced transgenic overexpression of CTHRC1 under Pdgfrb promoter control does also not result in detectable CTHRC1 plasma levels. Thus there are two pools of CTHRC1; one that is generated locally in tissues undergoing repair requiring >48 hours to be available, and a second pool of circulating CTHRC1 available at all times and found only in a minority of human subjects. The significance of circulating CTHRC1 for the cardiovascular system became apparent when we obtained plasma samples from patients experiencing cardiac arrest, a condition with approximately 50% mortality. High CTHRC1 levels (≥0.75ng/ml) are associated with substantially higher survival rates in humans experiencing cardiac arrest. While CTHRC1 is not expressed in the adult heart, it is highly induced in fibroblasts activated in response to myocardial infarction. To test the role of CTHRC1 in acute ischemic injury, we performed coronary artery ligation in Cthrc1 null mice and Cthrc1 transgenic mice on the Cthrc1 null background with physiologically relevant CTHRC1 plasma levels in the ng/ml range found in humans. Strikingly, 70% of Cthrc1 null mice died 3-4 days after the ischemic injury whereas all transgenic mice survived. With the goal of identifying the mechanism for this dramatic finding we performed in vitro studies and found that CTHRC1 promotes cell survival in variety of cell types including endothelial cells. Complete metabolic monitoring revealed that Cthrc1 null mice have increased energy expenditure at rest and analysis of cell metabolism in vitro revealed that in the presence of CTHRC1 mitochondrial respiration is significantly increased whereas glycolysis is reduced, leading us to hypothesize that CTHRC1 functions as a mediator of metabolic efficiency. Overall, this proposal will test the hypothesis that CTHRC1 functions as a mediator of cell survival under conditions of cell stress by increasing metabolic efficiency, which in turn protects from the deadly consequences of acute ischemic injury. We will determine if increasing circulating- or CTHRC1 tissue levels provides cardiovascular protection by limiting the deleterious consequences of myocardial ischemia. Using genetic mouse models and in vitro approaches the underlying mechanism of action will be identified, and this will provide the foundation for novel therapeutic approaches to improve outcomes of acute ischemic conditions.

抽象的 在先前的研究中，我们已经证明CTHRC1（胶原三螺旋均重复1），一个因素 在我们的实验室中发现，仅在大脑和骨骼中始终表达 成年。但是，CTHRC1在活化的成纤维细胞和组织的间质细胞中高度表达 进行改建和维修。我们发现CTHRC1是一个循环因素，但仅大约 30％的健康人受试者在血浆中具有可检测到的CTHRC1水平，浓度从 低pg/ml至接近100ng/ml。与大多数人类相似，小鼠循环水平无法检测到 在PDGFRB启动子控制下，CTHRC1的大鼠和强迫转基因过表达也不会导致 在可检测的CTHRC1血浆水平中。有两个CTHRC1池；一个在本地生成的 进行维修的组织需要> 48小时才能可用，第二个循环的CTHRC1池 始终可用，仅在少数人类受试者中找到。循环CTHRC1的重要性 当我们从经历的患者那里获得血浆样本时，心血管系统变得显而易见 心脏骤停，死亡率约为50％。高CTHRC1水平（≥0.75ng/ml）是相关的 人类经历心脏骤停的生存率较高。而CTHRC1未表达 在成年心脏中，它在响应心肌梗死的成纤维细胞中高度诱导。测试 CTHRC1在急性缺血性损伤中的作用，我们在CTHRC1 NULL小鼠和CTHRC1中进行了冠状动脉连接 CTHRC1无效背景的转基因小鼠具有物理相关的CTHRC1等离子体水平 在人类中发现的Ng/mL范围。令人惊讶的是，缺血性损伤后3-4天死亡，有70％的CTHRC1无效小鼠死亡 而所有转基因小鼠都幸存下来。为了确定这一戏剧性发现的机制 进行了体外研究，发现CTHRC1促进了各种细胞类型的细胞存活 内皮细胞。完整的代谢监测表明，CTHRC1无效小鼠的能量增加 休息时的支出和体外细胞代谢的分析表明，在存在CTHRC1的情况下 线粒体呼吸显着增加，而糖酵解则减少，导致我们假设 该CTHRC1充当代谢效率的介体。总体而言，该提议将检验以下假设。 CTHRC1在细胞应激条件下通过增加代谢而充当细胞存活的介体 效率又可以保护急性缺血性损伤的致命后果。我们将确定是否 增加循环或CTHRC1组织水平通过限制有害的可提供心血管保护 心肌缺血的后果。使用遗传小鼠模型并在体外接近基础 将确定作用机理，这将为新的治疗方法提供基础 改善急性缺血状况的预后。