The Mechanistic Basis of Cyclin A2-Mediated Cardiac Repair

细胞周期蛋白 A2 介导的心脏修复的机制基础

• 批准号: 7244968
• 负责人: Hina W Chaudhry
• 金额: $ 39.03万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-15 至 2008-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7244968
• 关键词: Adenoviruses; Adult; Arts; Biomedical Engineering; Bone Marrow; Bromodeoxyuridine; Cardiac; Cardiac Myocytes; Cardiac Output; Cardiology; Cardiovascular Diseases; Cell Cycle; Cell Cycle Arrest; Cell Proliferation; Cell Transplantation; Cells; Cellular biology; Characteristics; Cicatrix; Clinical; Coculture Techniques; Complementary DNA; Cyclin-Dependent Kinases; Cyclins; Cytokinesis; Developmental Biology; Embryo; Engineering; Exhibits; Gene Transfer; Genetic; Heart; Heart failure; In Vitro; Infarction; Injection of therapeutic agent; Injury; Investigation; Life; Magnetic Resonance Imaging; Mammalian Cell; Measures; Mediating; Mitosis; Mitotic; Modeling; Monitor; Mus; Muscle Cells; Myocardial Infarction; Myocardium; Myosin Heavy Chains; Natural regeneration; Neonatal; Newts; Operative Surgical Procedures; Organogenesis; Personal Satisfaction; Play; Population; Proliferating; Radiology Specialty; Rattus; Recovery; Reporter Genes; Research Personnel; Research Training; Resources; Role; Side; Silicon Dioxide; Site; Source; Stem cells; Techniques; Testing; Therapeutic; Time; Tissue Engineering; Tissues; Transgenic Mice; Transgenic Organisms; Translations; Transplantation; Ventricular Cardiac alpha-Myosin; Video Microscopy; Viral; base; cell dedifferentiation; cell type; concept; cyclin A2; day; in vivo; insight; interdisciplinary approach; mouse model; novel; postnatal; progenitor; programs; promoter; repaired; response; response to injury; tool; uptake

DESCRIPTION (provided by applicant): The concept of stimulating cardiomyocyte mitotic divisions has dramatic implications for cardiac regeneration and hence, cardiovascular disease. We previously demonstrated for the first time that mammalian cardiomyocyte mitoses can occur postnatally if cyclin A2 is constitutively expressed in cardiomyocytes in a transgenic mouse model. Our more recent results demonstrate that cyclin A2 mediates cardiomyocyte mitoses in the transgenic hearts after myocardial infarction (Ml) is induced, thus repairing the heart with significant recovery of cardiac function when compared with nontransgenic littermate controls. To explore potential clinical translation of these results, we administered cDNA encoding cyclin A2 via de-activated adenovirus to infarcted rats and noted that the rats receiving adeno-cyclin A2 undergo cellular regeneration at the sites of injection and have preserved cardiac output when compared to controls which received empty adenovirus. We hypothesize that there are two potential mechanisms mediating the regeneration we have observed. First, side population (SP) stem cells appear to differentiate into cardiomyocytes in our mouse infarction model, but mitoses in these immature cardiomyocytes are only noted in the transgenic mice, thus possibly uncovering a novel mechanism to induce hyperproliferative progenitor cells. Second, we note a significant increase in expression of phosphohistone H3 and uptake of BrdU in the peri-infarct zone of transgenic mice compared to nontransgenic controls, implicating dedifferentiation and division of adult cardiomyocytes. Utilizing SP cells from transgenic and nontransgenic mice, we propose to explore the first mechanism via in vitro studies of proliferation of SP cell-derived progenitor cells and in vivo studies of SP cell transplantation into a mouse infarction model. Additionally, we will use novel engineered cardiac tissues to evaluate both mechanisms by testing the response to injury of both SP cell-derived progenitors and adult cardiomyocytes from transgenic and nontransgenic mice. The second mechanism will also be examined using viral transfer of cyclin A2 cDNA into adult cardiomyocytes in vitro and the utilization of video microscopy to monitor mitosis and cytokinesis of these cells. These studies are proposed in order to elucidate a more directed path to clinical therapy.

描述（由申请人提供）：刺激心肌细胞有丝分裂的概念对心脏再生和心血管疾病具有重大意义。我们之前首次在转基因小鼠模型中证明，如果细胞周期蛋白A2在心肌细胞中组成性表达，哺乳动物心肌细胞有丝分裂可以在出生后发生。我们最近的研究结果表明，在心肌梗死（Ml）诱导后，细胞周期蛋白A2介导转基因心脏中的心肌细胞有丝分裂，从而修复心脏，与非转基因对照相比，心脏功能显著恢复。为了探索这些结果的潜在临床翻译，我们通过去活化的腺病毒给梗死大鼠注射了编码细胞周期蛋白A2的cDNA，并注意到与接受空腺病毒的对照组相比，接受腺周期蛋白A2的大鼠在注射部位进行了细胞再生，并保留了心输出量。我们假设有两种潜在的机制介导我们观察到的再生。首先，侧群（SP）干细胞在我们的小鼠梗死模型中似乎分化为心肌细胞，但这些未成熟心肌细胞的有丝分裂仅在转基因小鼠中被注意到，因此可能揭示了诱导超增殖祖细胞的新机制。其次，我们注意到，与非转基因对照组相比，转基因小鼠梗死周围区磷酸组蛋白H3的表达和BrdU的摄取显著增加，这与成年心肌细胞的去分化和分裂有关。利用转基因和非转基因小鼠的SP细胞，我们建议通过SP细胞衍生祖细胞的体外增殖研究和SP细胞移植到小鼠梗死模型的体内研究来探索第一种机制。此外，我们将使用新的工程心脏组织，通过测试转基因和非转基因小鼠的SP细胞衍生祖细胞和成年心肌细胞对损伤的反应来评估这两种机制。第二种机制也将通过体外将细胞周期蛋白A2 cDNA病毒转移到成人心肌细胞中，并利用视频显微镜监测这些细胞的有丝分裂和细胞分裂。这些研究是为了阐明更直接的临床治疗途径。