Cell cycle activation for cardiac repair

细胞周期激活促进心脏修复

• 批准号: 8676558
• 负责人: LOREN J FIELD
• 金额: $ 37.73万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-15 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8676558
• 关键词: Adult; Amino Acid Substitution; Amino Acids; Animals; BMP10 gene; Biochemical; Cardiac; Cardiac Myocytes; Cell Culture System; Cell Cycle; Cell Cycle Regulation; Chronic; Cicatrix; Complex; Coronary artery; Cyclin D1; Cyclins; Data; Development; Event; Exhibits; Fibrosis; G1/S Checkpoint Pathway; Genetically Modified Animals; Goals; Growth; Heart; Heart Atrium; Heart Hypertrophy; Hematopoietic Stem Cell Mobilization; Hypertrophy; Infarction; Injury; Intervention; Isoproterenol; Large T Antigen; Lead; Ligation; Mediating; Modeling; Molecular Target; Mus; Myocardial; Myocardial Infarction; Myocardium; Natural regeneration; Nature; Nuclear Export; Phosphorylation; Population; Post-Translational Protein Processing; Proteins; Regulatory Pathway; Simian virus 40; Stem cells; TSC2 gene; Tamoxifen; Testing; Therapeutic; Transcriptional Regulation; Transgenic Mice; Transgenic Model; Transplantation; cardiac regeneration; cardiac repair; cyclin D2; cyclin D3; functional restoration; injured; member; mimetics; mouse model; prevent; promoter; reconstitution; regenerative; repaired; research study; response; restoration; transgene expression; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): Although the adult mammalian myocardium exhibits a limited ability to undergo regenerative growth, the intrinsic renewal rate is insufficient to reverse pathophysiologic cardiomyocyte loss. The ability to reconstitute lost cardiac mass in injured hearts could thus be of considerable therapeutic value. One approach to accomplish this entails inducing cell cycle activity in the surviving cardiomyocytes. Preliminary data indicate that targeted expression of cyclin D2, a key member of the regulatory complex which drives transit through the G1/S cell cycle check-point, is sufficient to induce cardiomyocyte cell cycle activity in adult hearts. Moreover, cyclin D2-induced cell cycle activity can reverse structural damage and restore function following myocardial injury. The experiments proposed in this application will further elucidate the mechanism of cyclin D-mediated cardiomyocyte cell cycle regulation. Specific Aim 1 will test the hypothesis that post-translational modification of the D-type cyclins regulates their ability to mediate regenerative growth following myocardial injury. These experiments will utilize newly generated transgenic mice expressing D-type cyclins carrying the relevant phospho-mimetic and non-phosphorylatable amino acid residue substitutions. Other studies in Aim 1 will test the hypothesis that specific phosphorylation events mediate the interaction of D-type cyclins and the p193/Cul7 E3 ubiquitin ligase, and that blocking this interaction enhances cell cycle activity in injured hearts. Experiments proposed in Specific Aim 2 will further test the hypothesis that cyclin D2-mediated cardiomyocyte cell cycle activation can be used to promote myocardial repair in the adult heart. Initial experiments will utilize a conditional transgenic mouse model to determine if cyclin D2 can induce de novo cardiomyocyte proliferation in adult hearts. Other studies are proposed to determine the degree to which pharmacologic interventions which limit adverse post-injury remodeling are able to benefit long-term, cardiomyocyte cell cycle-induced regeneration. Collectively, these studies will help establish the mechanism by which D-type cyclins regulate cardiomyocyte cell cycle entry, and the degree to which targeted expression of cyclin D2 is able to promote myocardial regeneration. The overall goal is to gain an understanding of how cell cycle regulatory pathways can be manipulation to promote the repair of injured hearts. Identification of such molecular targets may ultimately lead to the development of pharmacologic agents to promote regenerative growth in diseased hearts.

描述（由申请人提供）：尽管成年哺乳动物心肌表现出有限的再生生长能力，但内在的更新率不足以逆转病理生理性心肌细胞损失。因此，重建受损心脏中损失的心脏质量的能力可能具有相当大的治疗价值。实现这一目标的一种方法需要诱导存活心肌细胞的细胞周期活动。初步数据表明，细胞周期蛋白 D2（驱动通过 G1/S 细胞周期检查点的调节复合物的关键成员）的靶向表达足以诱导成年心脏中的心肌细胞细胞周期活动。此外，细胞周期蛋白 D2 诱导的细胞周期活性可以逆转心肌损伤后的结构损伤并恢复功能。本申请提出的实验将进一步阐明cyclin D介导的心肌细胞周期调节机制。具体目标 1 将检验 D 型细胞周期蛋白的翻译后修饰调节其介导心肌损伤后再生生长的能力的假设。这些实验将利用新产生的转基因小鼠，其表达携带相关磷酸模拟和不可磷酸化氨基酸残基取代的D型细胞周期蛋白。目标 1 中的其他研究将检验以下假设：特定磷酸化事件介导 D 型细胞周期蛋白和 p193/Cul7 E3 泛素连接酶的相互作用，并且阻断这种相互作用会增强受损心脏中的细胞周期活性。具体目标 2 中提出的实验将进一步检验细胞周期蛋白 D2 介导的心肌细胞周期激活可用于促进成人心脏心肌修复的假设。初步实验将利用条件转基因小鼠模型来确定细胞周期蛋白 D2 是否可以诱导成年心脏中的心肌细胞从头增殖。其他研究旨在确定限制不良损伤后重塑的药物干预措施能够在多大程度上有益于心肌细胞细胞周期诱导的长期再生。总的来说，这些研究将有助于建立D型细胞周期蛋白调节心肌细胞细胞周期进入的机制，以及细胞周期蛋白D2的靶向表达能够在多大程度上促进心肌再生。总体目标是了解如何操纵细胞周期调控途径来促进受损心脏的修复。这些分子靶标的识别最终可能导致药物制剂的开发，以促进患病心脏的再生生长。