Anchored Kinase Signaling Mechanisms in Cardiac Hypertrophy

心脏肥大中的锚定激酶信号传导机制

• 批准号: 7572931
• 负责人: John D Scott
• 金额: $ 35.1万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2013-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7572931
• 关键词: A kinase anchoring protein; Antibodies; Binding; Biomechanics; Cardiac; Cardiac Myocytes; Catecholamines; Cause of Death; Complex; Cyclic AMP-Dependent Protein Kinases; Disease; Enhancers; Enzymes; Event; Figs - dietary; Funding; Genetic Transcription; HDAC5 gene; Heart; Heart Diseases; Heart Hypertrophy; Heart Valve Diseases; Heart failure; Histone Deacetylase; Human; Hypertension; Hypertrophy; Image; Knock-in Mouse; Measures; Mediating; Molecular; Monitor; Movement; Mus; Muscle Cells; Neonatal; Nuclear; Nuclear Export; Pathway interactions; Pattern; Phosphorylation; Phosphotransferases; Population; Protein Biosynthesis; Protein Kinase C; Proteins; Rattus; Risk Factors; Sarcomeres; Signal Pathway; Signal Transduction; Signaling Protein; Stimulus; Stress; Testing; Time; Tissues; Transcriptional Activation; United States; Western World; Work; citrate carrier; in vivo; member; protein kinase D; protein protein interaction; response; theories

DESCRIPTION (provided by applicant): Heart failure is a complex disorder that is a leading cause of death in the Western world. Approximately 5 million people (2-3 % of the population) are afflicted with this disease in the United States. Increased risk factors such as arterial hypertension and valvular heart diseases place additional biomechanical stress on the heart to induce a cellular response known as pathological cardiomyocyte hypertrophy. Hallmarks of this condition include increased cardiomyocyte size and a greater organization of the sarcomere. At the molecular level, hypertrophic signals such as elevated catecholamines evoke transcriptional activation of the Myocyte Enhancer Factor (MEF2) pathway to change the pattern of protein synthesis. During the past funding period we have begun to decipher some of the protein-protein interactions that contribute to the spatial and temporal modulation of the MEF2 pathway. We have identified an A-Kinase Anchoring protein, called AKAP-Lbc that coordinates the activation and movement of the signaling proteins that initiate MEF2 mediated transcriptional reprogramming events. Our working hypothesis is that AKAP-Lbc synchronizes protein kinase A (PKA) and protein kinase C (PKC) phosphorylation events to facilitate activation of a third enzyme, called protein kinase D (PKD). In turn, PKD phosphorylates the histone deacetylase HDAC5 to promote its nuclear export. Finally, the concomitant reduction in nuclear HDAC activity favors MEF2 transcription and the onset of cardiac hypertrophy. Two specific aims are proposed to test this hypothesis. Specific aim 1: Does AKAP-Lbc organize transcriptional reprogramming? Our preliminary studies show that AKAP-Lbc supports PKD activation and favors nuclear export of HDAC5. Real-time fluorescent imaging will be used to establish if the anchoring protein organizes both signaling events in rat neonatal ventriculocytes (RNV). Related studies will measure MEF2 transcription upon disruption of protein-protein interactions between members of the AKAP/Lbc-PKD/HDAC pathway. Specific aim 2: Does the AKAP-Lbc/PKD/HDAC5 pathway contribute to heart disease? We propose that the AKAP-Lbc/PKD/HDAC5 pathway facilitates the onset of cardiac hypertrophy. Two complementary approaches will test this theory in vivo. Activation state antibodies will monitor the status of the AKAP-Lbc/PKD/HDAC pathway in normal and diseased human heart tissue. Analysis of knock in mice expressing a truncated AKAP-Lbc form that blocks PKD activation will determine if suppression of this signaling pathway protects against certain aspects of cardiac remodeling. Within the United States approximately 5 million people are afflicted with heart failure, a complex disorder that is a leading cause of death. Increased biomechanical stress on the heart induces a cellular response known as pathological cardiomyocyte hypertrophy. We have identified an A-Kinase Anchoring protein, called AKAP-Lbc that is up regulated in hypertrophic cardiomyocytes and that coordinates the activation and movement of signaling proteins upstream of MEF2-mediated transcriptional reprogramming events.

描述（由申请人提供）：心力衰竭是一种复杂的疾病，是西方世界中死亡的主要原因。在美国，大约有500万人（占人口的2-3％）患这种疾病。增加的风险因素（例如动脉高血压和瓣膜心脏病）在心脏上增加了额外的生物力学应力，以诱导称为病理心肌细胞肥大的细胞反应。这种疾病的标志包括增加心肌细胞的大小和更大的肌膜组织。在分子水平上，肥厚的信号（例如升高的儿茶酚胺升高）引起了肌细胞增强子因子（MEF2）途径的转录激活，以改变蛋白质合成的模式。在过去的资金期间，我们开始破译一些有助于MEF2途径的空间和时间调制的蛋白质蛋白质相互作用。我们已经确定了一种称为AKAP-LBC的A-激酶锚定蛋白，该蛋白可以协调启动MEF2介导的转录重编程事件的信号传导蛋白的激活和运动。我们的工作假设是AKAP-LBC同步蛋白激酶A（PKA）和蛋白激酶C（PKC）磷酸化事件，以促进第三个酶的激活，称为蛋白激酶D（PKD）。反过来，PKD磷酸化组蛋白脱乙酰基酶HDAC5以促进其核出口。最后，核HDAC活性的伴随减少有利于MEF2转录和心脏肥大的发作。提出了两个具体目标来检验这一假设。 特定目的1：AKAP-LBC是否会组织转录重编程？我们的初步研究表明，AKAP-LBC支持PKD激活并有利于HDAC5的核出口。实时荧光成像将用于确定锚定蛋白是否组织大鼠新生儿心室（RNV）中的两个信号事件。相关研究将在AKAP/LBC-PKD/HDAC途径成员之间蛋白质 - 蛋白质相互作用的破坏后测量MEF2转录。 特定目标2：AKAP-LBC/PKD/HDAC5途径是否有助于心脏病？我们建议AKAP-LBC/PKD/HDAC5途径有助于心脏肥大的发作。两种互补方法将在体内检验该理论。激活状态抗体将监测正常和患病的人类心脏组织中AKAP-LBC/PKD/HDAC途径的状态。对表达截短的AKAP-LBC形式的小鼠的敲门分析，该敲击会阻断PKD激活，将确定该信号通路的抑制是否可以保护心脏重塑的某些方面。在美国，大约有500万人患有心力衰竭，这是一种复杂的疾病，是死亡的主要原因。对心脏的生物力学应力增加会诱导称为病理心肌细胞肥大的细胞反应。我们已经确定了一种A-Kinase锚定蛋白，称为AKAP-LBC，该蛋白在肥厚的心肌细胞中受到调节，并协调MEF2介导的转录重编程事件上游信号蛋白的激活和运动。