Molecular mechanism of 4E-binding proteins on heart failure development

4E结合蛋白对心力衰竭发展的分子机制

基本信息

批准号：
8311646
负责人：
YINGJIE CHEN
金额：
$ 37.75万
依托单位：
UNIVERSITY OF MINNESOTA
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-08-05 至 2015-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8311646
关键词：
5&apos Untranslated Regions 7-methylguanosine triphosphate ATP phosphohydrolase Accounting Americas Attenuated Binding Binding Proteins Calcium Cardiac Cardiac Death Cardiac Myocytes Cardiology Cardiovascular Diseases Cessation of life Complex Congestive Heart Failure Data Development Double Effect Functional disorder Gene Deletion Gene Expression Gene Expression Profile Genes Genetic Translation Goals Guanine + Cytosine Composition Heart Heart failure IGFBP2 gene Incidence Infarction Knockout Mice Left Ventricular Remodeling Lung Membrane Proteins Messenger RNA Modeling Molecular Mouse Strains Mus Myocardial Myocardial Infarction Pathway interactions Phosphorylation Play Polyribosomes Protein Biosynthesis Proteins Recruitment Activity Regulation Research Role SERCA2a Sarcoplasmic Reticulum Solid Staging Stress Structure Survival Rate Technology Testing Transfer RNA Transgenic Mice Translation Initiation Translations Work base constriction human FRAP1 protein improved innovation insight knockout gene loss of function mouse development mouse model new therapeutic target novel novel therapeutic intervention overexpression protective effect protein complex protein expression response scaffold

项目摘要

DESCRIPTION (provided by applicant): Gene expression is regulated at multiple levels including the cap-dependent translation of mRNA into proteins. Eukaryotic translation initiation factor4E (eIF4E) binds to the 5'-m7GTP cappresent on all eukaryotic cytoplasmic mRNAs. eIF4E is the central component of the cap-dependent translation initiation complex (eIF4F). The assembly of eIF4F is negatively regulated by 4E-binding proteins (4E-BPs or BPs), which bind eIF4E and block eIF4F assembly to inhibit cap-dependent translation. Three BPs have been identified as BP1, BP2 and BP3 (BP3). We have found that LV BP1 protein expression is greatly increased in advanced congestive heart failure (CHF). We examined the effect of double gene knockout (DKO) of BP1 and BP2 on transverse aortic constriction (TAC) or myocardial infarct induced CHF in mice, and the results demonstrated that BP1/2 DKO profoundly improved the survival rate and LV function in these mice. We also found that BP1/2 DKO increased LV sarcoplasmic reticulum Ca++ ATPase (SERCA2a) protein content ~2.5 fold at the protein level. Based on these preliminary data, the overall goal of this proposal is to determine how enhancing cap-dependent translation initiation by BP1/2 DKO and BP1 KO exert their profound cardiac protective effect against the development of CHF in mice by achieving following research objectives: (i) Determine the consequences of enhancing cap-dependent translational initiation by DKO on stress-induced CHF. Our working hypothesis is that enhancing cap-dependent translation initiation by DKO will protect the heart from TAC or infarct induced CHF; (ii) Identify whether the cardioprotective effect observed in DKO mice is mainly due to loss of function of BP1 or BP2. Our working hypothesis is that the cardiac protective effect is mainly due to the deletion of BP1, and that cardiac myocyte specific BP1 overexpression will cause or exacerbates LV dysfunction; (iii) Identify underlying molecular mechanisms for the cardioprotective effect of enhancing translational initiation by BP1/2 DKO. Our working hypothesis is that BP1/2 DKO will improve the translational efficiency of mRNAs (such as SERCA2a) that have an excessive amount of secondary structure in the 5'-untranslatedregions (5'-UTRs). The project will take advantage of mouse models with targeted disruption of BP1, BP2 and BP1/2, cardiac specific BP1 transgenic mice and of technologies for combined analysis of the transcriptome and translatome. Our research team includes experts in translational control (Dr. Bitterman), molecular cardiology and experimental CHF models (Dr. Chen), polyribosome microarrays (Dr. Bitterman), and membrane protein complexes involved in calcium transport (such as SERCA2a) in cardiac myocytes (Dr. David Thomas). These studies will provide novel insights into the role of cap-dependent translation initiation on the development of CHF. Our preliminary finding indicates that regulation of cap-dependent translation initiation by targeting 4E-binding proteins may be a novel therapeutic approach to treat CHF.

描述（由申请人提供）：基因表达在多个水平上受到调节，包括mRNA到蛋白质的帽依赖性翻译。真核翻译起始因子 4E (eIF4E) 与所有真核细胞质 mRNA 上存在的 5'-m7GTP 结合。 eIF4E 是帽子依赖性翻译起始复合体 (eIF4F) 的核心组成部分。 eIF4F 的组装受到 4E 结合蛋白（4E-BP 或 BP）的负调控，4E 结合蛋白结合 eIF4E 并阻断 eIF4F 组装，从而抑制帽依赖性翻译。三个BP被确定为BP1、BP2和BP3(BP3)。我们发现晚期充血性心力衰竭（CHF）中 LV BP1 蛋白表达大大增加。我们检测了BP1和BP2双基因敲除（DKO）对横主动脉缩窄（TAC）或心肌梗死引起的小鼠CHF的影响，结果表明BP1/2 DKO显着提高了这些小鼠的存活率和左心室功能。我们还发现，BP1/2 DKO 在蛋白质水平上使左室肌浆网 Ca++ ATP 酶 (SERCA2a) 蛋白质含量增加约 2.5 倍。基于这些初步数据，本提案的总体目标是确定如何通过实现以下研究目标来确定 BP1/2 DKO 和 BP1 KO 增强帽依赖性翻译起始如何对小鼠 CHF 的发展发挥深远的心脏保护作用：（ i) 确定 DKO 增强帽依赖性翻译起始对应激诱导的 CHF 的影响。我们的工作假设是，通过 DKO 增强帽依赖性翻译起始将保护心脏免受 TAC 或梗塞诱发的 CHF 的影响； (ii) 确定在 DKO 小鼠中观察到的心脏保护作用是否主要是由于 BP1 或 BP2 功能丧失所致。我们的工作假设是，心脏保护作用主要是由于BP1的缺失，心肌细胞特异性BP1过度表达会导致或加剧左心室功能障碍； (iii) 确定 BP1/2 DKO 增强翻译起始的心脏保护作用的潜在分子机制。我们的工作假设是，BP1/2 DKO 将提高 5'-非翻译区 (5'-UTR) 中具有过量二级结构的 mRNA（例如 SERCA2a）的翻译效率。该项目将利用靶向破坏 BP1、BP2 和 BP1/2 的小鼠模型、心脏特异性 BP1 转基因小鼠以及转录组和翻译组联合分析技术。我们的研究团队包括翻译控制专家（Bitterman 博士）、分子心脏病学和实验性 CHF 模型（陈博士）、多核糖体微阵列（Bitterman 博士）以及参与心肌细胞钙转运的膜蛋白复合物（如 SERCA2a）方面的专家（大卫·托马斯博士）。这些研究将为帽依赖性翻译起始在 CHF 发展中的作用提供新的见解。我们的初步发现表明，通过靶向 4E 结合蛋白来调节帽依赖性翻译起始可能是治疗 CHF 的一种新的治疗方法。