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

• 批准号: 8461159
• 负责人: YINGJIE CHEN
• 金额: $ 35.94万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 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/8461159
• 关键词: 5' 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

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）：基因表达在多个层次上受到调节，包括mRNA向蛋白质的帽依赖性翻译。真核翻译起始因子4E（EIF4E）与所有真核生物细胞质mRNA上的5'-M7GTP结合。 EIF4E是CAP依赖性翻译起始复合物（EIF4F）的核心组成部分。 EIF4F的组装受4E结合蛋白（4E-BPS或BP）的负调节，该蛋白（4E-BPS或BPS）结合EIF4E并阻止EIF4F组装以抑制限制帽依赖性翻译。三个BP已被确定为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。我们检查了BP1和BP2的双基因敲除（DKO）对小鼠横向主动脉凹陷（TAC）或心肌梗死诱导的CHF的影响，结果表明BP1/2 DKO在这些小鼠中深刻提高了BP1/2 DKO的生存率和LV功能。我们还发现，BP1/2 DKO在蛋白质水平上增加了LV肌浆网Ca ++ ATPase（SERCA2A）蛋白含量〜2.5倍。基于这些初步数据，该提案的总体目标是确定如何通过BP1/2 DKO和BP1 KO增强依赖帽依赖性的翻译启动，从而发挥了深远的心脏保护作用，以抵抗小鼠的CHF发展，通过实现研究目标来实现chf的发展：（i）确定依赖型依赖性的依赖性cap依赖性转化依赖于压力的dko对压力依赖的后果。我们的工作假设是，增强DKO的帽依赖性翻译启动将保护心脏免受TAC或梗塞诱导的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功能的丧失。我们的工作假设是，心脏保护作用主要是由于BP1的删除，而心肌细胞特异性BP1过表达会导致或加剧LV功能障碍。 （iii）确定基本的分子机制，以增强BP1/2 DKO转化起始的心脏保护作用。我们的工作假设是，BP1/2 DKO将提高mRNA（例如SERCA2A）的翻译效率，这些效率（例如SERCA2A）在5'-非翻译区（5'-utrs）中具有过高的二级结构。该项目将利用具有靶向破坏BP1，BP2和BP1/2的小鼠模型，心脏特异性BP1转基因小鼠以及技术的结合分析转录组和翻译组。我们的研究团队包括转化控制的专家（Bitterman博士），分子心脏病学和实验CHF模型（Chen博士），多核糖体微阵列（Bitterman博士）和参与心脏心肌钙转运（例如SERCA2A）的膜蛋白综合体（David Thomas博士）。这些研究将提供有关依赖帽依赖性翻译启动对CHF发展的作用的新见解。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的一种新型治疗方法。