Role of mRNA-binding protein tristetraprolin in cardiac mRNA regulation and the development of heart failure

mRNA结合蛋白tristetraprolin在心脏mRNA调节和心力衰竭发展中的作用

基本信息

批准号：
10365412
负责人：
Hossein Ardehali
金额：
$ 57.28万
依托单位：
NORTHWESTERN UNIVERSITY AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-12-15 至 2025-11-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10365412
关键词：
3&apos Untranslated Regions Acids Address Animal Model Binding Binding Proteins Branched-Chain Amino Acids Cardiac Cardiac Myocytes Catabolism Cell physiology Clinical Co-Immunoprecipitations Collaborations Complex Data Defect Developed Countries Disease Elements Epidemic Fatty Acids Genes Genetic study Health Heart Heart failure Homeostasis Human Impairment Inflammation Inflammatory Insulin Ischemia Keto Acids Knock-out Knockout Mice Knowledge Lead Link Lipids Measures Mediating Messenger RNA Metabolic syndrome Metabolism Modeling Mus Oxidoreductase PPAR alpha Pathology Pathway interactions Perfusion Pharmaceutical Preparations Process Protein phosphatase Proteins RNA Regulation Role Stress System TIS11 protein TNF gene Testing Tissues Zinc Fingers amino acid metabolism branched chain alpha ketoacid dehydrogenase cardiogenesis clinically relevant constriction drug discovery fatty acid metabolism fatty acid oxidation heart function heart metabolism heart preservation improved induced pluripotent stem cell knock-down lipid metabolism mRNA Transcript Degradation new therapeutic target novel oxidation preservation pressure response side effect systemic inflammatory response uptake

项目摘要

Heart failure (HF) is a major health epidemic in developed countries, however, its underlying pathology is not well characterized. Tristetraprolin (TTP) is a tandem zinc finger protein that binds to AU-rich elements (ARE) in the 3’-untranslated region (UTR) of target mRNA molecules, and induces their degradation. Global TTP knockout (KO) mice display systemic inflammation, since TNFα mRNA is normally degraded by TTP, and deletion of TTP leads to elevated TNFα levels. Thus, very few studies have assessed the role of TTP in metabolism despite its original discovery as an insulin-inducible gene, and genetic studies linking TTP to metabolic syndrome. We are addressing this fundamental gap in knowledge, and our strong preliminary data suggest critical activities by TTP in cardiac metabolism and the development of HF. Specifically, we have shown that TTP inhibits fatty acid (FA) and branched-chain amino acid (BCAA) metabolism (independent of its effects on inflammation), and reduces the mRNA levels of key proteins in these processes, i.e., peroxisome proliferator-activated receptor (PPAR)-α and branched-chain α–ketoacid acid dehydrogenase complex (BCKDC)-E2 subunits. The central hypothesis of this proposal is that TTP inhibits cardiac FA and BCAA metabolism by binding to and degrading PPARα and BCKDC-E2 mRNAs, and that TTP exacerbates the development of HF by impairing FA and BCAA metabolism. In Aim 1, we will assess whether TTP inhibits cardiac FA metabolism by binding to PPARα mRNA and promoting its degradation. We will assess whether TTP binds to PPARα mRNA by performing RNA co-immunopreciptation (co-IP) and deletion studies of PPARα 3’-UTR AREs. We will also measure FA uptake and metabolism in the hearts from cardiac-specific TTP KO (csTTP-KO) mice, and will determine whether these changes are through PPARα using TTP/PPARα double KO mice. In Aim 2, we will determine whether TTP decreases BCAA catabolism through binding and degradation of BCKDC-E2 mRNA. We will first determine whether TTP binds BCKDC-E2 mRNA by performing RNA co-IP and deletion studies on BCKDC-E2 3’-UTR AREs. We will also measure BCAA levels and BCKDC activity in heart tissue from csTTP-KO mice. To demonstrate whether the reduction in BCAA catabolism with TTP KO is through BCKDC-E2, we will perform similar studies with knockdown of TTP and BCKDC-E2. In Aim 3, we will determine whether TTP has detrimental effects on the heart under stress conditions, and whether this depends upon impaired FA and BCAA metabolism. We will subject csTTP-KO mice to pressure overload and ischemia, then assess their cardiac function and metabolism. To determine the role of PPARα and BCKDC in this process, we will use csTTP/PPARα double KO mice and will cross csTTP-KO with protein phosphatase 2Cm KO mice (which have reduced BCKDC activity), and assess cardiac response to stress. We will also show our studies to develop novel drugs that target TTP without inducing inflammation, providing potential clinical implications for Aim 3. These studies will improve our understanding of cardiac metabolism, and may lead to new avenues for treatment of HF.

心力衰竭（HF）是发达国家的主要健康流行病，但是，其潜在的病理不是特征很好。 Tristetraprolin（TTP）是一种串联锌指蛋白，与富含Au的元素结合（IS）靶mRNA分子的3'-非翻译区（UTR），并诱导其降解。全球TTP淘汰赛（KO）小鼠表现出全身性炎症，因为TNFαmRNA通常通过TTP降解，而TTP的缺失导致TNFα水平升高。这很少有研究评估了TTP在代谢目的地的作用原始发现是一种胰岛素诱导的基因，以及将TTP与代谢综合征联系起来的遗传研究。我们是解决知识的这一基本差距，我们的强大初步数据表明了TTP的关键活动在心脏代谢和HF的发展中。具体而言，我们已经表明TTP抑制脂肪酸（FA）和分支链氨基酸（BCAA）代谢（与炎症的影响无关），并减少在这些过程中，关键蛋白的mRNA水平，即过氧化物组增殖受体（PPAR）-α 和分支链α-酮酸脱氢酶复合物（BCKDC）-e2亚基。中心假设该建议是TTP通过结合和退化来抑制心脏FA和BCAA代谢 PPARα和BCKDC-E2 mRNA，TTP通过损害FA和 BCAA代谢。在AIM 1中，我们将评估TTP是否通过与PPARα结合来抑制心脏FA代谢 mRNA并促进其降解。我们将通过执行RNA评估TTP是否与PPARαMRNA结合 PPARα3'-UTR ARES的共免疫沉淀（CO-IP）和缺失研究。我们还将测量FA的吸收和心脏特异性TTP KO（CSTTP-KO）小鼠的心脏中的代谢，并将确定这些是否是否使用TTP/PPARα双KO小鼠通过PPARα进行变化。在AIM 2中，我们将确定TTP是否通过BCKDC-E2 mRNA的结合和降解来减少BCAA分解代谢。我们将首先确定 TTP是否通过对BCKDC-E2 3'-UTR进行RNA Co-IP和缺失研究来结合BCKDC-E2 mRNA Ares。我们还将测量来自CSTTP-KO小鼠心脏组织中的BCAA水平和BCKDC活性。到证明与TTP KO的BCAA分解代谢是否通过BCKDC-E2，我们将执行与TTP和BCKDC-E2敲低的类似研究。在AIM 3中，我们将确定TTP是否确定在压力条件下对心脏的影响，以及这是否取决于FA和BCAA代谢受损。我们将使CSTTP-KO小鼠施加压力超负荷和缺血，然后评估其心脏功能和代谢。为了确定PPARα和BCKDC在此过程中的作用，我们将使用CSTTP/PPARα双KO 小鼠并将与CSTTP-KO与蛋白质磷酸酶2cm KO小鼠（降低BCKDC活性），跨CSTTP-KO，并评估对压力的心脏反应。我们还将展示我们的研究以开发针对TTP的新型药物没有诱导的注射，为目标3提供潜在的临床意义。这些研究将改善我们的了解心脏代谢，并可能导致治疗HF的新途径。