Novel Mechanism of RBFox1 Mediated RNA Metabolism in Heart Failure

项目摘要 RNA代谢从合成、加工、翻译到降解，是基因表达的一个有机组成部分 调节，最终决定整体心脏转录组的复杂性和重编程过程中， 心衰RNA结合蛋白是RNA代谢的每一个过程的中心，因此建立了RNA结合蛋白。 它们在心力衰竭发病和进展中的作用应导致新的疾病机制和潜在的 治疗目标PI（陈高博士）的早期报告显示，全球RNA剪接变化 是衰竭心脏中心脏转录组重编程的重要组成部分。此外，这种类似胎儿的RNA- 剪接重编程由RBFox 1调节，RBFox 1是一种肌肉富集的RNA剪接因子。然而，在新的研究中， PI发现心脏RBFox 1基因由于其自身的替代mRNA也编码胞质异构体（RBFox 1c 拼接虽然核RBFox 1 n通过全局替代性调节心肌肥厚反应， 剪接调节，如PI所示，细胞溶质RBFox 1c在心脏病理学中的功能作用 还有待探索在体外和体内的初步研究中，PI发现胞质RBFox 1c在细胞内发挥作用。 应激心脏中促炎基因表达减少在心脏重塑中的关键作用 肌肉细胞。该提案旨在表征RBFox 1c在心脏病中的非典型功能 研究进展，探讨RBFox 1c介导的心脏转录后调控机制。它还 概述了一个广泛的职业发展计划，陈高博士完成博士后培训下， Yi Xing博士的监督，并过渡到一个独立的研究者，配备了独特的 研究技能，科学见解和极具前景的研究管道相结合。 在本提案的K99阶段，PI将描述RBFox 1c对心脏的功能影响 使用遗传小鼠模型和体外培养的心肌细胞的纤维化反应。第二个目标 K99期是确定RBFox 1c介导的炎症基因阻遏的分子机制。 在R 00阶段，PI将表征RBFox 1在心脏生理学中的亚型特异性影响， 使用同种型特异性操作的小鼠模型进行病理性重塑。PI还将探索后- RBFox 1c通过BRIC-Seq、TRAP ribo-seq和 microRNA竞争分析拟议的实验将创造令人兴奋的新机会， 这是心脏生物学中一个重要但尚未充分探索的领域的新发现，新的见解也将填补 目前对病理性心脏重构的发病机制的认识存在重要空白， 应力

PROJECT SUMMARY RNA metabolism from synthesis, processing, translation to degradation is an integrated part of gene regulation that ultimately determines the overall cardiac transcriptome complexity and reprogramming during heart failure. RNA binding proteins are central to every process of RNA metabolism and therefore establishing their roles in the onset and progression of heart failure should lead to novel disease mechanisms and potential therapeutic targets. Earlier reports by the PI (Dr. Chen Gao) have revealed that global RNA splicing changes are important part of cardiac transcriptome reprogramming in failing heart. Furthermore, this fetal-like RNA- splicing reprogramming is regulated by RBFox1, a muscle enriched RNA splicing factor. However, in new study, PI found cardiac RBFox1 gene also encoded a cytosolic isoform (RBFox1c) due to its own alternative mRNA splicing. While the nuclear RBFox1n contributes to cardiac hypertrophic response through global alternative splicing regulation as demonstrated by the PI, the functional role of the cytosolic RBFox1c in cardiac pathology is yet to be explored. In preliminary studies both in vitro and in vivo, PI found the cytosolic RBFox1c played a critical role in cardiac remodeling associated with reduced pro-inflammatory gene expression in stressed heart muscle cells. This proposal aims at characterizing the non-canonical function of RBFox1c in cardiac disease progression and exploring the RBFox1c mediated post-transcriptional regulatory mechanism in heart. It also outlines an extensive career development plan for Dr. Chen Gao to complete postdoctoral training under the supervision of Dr. Yi Xing and to transition into an independent investigator well equipped with a unique combination of research skills, scientific insights and highly promising research pipeline. During the K99 phase of this proposal, the PI will characterize the functional impact of RBFox1c in cardiac fibrotic response using both genetic mouse model and in vitro cultured cardiomyocytes. The second aim of the K99 phase is to determine the molecular mechanism of RBFox1c mediated inflammatory gene repression. During the R00 phase, the PI will characterize isoform specific impact of RBFox1 in cardiac physiology and pathological remodeling using isoform specific manipulated mouse models. The PI will also explore the post- transcriptional regulatory mechanisms mediated by RBFox1c in heart through BRIC-Seq, TRAP ribo-seq and microRNA competition analysis. The proposed experiments will create exciting new opportunities of fundamental discovery in an important yet vastly under-explored area in cardiac biology, and new insight will also fill an important gap in the current understanding to the pathogenesis of cardiac remodeling induced by pathological stress.