Using miRNA to identify new therapeutic pathways for dilated cardiomyopathy

总结 扩张型心肌病（DCM）相关的心力衰竭是导致死亡的主要原因， 需要战略。超过50个基因的致病性变异导致DCM，但分子机制 对疾病的了解很少。要了解疾病机制并将其转化为 将基础科学转化为治疗策略该项目的目标是确定有针对性的治疗策略 对于DCM。这个目标与我的长期职业目标一致，即成为一名独立的研究人员， 学术实验室，专注于更好地了解人类组织特异性基因转录后调控 表达和开发基于机制的疗法。 我的初步研究结果支持了我的主要假设，即一些微小RNA（miRNA） 在终末期心力衰竭（HF）中上调的心肌细胞对疾病表型发挥代偿作用， 这些miRNAs中的一种具有突变特异性的有益作用，而另一种具有与病因学无关的作用。我 我们建议研究这两种miRNA的作用机制，以确定新的治疗靶点。 在我早期的工作中，我开发了一个实验平台， 诱导多能干细胞衍生的心肌细胞（iPSC-CM）中DCM的浓度。我用这个系统来识别一个 针对DCM特定变体的潜在治疗策略（已发表并获得专利）。我用这个系统在我 该项目的初步工作是鉴定几种改善iPSC-CM收缩表型的miRNA 携带DCM致病性变体，这些变体因其不同的分子病因学而被选择（PLN、RBM20和TNNT2）。作为 据推测，一些miRNAs具有病因特异性的有益作用，而另一些miRNAs则表现出改善作用。 在所有病因中。 我的第一个目标是测试候选miRNA靶点，以确定它们发挥作用的机制。 对iPSC-CM的有益效果。我的第二个目标是确定候选miRNAs的靶基因， 肌节和收缩功能，并在替代的体外模型（工程心脏）中测试它们的作用 组织）和DCM的小鼠模型中。我的第三个目标是检验这样一个假设： 具有突变特异性作用的miRNA和通过以下方式对所有DCM系具有治疗作用的miRNA 比较突变特异性和非特异性治疗性miRNA的靶点。 该项目将扩大我们对心力衰竭机制的理解，并确定新的治疗点。 干预药物开发。本项目还将确定病因特异性和病因无关性 导致DCM的疾病机制，并测试这些差异是否可以用于治疗。的 生成的知识和工具将对DCM社区有价值，并作为我的 随后，在开发个性化的，基于机制的治疗策略的独立工作。

SUMMARY Dilated cardiomyopathy (DCM) associated heart failure is a leading cause of death and new therapeutic strategies are needed. Pathogenic variants in over 50 genes contribute to DCM, but the molecular mechanisms of disease are poorly understood. Much remains to be done to understand disease mechanisms and translate the basic science into therapeutic strategies. The goal of this project is to identify targeted therapeutic strategies for DCM. This goal aligns with my long-term career goal to become an independent researcher leading an academic lab that focuses on better understanding human tissue-specific post-transcriptional regulation of gene expression and developing mechanism-based therapeutics. My primary hypothesis, supported by my preliminary results, is that some of the microRNA (miRNA) upregulated in end stage heart failure (HF) exert a compensatory effect on the disease phenotype and that some of these miRNAs have mutation-specific beneficial effects while others have effects independent of etiology. I propose to study the mechanisms of both kinds of miRNA to identify new therapeutic targets. In my earlier work, I developed an experimental platform to quantify several of the physiological phenotypes of DCM in induced pluripotent stem cell derived cardiomyocytes (iPSC-CMs). I used this system to identify a potential therapeutic strategy (published and patented) for a specific variant of DCM. I used this system in my preliminary work for this project to identify several miRNAs that ameliorate contractile phenotypes in iPSC-CMs carrying DCM causal variants selected for their diverse molecular etiologies (PLN, RBM20, and TNNT2). As hypothesized, some miRNAs had etiology-specific beneficial effects while others demonstrated improvement across all etiologies. My first aim is to test candidate miRNA targets to identify the mechanisms through which they exert the beneficial effect in iPSC-CMs. My second aim is to identify the target genes of candidate miRNAs that regulate sarcomeric and contractile functions and to test their effect in an alternative in vitro model (Engineered Heart Tissues) and in a mouse model of DCM. My third aim is to test the hypothesis that the target space differs for the miRNAs that have a mutation-specific effect and those that have a therapeutic effect on all DCM lines by comparing the targets of mutation-specific and non-specific therapeutic miRNAs. This project will expand our understanding of heart failure mechanisms and identify new points of intervention for drug development. This project will also identify the etiology-specific and etiology-independent disease mechanisms leading to DCM and test whether these differences can be exploited therapeutically. The knowledge and tools generated will be of value to the DCM community and serve as a foundation for my subsequent, independent work in developing personalized, mechanism-based therapeutic strategies.