Mechanisms of microRNA dysregulation in Fragile X Syndrome

脆性 X 综合征中 microRNA 失调的机制

• 批准号: 10825482
• 负责人: Adam Kosti
• 金额: $ 6.95万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-13 至 2026-09-12
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10825482
• 关键词: Electrocardiogram; Fragile X Syndrome; Ice; MicroRNAs; ferryl iron

PROJECT SUMMARY: Fragile X Syndrome (FXS) is the most common form of both inherited intellectual disability and monogenic cause of autism. It is caused by the loss of Fragile X Messenger Ribonucleoprotein 1 (FMR1/FMRP) protein. FMRP, an RNA-binding protein, regulates target mRNAs through a variety of modes, such as controlling mRNA localization, stabilization, editing, and/or translation. Translational repression by FMRP is especially important in neuronal processes, where protein synthesis must be controlled in an orderly fashion. In the absence of FMRP, translational control is disrupted resulting in the over-production of dendritic proteins contributing to the FXS neuron phenotype of immature spines and hyperexcitability. Proper translation regulation by FMRP requires microRNAs (miRNAs) and the RNA-induced silencing complex {RISC). The RISC regulates gene expression post-transcriptionally by utilizing base matching between a miRNA and target mRNA, which allows for specific recognition of target mRNAs. It has been shown that miRNAs are dysregulated in several FXS models; however, no study has unbiasedly characterized the complete mi RNA landscape in human FXS models. Another unaddressed aspect of FMRP-miRNA mediated gene regulation is whether the interactions are always cooperative. Recent studies have highlighted an underappreciated role for FMRP in enhancing translation rather than suppressing it. Thus, I hypothesize that FMRP loss alters the miRNA landscape, and that FMRP not only coordinates miRNA-mediated repression, but in some cases antagonizes the miRNA-RISC machinery to protect transcripts from improper regulation. To test my hypotheses, I will conduct experiments aimed at the following goals: 1.) Test whether loss of FMRP alters global neuron miRNA expression patterns, miRNA incorporation into the RISC, and localization of miRNAs to neuronal processes. 2.) Determine whether FMRP-microRNA interactions regulate global and/or local translation of FMRP target mRNAs. To accomplish these aims, I will require new training in induced-pluripotent stem cell cultures, neural organoids, and microscopy. My sponsor, Dr. Gary Bassell, has expertise in these methods, and the scientific community of Emory University School of Medicine will offer me an excellent training environment. Successful completion of this fellowship proposal will not only reveal the extent to which miRNAs are dysregulated in human models of FXS, but also reveal whether FMRP and miRNAs always act in a unimodal manner. Of equal importance, this project coupled with Dr. Bassell's mentorship will allow me to transition from a molecular cancer biologist to an independent molecular and cellular neurobiologist.

项目摘要：脆性X综合征(FXS)是两种遗传性智力疾病最常见的形式 自闭症的残疾和单基因原因。它是由脆性X信使核糖核蛋白1丢失引起的 (FMR1/FMRP)蛋白。FMRP是一种RNA结合蛋白，通过多种方式调节靶向mRNAs， 例如控制mRNA的本地化、稳定化、编辑和/或翻译。翻译性压制 FMRP在神经元过程中尤其重要，在神经元过程中，蛋白质的合成必须有序地控制 时尚。在没有FMRP的情况下，翻译控制被扰乱，导致树突的过度生产 促进未成熟脊椎FXS神经元表型和过度兴奋性的蛋白质。恰当的翻译 FMRP的调控需要microRNAs(MiRNAs)和RNA诱导的沉默复合体(RISC)。RISC 利用miRNA和靶mRNA之间的碱基匹配在转录后调节基因表达， 这允许特定识别靶向mRNA。已有研究表明，miRNAs在 几个FXS模型；然而，还没有研究公正地描述人类完整的mi RNA场景 FXS型号。FMRP-miRNA介导的基因调控的另一个未解决的方面是，相互作用 总是很合作的。最近的研究强调了FMRP在促进 翻译，而不是压制它。因此，我假设FMRP的丢失改变了miRNA的格局，并且 FMRP不仅协调miRNA介导的抑制，而且在某些情况下拮抗miRNA-RISC 保护成绩单不受不当监管的机制。为了验证我的假设，我将进行实验 针对以下目标：1)测试FMRP的缺失是否会改变全局神经元miRNA的表达模式， MiRNA掺入RISC，miRNAs定位于神经元突起。2.)确定是否 FMRP-microRNA相互作用调节FMRP靶mRNAs的全局和/或局部翻译。要完成 为了实现这些目标，我将需要在诱导多能干细胞培养、神经器官和显微镜方面进行新的培训。 我的赞助人加里·巴塞尔博士在这些方法方面拥有专业知识，埃默里大学的科学界 医学院将为我提供一个很好的培训环境。圆满完成这项奖学金 该提议不仅将揭示在人类FXS模型中miRNAs的失调程度，而且还 揭示FMRP和miRNAs是否总是以单峰方式发挥作用。同样重要的是，这个项目结合了 在巴塞尔博士的指导下，我将从一名分子癌症生物学家转变为一名独立的 分子和细胞神经生物学家。