Project 1 - Genes to Function: Causal Genes and their Roles in Cardiomyocyte and Atrial Physiology

项目 1 - 发挥功能的基因：因果基因及其在心肌细胞和心房生理学中的作用

• 批准号: 10410648
• 负责人: Jonathan D Smith
• 金额: $ 50.72万
• 依托单位: CLEVELAND CLINIC LERNER COM-CWRU
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10410648
• 关键词: 10q22; Actins; Action Potentials; Address; Adult; Affect; Age; Atrial Fibrillation; Binding; Breeding; Calcium; Cardiac Myocytes; Cell Nucleus; Cessation of life; Chromosomes; Clinical; Collaborations; Complex; Cytoplasm; Cytoskeleton; Data; Development; Doctor of Philosophy; Dominant-Negative Mutation; Electrophysiology (science); Engineering; FDA approved; Gene Expression; Gene Expression Regulation; Genes; Goals; Heart Atrium; Heart failure; Heritability; Human; Human Genome; Incidence; Individual; Ion Transport; Knockout Mice; Knowledge; Left; Left atrial structure; Linkage Disequilibrium; Metabolism; Molecular; Morphology; Nuclear; Nuclear Envelope; Obesity; Pathway interactions; Pharmaceutical Preparations; Physiology; Predisposition; Program Description; Protein Isoforms; Proteins; Quantitative Trait Loci; Research; Risk; Role; Sarcoplasmic Reticulum; Single Nucleotide Polymorphism; Sinus; Stroke; Structure; Tamoxifen; Testing; Therapeutic; Tissues; Transcript; Transcription Initiation Site; Transgenic Mice; Variant; Ventricular; Work; analysis pipeline; auricular appendage; biracial; causal variant; cohort; design; drug candidate; functional genomics; gain of function; genetic association; genetic variant; genome wide association study; genomic locus; heart function; human stem cells; improved; in vivo; insight; knock-down; mouse model; novel; novel therapeutic intervention; overexpression; programs; response; risk variant; stem cell differentiation; therapeutic evaluation; transcriptome; transcriptome sequencing; transcriptomics

Project 1 Summary: Atrial fibrillation (AF) increases risk of heart failure, stroke and death, and its incidence increases with age and obesity. Human genome wide association studies (GWAS) have identified ~140 genetic loci associated with AF susceptibility, but it still takes dedicated functional and molecular studies to identify the causal gene, the causal genetic variant, and the mechanisms for AF association. We are very excited to pursue two AF risk loci on chromosomes 10q22 (SYNPO2L and MYOZ1 genes) and 14q23 (SYNE2 gene). We are poised to discover the mechanism by which these two loci increase AF susceptibility, and identify gene centric repurposable drugs, which may be targeted to individuals carrying these risk alleles. We chose both loci for study as the GWAS single nucleotide polymorphism (SNP) was associated with expression of a nearby gene; thus, the causal SNP, which can be in linkage disequilibrium with the GWAS SNP, may work by regulating gene expression. These associations with gene expression were for specific transcript isoforms of SYNPO2L and SYNE2 due to alternative transcription start sites. In Aim 1, we will study the complex AF locus on chromosome 10q22, where the AF risk allele is associated with decreased expression of MYOZ1, but increased expression of the shorter isoforms of SYNPO2L. Both of these genes encode Z disk proteins, which may directly affect contractility and secondarily alter Ca2+ handling that may impact cellular electrophysiology. We will study how changes in the expression of MYOZ1 and the SYPO2L isoforms alter contractility and electrophysiology in human stem cells differentiated into atrial-like cardiomyocytes (a-iCMs) and engineered heat tissue (EHT). In Aim 2, we will build on our preliminary human iCM studies, where we found that the chromosome 14q23 AF risk allele is associated with less expression of a SYNE2 short isoform. SYNE2 encodes a protein that connects the nucleus to the cytoplasm, but the short isoform does not bind to the cytoskeleton, and acts as a dominant negative to disrupt the nuclear-cytoplasm connection. RNAseq from SYNE2 short isoform overexpression in a-iCMs showed a large effect on Ca2+ handling proteins. We looked at Ca2+ handling and action potentials; knockdown of all SYNE2 isoforms led to increased early afterdepolarizations, which was rescued by over expression of the short isoform. Short isoform over expression also decreased peak Ca2+ content. We discovered that the SYNE2 short isoform also binds to the sarcoplasmic reticulum. In this aim we are poised to determine if over expression of the SYNE2 short isoform can protect against AF in a mouse model of spontaneous AF. In collaboration with SC3 and P3, Aim 3 will use the RNAseq data from Aims 1 and 2 to identify “gene effect modules”, for which we will identify module altering repurposalbe drugs, which will be tested for beneficial effects in a-iCMs and EHTs. Successful completion of our aims will make significant contributions to AF functional genomics and therapeutics.

项目1摘要： 心房颤动（AF）增加了心力衰竭，中风和死亡的风险，其发病率随着年龄的增长而增加 肥胖。人类基因组广泛的关联研究（GWAS）已经确定了〜140遗传局部与 AF敏感性，但仍需要专门的功能和分子研究来识别因果基因，即 因果遗传变异和AF关联的机制。我们很高兴追求两个AF风险基因座 在染色体10q22（synpo2l和Myoz1基因）和14q23（SYNE2基因）上。我们被毒死 这两个语言环境提高AF敏感性并识别为基因以基因为中心的机制 药物可能针对携带这些风险等位基因的个体。我们选择两个当地人作为研究 GWAS单核苷酸多态性（SNP）与附近基因的表达有关。因此， 可以通过调节基因来起作用的因果SNP，可以与GWAS SNP进行连锁二极管 表达。这些与基因表达的关联是用于synpo2l的特定转录本和 SYNE2由于替代转录启动位点。在AIM 1中，我们将研究复杂的AF基因座 染色体10q22，其中AF风险等位基因与Myoz1的表达降低相关，但 synpo2l的短同工型表达增加。这两个基因编码Z磁盘蛋白， 可能会直接影响收缩性和次级Alter Ca2+处理，这可能会影响细胞电生理学。 我们将研究Myoz1和Sypo2L同工型的表达变化如何改变收缩性和 人类干细胞中的电生理学分化为心房样心肌细胞（A-ICMS）并进行了设计 热组织（EHT）。在AIM 2中，我们将基于我们的初步人类ICM研究，在那里我们发现 14q23 AF风险等位基因染色体与SYNE2短同工型的表达相关。 Syne2 编码将细胞核连接到细胞质的蛋白质，但短同工型不结合 细胞骨架，并充当破坏核胞质连接的主要阴性。 RNASEQ来自 A-ICMS中的SYNE2短亚型过表达对Ca2+处理蛋白具有很大的影响。我们看了看 CA2+处理和动作电位；所有SYNE2同工型的敲低导致早期增加 源后极性，这是通过短同工型的过度表达作出反应的。短同工型超过表达 也降低了峰值Ca2+含量。我们发现SYNE2短同工型也与 肌质网。在此目标中，我们被毒死以确定SYNE2短同工型的表达是否过度 可以在赞助AF的鼠标模型中预防AF。与SC3和P3合作，AIM 3将使用 AIM 1和2的RNASEQ数据以识别“基因效应模块”，为此我们将确定更改模块 Repurposalbe药物将在A-ICMS和EHT中测试有益作用。成功完成 我们的目标将为AF功能基因组学和治疗做出重大贡献。