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Genome-Engineered Stem Cell Models to Determine Disease Mechanisms in MYBPC3 Hypertrophic Cardiomyopathy

基因组工程干细胞模型确定 MYBPC3 肥厚性心肌病的疾病机制

基本信息

批准号：
9321380
负责人：
ADAM S HELMS
金额：
$ 16.33万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-08-01 至 2021-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9321380
关键词：
Acute Address Affect Alleles Arrhythmia Backcrossings Biological Models CRISPR/Cas technology Calcineurin Calcium Calcium Signaling Cardiac Cardiac Myocytes Cardiac Myosins Cell Culture Techniques Cell Line Cell model Cells Chronic Clinical Data Development Development Plans Disease Dominant-Negative Mutation Electrophysiology (science)Etiology Functional disorder Future Genes Genetic Genome Genome engineering Genotype Goals Heart Heart Abnormalities Heart Diseases Heart failure Human Hypertrophic Cardiomyopathy Hypertrophy Impairment Induced Mutation Inherited Knock-in Knock-in Mouse Knock-out Knockout Mice Knowledge Lead Link Measures Modeling Mutation Myocardium Myopathy Organ Pathogenesis Pathway interactions Patients Phenotype Phosphotransferases Population Predisposition Production Protein Truncation Proteins Research Personnel Role Sarcomeres Signal Pathway Signal Transduction Stem cells Stimulus Structure Sudden Death System Techniques Testing Therapeutic Tissue Sample Training Transcript Up-Regulation Work calmodulin-dependent protein kinase II career career development citrate carrier disorder control heart rhythm human disease human stem cells in vivo induced pluripotent stem cell inhibitor/antagonist loss of function mouse model multidisciplinary mutant myosin-binding protein C premature skills therapeutic development transcriptome sequencing

项目摘要

ABSTRACT Hypertrophic cardiomyopathy (HCM) is the most common Mendelian inherited cardiac disease and can be complicated by heart failure, arrhythmias, and sudden death. Over 60% of genetically-defined HCM is due to mutations in MYBPC3. Most MYBPC3 mutations cause premature protein truncations, but the specific mechanisms by which these mutations lead to hypertrophy and arrhythmias is elusive. These mutations may lead to loss of function (haploinsufficiency) but may also exert dominant negative effects from truncated MYBPC3 protein. My previous work has demonstrated an increase in MYBPC3 at the transcript level and no difference in protein abundance, countering the loss of function hypothesis. I have further shown in preliminary data that truncated MYBPC3 proteins demonstrate a capacity for dominant negative effects since they are able to incorporate in the cardiac sarcomere but mislocalize and negatively influence contractility. I hypothesize that truncating mutations in MYBPC3 exert genotype-specific dominant negative effects that impair sarcomere organization, predispose to arrhythmia, and activate hypertrophic signalling. The hypothesis will be explored with three specific aims, which leverage both human induced pluripotent stem cells derived cardiomyocytes (hiPSC-CMs) to investigate early consequences of MYBPC3 mutations, and mouse models to investigate late consequences of MYBPC3 mutations. The first aim utilizes hiPSC lines that have been genome-engineered using the CRISPR-Cas9 system to create lines that are genetically identical except for an allelic spectrum of three specific MYBPC3 mutations. HiPSC-CM immaturity is addressed using modified cell culture substrates and micropatterning techniques. These hiPSC-CMs will be compared for sarcomere organization, contractility, calcium handling, and arrhythmia susceptibility. The second aim compares a heterozygous MYBPC3 knock-out mouse model with a heterozygous MYBPC3 knock-in (truncating mutation) mouse model, which are direct corollaries for the hiPSC-CM models in the first aim, and will be compared at 6 months for analogous in vivo phenotypes that reflect chronic adverse remodeling. The third aim explores the hypothesis that the calcineurin- CaMKII signaling pathway is critical in the pathogenesis of hypertrophy and arrhythmia susceptibility due to truncating mutations in MYBPC3, as supported by my preliminary data for this pathway in human HCM. The proposal will provide convincing evidence for the role of truncated MYBPC3 dominant negative effects as a mechanistic upstream cause of sarcomere dysfunction, arrhyhthmias, and calcium mishandling in HCM. Furthermore, the findings will have imminent clinical impact since truncating MYBPC3 mutations are the most common genetic cause of HCM, and therefore results of this study have high potential for influencing future genotype-specific therapeutic development. The proposed project and career development plan will also be an excellent training vehicle to achieve my long-term career goal of becoming an independent investigator who will lead a multidisciplinary team to better understand and treat inherited heart disease.

摘要