Abstract 12532: Cellular and Cardiac Microtissue Assays of iPSC-derived Myocytes With the Hypertrophic Cardiomyopathy Mutation in MYH7-Val606Met

• DOI: 10.1161/circ.132.suppl_3.12532
• Publication Date: 2024-04-23T10:56:22Z
• Authors: Calvin C Sheng; John T Hinson; Anant Chopra; Christopher S Chen; Jonathan Seidman; Christine Seidman

Introduction: Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease affecting 1 in 500 people and leading cause of sudden cardiac death young adults. Mutations β-myosin heavy chain ( MYH7 ) account for one-third cases, but underlying pathogenesis remains unclear. In this study, we investigated myocytes derived from CRISPR-Cas9-engineered isogenic induced pluripotent stem cell cardiomyocytes (iPSC-CMs) with a missense mutation Val606Met by single-cell microtissue functional assays. Hypothesis: We hypothesize that iPSC-CMs will recapitulate features HCM single assays, such as changes contractile function hypertrophic signaling. Methods & Results: mutations (VM/+, VM/VM) were introduced targeting an iPSC line using CRISPR-Cas9. Transfected iPSCs isolated FACS to detect green fluorescent protein, clones expanded, mutational events confirmed Sanger sequencing. Mutant iPSCs, like wildtype control differentiated into >90% efficiency. Microtissue studies mutant exhibited increases contractility (WT=2.96±0.23μN, VM/+ = 3.51±0.34μN, VM/VM 4.63±0.51; R 2 0.963). also showed evidence altered signaling spontaneous beating rate (WT < VM/VM; =0.946), size (compared WT, ~20% both VM/+, p=0.04 VM/VM, p=0.038), sarcomere content p=4e-06 p=0.11). These are supported activated expression genes NPPA , NPPB ACTA2 well transcriptional up-regulation TGF-β. Conclusions: Isogenic variant created CRISPR-Cas9 vitro . Our data confirms pathogenic causes increased microtissues myocyte hypertrophy. speculate myocyte-derived TGF-β may contribute phenotype. This approach could be used better understanding genotype-phenotype correlations HCM.