Structure of the Thin Filament in Human iPSC-derived Cardiomyocytes and its Response to Heart Disease
Year: 2023
Type: preprint
Abstract: Cardiovascular diseases are a leading cause of death worldwide, but our understanding of the underlying mechanisms is limited, in part because of the complexity of the cellular machinery that controls the heart muscle contraction cycle. Cryogenic electron tomography (cryo-ET) provides a way to visualize diverse cellular machinery while preserving contextual information like subcellular localization and transient complex formation, but this approach has not been widely applied to the study of heart muscle cells (cardiomyocytes). Here, we deploy an optimized cryo-ET platform that enables cellular-structural biology in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Using this platform, we reconstructed sub-nanometer resolution structures of the human cardiac muscle thin filament, a central component of the contractile machinery. Reconstructing the troponin complex, a regulatory component of the thin filament, from within cells, we identified previously unobserved conformations that highlight the structural flexibility of this regulatory complex. We next measured the impact of chemical and genetic perturbations associated with cardiovascular disease on the structure of troponin. In both cases, we found changes in troponin structure that are consistent with known disease phenotypes-highlighting the value of our approach for dissecting complex disease mechanisms in the cellular context.
Language: English
Subfield: Structural Biology
Domain: Life Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, Silicon Valley Community Foundation, National Institutes of Health, National Heart, Lung, and Blood Institute, National Institute of General Medical Sciences, National Institute of Biomedical Imaging and Bioengineering, Division of Electrical, Communications and Cyber Systems, SLAC National Accelerator Laboratory, Common Fund
Awards: Myosin Movement In Vitro - Molecular Characterization, NNCI: nano@stanford, Cryo-electron tomography to determine crosstalk mechanisms of calcium channels in cardiomyocytes, The Stanford-SLAC CryoEM Center, Parallel Characterization of Genetic Variants in Chemotherapy-Induced Cardiotoxicity Using iPSCs, G4089419421, G453897845, G4893461164, G5442025106, G6719595188, G7885819337, G8065195062, G9000097965, Molecular mechanisms underlying force transduction at cellular adhesion complexes, Multi-Disciplinary Training Program in Cardiovascular Imaging at Stanford, Stanford-SLAC CryoET Specimen Preparation Service Center (SCSC), Modeling myosin mechanobiology towards understanding the mechanisms of hypertrophic cardiomyopathy
OpenAlex ID: W4387973409