Fluorescence-lifetime optical electrophysiology in contracting cardiomyocytes

• 成果类型: Article
• 署名作者: Millar, Euan; Huethorst, Eline; Zickus, Vytautas; Astrauskaite, Giedre; Zhao, Jiuxuan; Taylor, Gregor G.; Bruschini, Claudio; Charbon, Edoardo; Smith, Godfrey L.; Mullenbroich, Caroline; Faccio, Daniele
• 署名单位: University of Glasgow; University of Glasgow; Center for Physical Sciences & Technology - Lithuania; Swiss Federal Institutes of Technology Domain; Ecole Polytechnique Federale de Lausanne
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.2533881123
• 发表日期: 2026-06-09
• 页码: e2533881123
• 关键词: fluorescence lifetime; electrophysiology; voltage imaging; calcium imaging; single-photon avalanche diode; CELL-DERIVED CARDIOMYOCYTES; pluripotent stem-cells; calcium; currents; voltage; patient; inward

摘要

Precise monitoring of cardiac electrophysiology in vitro is crucial to understanding heart function and cardiac disease. However, high-throughput, contact-free methods for directly measuring excitation-contraction coupling remain limited. Here, we introduce a paradigm for quantitative electrophysiological imaging that combines fluorescence lifetime and intensity information to capture dynamic cardiac signals with high fidelity. We show that lifetime measurements are intrinsically decoupled from motion artifacts and provide calibrated calcium concentration and membrane potential estimates across wide fields of view. Using a gated single-photon avalanche diode camera, we acquire fluorescence lifetime images at up to 200 frames per second with sufficient signal-to-noise ratio such that each frame contains meaningful lifetime information without temporal averaging. This approach yields spatially resolved maps of voltage and calcium values across contracting cardiomyocyte monolayers, revealing heterogeneous cell behaviors within individual assays and uncovering previously unreported dynamics during late-phase repolarization for real-time analysis of excitation-contraction coupling.