High Throughput Screening of Pharmaceuticals Targeting Heart Cell Contractile Function

ABSTRACT The overarching goal of this proposal is to produce a desktop instrument that will characterize the physiological state of at least 10,000 cardiac myocytes per day. This represents roughly a 1,000-fold increase in cell throughput compared to conventional technology. Substantial progress was made during Phase I of this project. We developed and have marketed a platform that can routinely measure high temporal resolution sarcomere shortening under environmentally stable conditions at over 1,000 cardiac myocytes per day. The major limitation of the current design developed in Phase I is that cells are recorded sequentially, one at a time, plated on a single dish. In this Phase II proposal we aim to 1) substantially increase cell throughput using rapid, parallel data acquisition and analysis of cells plated in a multi-well plate, 2) allow for analysis of different tissue types, and 3) to automate robotic drug delivery and analyses that result in characterizing the response of myocyte contractility, action potential and calcium regulation. We will achieve a throughput goal of up to ~10,000 cells per day by recording from 3-5 cells simultaneously using video imaging of both contractility and fluorescence, which indicates action potential or calcium regulation. The goal is to characterize the physiological state of up to ~100 cells per well within each well of a 96 well plate in less than 4 hours. Additionally, we aim to extend measurement tools to allow analysis of human induced pluripotent stem cell (hiPSC)- derived cardiac myocytes in the form of monolayer preparations, embryonic bodies, and mechanically loaded microtissues. The proposed Phase II system would be the first commercially available measuring the functional output of these cell and tissue types in real time. This will help advance the field of personalized medicine and facilitate the use of hiPSC-cardiomyocytes in disease modeling and drug testing. Lastly, we propose to fully automate data collection and analyses. Sarcomeres within each cell will be automatically identified and shortening-relaxation dynamics will be automatically characterized for physiological function. Similar automated analyses would be performed for fluorescence, which would reflect action potential or calcium regulation dynamics. These automated analyses will be more objective and more accurate than previously performed and will eliminate potential experimenter bias. Achieving these goals will greatly benefit efforts in: 1) basic research, enhancing our understanding of cardiac function as population characteristics of cells can be described instead of relying on very small samples, 2) safety pharmacology, allowing pre-clinical compounds to be more thoroughly tested before trials, and 3) most significantly, drug development, enabling more compounds to be tested on both adult and hiPSC-cardiomyocytes during discovery.NARRATIVE This project will result in a new instrument useful for rapidly measuring the contractile function and ion regulation in heart muscle cells. The device will be especially useful in screening drugs for effectiveness in treating heart disease.