A non-invasive platform for functional characterization of stem-cell-derived cardiomyocytes with applications in cardiotoxicity testing.
Bottom Line: We present a non-invasive method to characterize the function of pluripotent stem-cell-derived cardiomyocytes based on video microscopy and image analysis.The platform, called Pulse, generates automated measurements of beating frequency, beat duration, amplitude, and beat-to-beat variation based on motion analysis of phase-contrast images captured at a fast frame rate.Using Pulse, we demonstrate recapitulation of drug effects in stem-cell-derived cardiomyocytes without the use of exogenous labels and show that our platform can be used for high-throughput cardiotoxicity drug screening and studying physiologically relevant phenotypes.
Affiliation: Cellogy, Inc., Palo Alto, CA 94301, USA. Electronic address: email@example.com.Show MeSH
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Mentions: The hERG potassium channel is involved in regulating cardiac repolarization. In addition to arrhythmia, drugs that block its function have been associated with long QT syndrome. On an electrophysiological level, this is reflected by increased action potential duration. We reasoned that this should correlate with a change in the duration of physical contraction as measured by Pulse. We tested the effect of various concentrations of hERG inhibitors including cisapride, E-4031, and sotalol and observed an increase in beat duration, as shown in Figures 5B, 5C, and 5F, respectively. This effect was dose dependent, with the exception of cisapride at 200 nM, the respective maximal dose that was used. This may be partially due to cytotoxicity, as we observed beating cessation in several of the 200 nM cisapride-treated samples. Arrhythmias were observed at elevated doses for E-4031 and cisapride, as shown in the traces in Figures 5C and 5B. Notably, this phenomenon was visible in many, but not all, of the samples treated within effected doses, suggesting that the arrhythmia caused by these drugs may be intermittent. We also note that some of the arrhythmias included shorter “twitch”-like beats, which may have impacted the duration measurements. Additional examples are shown in Figure 6, including 96 beating signals estimated by Pulse and successful detection of arrhythmic beats due to addition of cisapride and E-4031.
Affiliation: Cellogy, Inc., Palo Alto, CA 94301, USA. Electronic address: firstname.lastname@example.org.