Biophysical Society Thematic Meeting - June 28-July 1, 2015

New Biological Frontiers Illuminated by Molecular Sensors and Actuators

Poster Abstracts

5-POS

Board 5

Genetically Encoded Tools to Manipulate and Observe Cellular Dynamics in Cardiac Disease Modelling and Drug Screening Yu-Fen Chang , Frances Book, Mark J. Davies, Matthew J. Daniels. University of Oxford, Oxford, United Kingdom. Optogenetic technology allows us to control depolarization of electrically excitable cells using ion-channels that open in response to light. Genetically Encoded Calcium Indicators (GECIs) can be utilized to visualize cellular response upon opto-stimulation in real time. Previously, we have successfully demonstrated the use of channelrhodopsin2 (ChR2), a light sensitive cation channel, with a spectrally compatible red shifted calcium indicator (R-GECO) in a transient expressing neuronal model. Here, we presented a viral delivery system for the two component parts (an improved ChR2 and R-GECO) required to target relevant cardiac substrates such as adult guinea pig cardiomyocytes human-embryonic-stem-cell derived cardiomyocytes (hES-CM), and patient derived iPS cardiomyocyte derivatives allowing light stimulation with simultaneous Ca++ imaging. To prove the concept of contactless drug screening in excitable cells, known small molecules were tested on hES-CMs in multi-well plates. Increased Ca++ influx was observed in hES-CMs upon blue light stimulation after treatment of BayK8644, the L-Type Ca++ channel agonist. On the other hand, cytosolic calcium fell upon light activation after treating with BAPTA, a Ca++ chelator. The contactless nature of this technology enables high-throughput drug screening to be targeted to rapid and reversible phenomena like Ca++ handling, providing a new platform for cardiac disease modelling.

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