Anion channelrhodopsins for inhibitory cardiac optogenetics.

Elena G Govorunova,Shane R Cunha,Oleg A Sineshchekov,John L Spudich

doi:10.1038/srep33530

Elena G Govorunova, Shane R Cunha + Show 2 more

Open Access

https://doi.org/10.1038/srep33530

Copy DOI

Abstract

Optical control of the heart muscle is a promising strategy for cardiology because it is more specific than traditional electrical stimulation, and allows a higher temporal resolution than pharmacological interventions. Anion channelrhodopsins (ACRs) from cryptophyte algae expressed in cultured neonatal rat ventricular cardiomyocytes produced inhibitory currents at less than one-thousandth of the light intensity required by previously available optogenetic tools, such as the proton pump archaerhodopsin-3 (Arch). Because of their greater photocurrents, ACRs permitted complete inhibition of cardiomyocyte electrical activity under conditions in which Arch was inefficient. Most importantly, ACR expression allowed precisely controlled shortening of the action potential duration by switching on the light during its repolarization phase, which was not possible with previously used optogenetic tools. Optical shortening of cardiac action potentials may benefit pathophysiology research and the development of optogenetic treatments for cardiac disorders such as the long QT syndrome.

Highlights

Optical control of the heart muscle is a promising strategy for cardiology because it is more specific than traditional electrical stimulation, and allows a higher temporal resolution than pharmacological interventions
Anion channelrhodopsins (ACRs) from cryptophyte algae expressed in cultured neonatal rat ventricular cardiomyocytes produced inhibitory currents at less than one-thousandth of the light intensity required by previously available optogenetic tools, such as the proton pump archaerhodopsin-3 (Arch)
We expressed the transmembrane domains of GtACR1, GtACR2 and Arch fused to C-terminal enhanced yellow fluorescence protein (EYFP) under the mouse ubiquitin C promoter in cultured neonatal rat ventricular cardiomyocytes (NRVMs) using lentiviral delivery

Summary

Introduction

Optical control of the heart muscle is a promising strategy for cardiology because it is more specific than traditional electrical stimulation, and allows a higher temporal resolution than pharmacological interventions. Anion channelrhodopsins (ACRs) from cryptophyte algae expressed in cultured neonatal rat ventricular cardiomyocytes produced inhibitory currents at less than one-thousandth of the light intensity required by previously available optogenetic tools, such as the proton pump archaerhodopsin-3 (Arch). Because of their greater photocurrents, ACRs permitted complete inhibition of cardiomyocyte electrical activity under conditions in which Arch was inefficient. By threshold-based closed-loop optogenetics in cardiomyocytes expressing GtACRs we could accelerate repolarization and precisely terminate action potentials at any time during their repolarization phase, which, to the best of our knowledge, has not been previously demonstrated

Methods

Results

Conclusion