Cardiotoxicity screening methods
Screening compounds by exposing a plurality of cardiomyocytes to a compound, wherein the cardiomyocytes express an optogenetic reporter of membrane potential and an optogenetic reporter of calcium level; receiving light from the optogenetic reporter of membrane potential; creating an AP waveform using the received light; and analyzing the AP waveform to determine the presence or absence of a risk for arrhythmia associated with the compound.
1. A cardiomyocyte expressing:
at least one microbial rhodopsin as an optogenetic reporter of voltage activity, wherein the microbial rhodopsin is one selected from the list consisting of QuasAr1 and QuasAr2;
a light-gated ion channel as an optogenetic actuator of electrical activity; and
a genetically encoded calcium indicator as an optogenetic reporter of calcium level.
2. The cardiomyocyte of claim 1 , wherein the genetically encoded calcium indicator comprises a GCaMP variant.
3. The cardiomyocyte of claim 2 , wherein the genetically encoded calcium indicator is one selected from the list consisting of jRCaMP1a, jRGECO1a and RCaMP2.
4. The cardiomyocyte of claim 3 , wherein the light-gated ion channel comprises a blue-shifted actuator and the genetically encoded calcium indicator comprises a red-shifted calcium indicator.
5. The cardiomyocyte of claim 4 , wherein the light-gated ion channel comprises an algal channelrhodopsin.
6. The cardiomyocyte of claim 5 , wherein the light-gated ion channel comprises a blue-shifted actuator that is one selected from the list consisting of CheRiff, TsChR, and PsChR.
7. The cardiomyocyte of claim 6 , wherein the microbial rhodopsin and the genetically encoded calcium indicator are expressed together as part of a fusion protein.