Action Potential Waveform Analysis in Human IPSC-Cardiomyocytes Enables Mechanistic Assessment of Multichannel Cardiac Effects

Cardiac toxicity remains the leading cause of new drug safety side-effects. Current preclinical cardiac safety assays rely on in vitro cell-based ion channel assays and ex vivo and in vivo animal models⁽¹⁾. These assays provide an indication of acute risk but they do not always predict the effect of chronic compound exposure, as recently seen with oncology drugs. Therefore, new assays are required to characterise chronic structural and functional effects in human cells earlier in drug discovery. Impedance-based technology can provide more accurate chronic cardiotoxicity measurements in an efficient manner using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs).

Automated patch clamp enables robust NaV1.9 screening, accelerating discovery of selective sodium channel modulators for pain research.

Automated patch clamp enables robust NaV1.9 screening, accelerating discovery of selective sodium channel modulators for pain research.

The cardiac late Na+ current (late INa) generates persistent inward currents throughout the plateau phase of the ventricular action potential and is an important determinant of repolarisation rate, EADs and arrythmia risk¹. As inhibition of late INa can offset drug effects on hERG and other repolarising K⁺conductances, it is one of the key cardiac channels in the Comprehensive in vitro Pro-arrythmia Assay (CiPA) panel being developed by the FDA to improve human clinical arrythmia risk assessment²̛ ³.

Cardiac toxicity remains the leading cause of new drug safety side-effects. Current preclinical cardiac safety assays rely on in vitro cell-based ion channel assays and ex vivo and in vivo animal models⁽¹⁾. These assays provide an indication of acute risk but they do not always predict the effect of chronic compound exposure, as recently seen with oncology drugs. Therefore, new assays are required to characterise chronic structural and functional effects in human cells earlier in drug discovery. Impedance-based technology can provide more accurate chronic cardiotoxicity measurements in an efficient manner using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs).

Robust high-throughput automated electrophysiology assay using a monoclonal CHO-hNav1.9 cellular reagent suitable for fully supporting a Nav1.9 discovery program.

To overcome seal enhancer limitations, Sophion and Metrion collaborated to determine whether other insoluble salts can act as seal enhancers and how these solution pairs affect the biophysical properties and pharmacology of the investigated ion channels.

A stable cell line expressing KV3.1 V434L variant was developed and characterised, confirming published data describing V434L as a gain-of-function mutation.

The development and validation of electrophysiological assays to study TRPML1 is important to understand the function and pharmacology of the channel. We used a TRPML1 variant that lacks the endo-lysosomal retention sequences (TRPML1-4A), enabling the channel to express at the plasma membrane3. As such channel behaviour can be characterised by means of whole-cell patch-clamp and fluorescence-based techniques.