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.

The ICH E14/S7B 2022 Q&As stipulate that in vitro hERG assessments should be conducted in accordance with Good Laboratory Practice (GLP). We present a GLP compliant study using the conventional manual patch-clamp technique in accordance with the ICH E14/S7B Q&A best practice guidelines to establish in-house IC50 values for ondansetron, moxifloxacin and dofetilide.

Eliana is a two-year-old from Canada with a de novo mutation (V434L) in her KCNC1 gene which encodes for the Kv3.1 channel in central nervous system neurons such as cerebellar neurons and GABAergic interneurons. The mutation manifests as a variety of neurological disorders which can include myoclonic epilepsy and ataxia due to K+ channel mutation, developmental epileptic encephalopathy (DEE), or hypotonia, depending on the specific variant. Although Eliana does not exhibit typical DEE, she suffers from hypotonia, cortical-visual impairment, vertical nystagmus, and global delays.

The endo-lysosomal system is a series of intracellular organelles responsible for recycling and degradation of macromolecules. Endo-lysosomes express several functionally diverse ion channels, crucial for regulating organelle trafficking and intracellular signalling as well as maintaining the acidic luminal pH for optimal enzymatic activity. Dysfunctions within the endo-lysosomal system are associated with multiple disorders including lysosomal storage disorders and neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease. Lysosomal ion channels have therefore gained significant attention as potential targets for novel therapeutics.

Domainex and Metrion Biosciences have formed an alliance to identify new chemical hits against ion-channel targets. Key to this collaboration are Domainex’s experience in hit identification and Metrion Bioscience’s expertise in ion channel screening and pharmacology.