Automated Patch-Clamp Methods for the hERG Cardiac Potassium Channel

Area of Science:

• Cardiovascular Pharmacology
• Ion Channel Physiology
• Drug Discovery

Background:

• The human Ether-a-go-go Related Gene (hERG) potassium channel is vital for cardiac action potential repolarization.
• hERG dysfunction is implicated in Long QT Syndrome and Torsades de Pointes (TdP) arrhythmias.
• Assessing hERG inhibitory activity is critical for drug safety and development.

Purpose of the Study:

• To describe optimized bench procedures for preparing hERG-expressing cells for automated patch-clamp.
• To enhance the sensitivity of hERG screening assays.
• To address limitations in detecting micro-precipitation of poorly soluble compounds in high-throughput screening.

Main Methods:

• Culture and preparation of Chinese Hamster Ovary (CHO) cells expressing hERG.
• Recording of hERG channel activity using an automated patch-clamp workstation.
• Evaluation of assay sensitivity with and without surfactant in the extracellular medium.

Main Results:

• Established reliable bench procedures for hERG-expressing cell preparation.
• Demonstrated improved assay sensitivity by adding a surfactant to the extracellular medium.
• Provided a method to enhance the reliability of hERG channel drug screening.

Conclusions:

• Optimized procedures facilitate robust hERG channel screening in drug discovery.
• Surfactant addition enhances assay sensitivity, aiding in the prioritization of drug candidates.
• The described methods improve the efficiency and accuracy of hERG safety pharmacology assessments.