High-throughput screening of induced pluripotent stem cell-derived motor neurons on Qube and QPatch
Human induced pluripotent stem cells (hiPSCs) can be differentiated into many cell types, including neurons and cardiomyocytes, and therefore constitute a novel way to model human diseases for drug testing in vitro1. Ion channels represent attractive therapeutic targets in the nervous and cardiovascular systems2 rendering electrophysiological studies of hiPSCs interesting for their usage in drug discovery. However, such studies have traditionally been limited by the labour-intensive and low throughput nature of patch clamp electrophysiology2.
Here we present the electrophysiological characterization of hiPSC-derived motor neurons using our automated patch clamp (APC) platforms, Qube 384 and QPatch. Our results include a measure of channel expression versus time in culture, the pharmacological dissection of endogenous ion channels (e.g. voltage-gated Na+ (NaV) and voltage-gated K+ (KV) channels), identification of ligand-gated receptors and recordings of action potentials using current clamp. The major challenge when investigating neurons using APC platforms is the requirement to dissociate the cells from their neuronal network while maintaining cell viability and membrane integrity3. By optimization of the harvest- and whole-cell protocols we have overcome this obstacle resulting in success rates of up to 60% using our 384-well APC system. Utilizing the high throughput nature of our system we tested in parallel two disease models, using hiPSC neurons derived from Spinal Muscular Atrophy (SMA) or Amyotrophic Lateral Sclerosis (ALS) patients, together with control cells from healthy subjects and isogenic control cells. The results show a general overactivity of Na+ channels in both cell lines, which could be rescued by a point mutation in the superoxide dismutase (SOD1) gene in the isogenic ALS cell line.
Our results demonstrate the feasibility of conducting electrophysiological characterization and screening of hiPSC-derived neurons on APC platforms like Qube 384 and QPatch, thus paving the way for high throughput ion channel-targeted screening of drugs for neurological disorders.