Electrophysiological characterisation of iPSC-derived human β-like cells and an SLC30A8 disease model.

iPSC-derived human β-like cells (BLC) hold promise for both therapy and disease modelling, but their generation remains challenging and their functional analyses beyond transcriptomic and morphological assessments remain limited. Here, we validate an approach using multicellular and single cell electrophysiological tools to evaluate function of BLCs from pioneer protocols that can be easily adapted to more differentiated BLCs. The Multi-Electrode Arrays (MEAs) measuring the extracellular electrical activity revealed that BLCs are electrically coupled, produce slow potential (SP) signals like primary β-cells that are closely linked to insulin secretion. We also used high-resolution single-cell patch-clamp measurements to capture the exocytotic properties, and characterise voltage-gated sodium and calcium currents and found that they were comparable to those in primary β and EndoC-βH1 cells. The KATP channel conductance is greater than in human primary β-cells which may account for the limited glucose responsiveness observed with MEA. We used MEAs to study the impact of the type 2 diabetes protective SLC30A8 allele (p.Lys34Serfs*50) and found that BLCs with this allele have stronger electrical coupling activity. Our data suggest that BLCs can be used to evaluate the functional impact of genetic variants on β-cell function and coupling.