Figure 7.

GCaMP5G-Based Calcium Imaging of CPVT2-hiPSC-CMs

(A) Differentiation of the CPVT2-hiPSCs (left; scale bar, 100 μm) into cardiomyocytes positively stained for sarcomeric α-actinin (middle) and cTnI (right). Scale bars, 20 μm. See also Figure S4.

(B) qPCR analysis of the CPVT2-hiPSC-CMs showing expression of cardiac-specific genes (NKX2.5, MLC-2V, MYH-6, and MYH-7) and downregulation of OCT4 and NANOG. Experiments included three biological replicates measured as two technical replicates.

(C and D) GCaMP5G optical calcium imaging of healthy control (C) and CPVT2 (D) hiPSC-CMs. The CPVT2-cardiomyocytes were highly arrhythmogenic, displaying diastolic local calcium release events (top), double-humped signals (second panel), and sustained arrhythmias (bottom).

(E) An example of new arrhythmias in a CPVT2-hiPSC-CM (bottom) caused by isoproterenol.

Error bars represent SEM.