Figure 3.

Differentiation of hPSCs into the cardiac lineage. (A) Confocal immunofluorescence images of cardiac sarcomeric proteins TNNI (green) and α-actinin (red) in human CMs generated from LQT2-hiPSCs^N996I, LQT2-hiPSCs^corr, NKX2.5^eGFP/w hESCs, and NKX2.5^eGFP/w hESCs^N996I. Nuclei are stained in blue. Bottom panels are a magnification of the area framed in the upper images. Top panels, scale bar: 25 μm; bottom panels, scale bar: 10 μm. (B) Transcriptional profile of human CMs generated from mutated and corrected hiPSCs (LQT2-hiPSCs^N996I and LQT2-hiPSCs^corr, respectively) and from wild-type and mutated hESCs (NKX2.5^eGFP/w hESCs and NKX2.5^eGFP/w hESCs^N996I, respectively). Undifferentiated cells from each hPSC line are also shown (Undiff.). Quantitative RT–PCR analysis was performed on the cardiac troponin gene (TNNT2), to show enrichment for the cardiomyocyte population, on the HERG channel gene (KCNH2), and on other key genes encoding for ion channels involved in the generation of the action potential in cardiac cells. All values are normalized to GAPDH and are relative to undifferentiated NKX2.5^eGFP/w hESCs. Raw minimum (min) and raw maximum (max) values were taken as a reference for heatmap representation.