Figure 5
Immunofluorescence analysis. Subcellular localisation of α-actinin (green), NaV1.5 (red) and nuclei (blue) in a whole mount immunofluorescent confocal section of left ventricular tissue (LV, two examples, A) and human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) in engineered heart tissue (EHT, two examples, B) and monolayer (ML, C). In contrast to ML, EHT showed a parallel orientation of CM, a more rod-shaped morphology, sarcomere alignment and NaV1.5 enhancement at cell-cell contact (arrow). In some parts of the EHT, NaV1.5 was co-localised with α-actinin at Z-disks (see arrowheads in inset with 2.5 fold magnification), comparable to LV. Scale bar for all images is 10 µm. Black rectangles were placed aside confocal images in A for symmetrical appearance.
