Fig. 5: NAA10-mutant iPSC-CMs have severe structural and contractile defects.
From: Dysregulation of N-terminal acetylation causes cardiac arrhythmia and cardiomyopathy
a Depiction of micro-contact printing with polydimethylsiloxane (PDMS) stamps of fibronectin for spatially restricted patterning of iPSC-CMs. Rectangle patterns have a length-to-width ratio of 7:1 (scale bar: 100 μm). b Confocal micrographs of WT-, pNAA10R4S/Y-, or eNAA10R4S/Y-iPSC-CMs, stained for sarcomeric alpha-actinin (SAA) as either unpatterned (left panels, scale bar: 20 μm) or patterned on micro-contact printed substrates (right panels, scale bar: 10 μm). c A customized Matlab program calculated sarcomeric packing density (SPD) from single micro-patterned iPSC-CMs. SPD reflects sarcomere expression and alignment in a certain area. Therefore, lower SPD values correspond to a more disordered sarcomeric structure. SPD was quantified as 0.44 ± 0.01 for WT, 0.37 ± 0.01 for pNAA10R4S/Y (p < 0.0001), and 0.30 ± 0.01 for eNAA10R4S/Y (p < 0.0001) (n = 153, 66, and 43, independent experiments; n = 3, 3, and 3, independent differentiation experiments; p = <0.0001; Kruskal-Wallis test). d Sarcomere length was measured in single micro-patterned iPSC-CMs and quantified as 1.65 ± 0.01 μm for WT, 1.83 ± 0.03 μm for pNAA10R4S/Y (p < 0.0001), and 1.83 ± 0.03 μm for eNAA10R4S/Y (p < 0.0001) (n = 152, 56, and 36, independent experiments; n = 3, 3, and 3, independent differentiation experiments; p < 0.0001; Kruskal-Wallis test). e Brightfield images of engineered heart tissues (EHTs) created from isogenic control (WT) and eNAA10R4S/Y-iPSC-CMs on PDMS “pillars” after transduction with ChR2-GFP adenovirus for optical pacing (scale bar: 1 mm). f Representative traces of developed contractile force of EHTs calculated from video data of PDMS pillar displacement in response to optical pacing with 488 nm light at 1 Hz. g Quantification of contractile force calculated over 10 beats (WT = 0.46 ± 0.04 mN vs eNAA10R4S/Y = 0.019 ± 0.03 mN; n = 17, and 15, independent experiments; n = 3, and 3, independent differentiation experiments; p < 0.0001; two-tailed unpaired t-test). Data are presented as mean ± SEM. The number of cells or tissues (n) is annotated on each graph. ****p < 0.0001. Source data are provided as a Source Data file.
