Fig. 2. Overexpression of 4F for 48 h induces sarcomere disassembly in hiPS-CMs.
(a) The bar graph shows the top GO terms for the significantly downregulated genes from RNA-seq data comparing gene expression between the hiPS-CMs infected with either LacZ or 4F for 48 h (padj<0.05). The GO terms reflect the downregulation of cardiac contractile and sarcomeric genes. (b) Row normalized Z score heatmap shows the contractile and sarcomeric gene expression in a time-dependent manner following 4F expression (n=3 in each sample). Source data 1 lists FPKM values for all RNAseq data and for the heart maps. Source data 2 contains the full list of the GO terms and the genes included in each GO term. (c) Representative traces of impedance recording for contractile function from hiPS-CMs at 24, 48, and 84 h after infection with 4F. The bottom right panel shows the quantification of the contractile force amplitude comparing LacZ- and 4F-treated hiPS-CMs, 24, 48, and 84 h post-infection (n=3 independent experiments each in triplicate, *p<0.05 compared to LacZ treated cells). (d) representative images of sarcomere disassembly during G2/M phase in hiPS-CMs infected with lacZ (top panel), or 4F adenovirus for 48 h (middle (anaphase example) and bottom (cytokinesis example) panels) and stained with antibodies against the sarcomeric protein (troponin-T) (green), G2/M phase marker (PHH3) (red), and nuclear DAPI (blue).