Figure 5.

Functional and transcriptional analysis after laminin-511/521 treatments. (a) Proportions of mononuclear and binuclear cells in PSC-CMs cultured on laminin-511/521 compared to gelatin (n > 100). (b) Representative images of PSC-CMs stained for Cx43 at day 38 of differentiation. Scale bar, 20 μm. (c) Representative traces for PSC-CMs on laminin-511/521 and gelatin responding to oligomycin, FCCP, and rotenone/antimycin A. (d) Statistical analyses of OCRs for (i) Basal respiration, (ii) ATP-linked respiration, (iii) proton leak, and (iv) maximal respiration. Data are presented as means ± SD (n = 3). Dunnett’s test was used to compare PSC-CMs on laminin with ones on gelatin as a control; *P < 0.05, ^§P < 0.01, ^#P < 0.001, ^†P < 0.0001. (e) Representative intracellular calcium transients from PSC-CMs on gelatin and laminin-511/521, stimulated at 1 Hz, at day 38. (f) Mean values of time to peak, peak amplitude, and decay time of Ca²⁺ transients (n > 80). Dunnett’s test; *P < 0.05, ^†P < 0.0001. (g) Representative traces showing sarcomere length during electric-pulse stimulation (1 Hz). (h) Averaged data of sarcomere shortening. Data are presented as means ± SD (n > 40). Dunnett’s test; *P < 0.05, ^§P < 0.01. (i) Averaged gene expression of 8 selected GO terms for biological processes. (j) Compared to gelatin, known genes related to the development of cardiomyocytes were upregulated in PSC-CMs on laminin-511/521 such as cardiac marker genes (Tnnt2 and Actc1), a transcription factor gene for cardiac gene expression (Ankrd23), a calcium handling gene (Casq2), and sarcomere genes (Mybpc2, Mybpc3, Myh7, and Myl2).