Figure 2.

Recovered hiPSC-CMs Show Altered Contractility and Ca²⁺ Kinetics in a Line-Dependent Manner

(A and B) Recovered hiPSC-CMs from five lines showed reduced contraction velocity and contraction deformation distance (line 1, n = 20 and 35; line 2, n = 15 and 30; line 3, n = 30 and 30; line 4, n = 50 and 50; line 5, n = 50 and 50 independent measurements in fresh and recovered groups, respectively). Data were collected from three independent differentiations for each line and the assay was repeated three times.

(C) Representative Ca²⁺ transients of line 1 fresh (black) and recovered hiPSC-CMs (blue).

(D and E) Ca²⁺ transient amplitude and half-decay time of Ca²⁺ transients were altered in recovered hiPSC-CMs in a line-dependent manner (line 1, n = 42 and 48; line 2, n = 75 and 82; line 3, n = 55 and 52; line 4, n = 44 and 51; line 5, n = 48 and 58 cells in fresh and recovered groups, respectively). Data were collected from three to five independent coverslip preparations from three independent differentiations for each line.

(F) Immunostaining of line 1 fresh and recovered hiPSC-CMs showed the expression of cTNT (red), α-ACTININ (green), and nuclear stain DAPI (blue). Scale bars represent 30 μm.

(G) Comparable sarcomere length between fresh and recovered groups across cell lines (n = 36 per group from six randomly selected regions).

All data represented as mean ± SEM, ^∗∗p < 0.01, ^∗∗∗p < 0.001, and ^∗∗∗∗p < 0.0001 compared with their respective fresh samples.