Table 1 Summary of measurements across experimental groups for Figs. 2, 3 and 4

From: Tracking single hiPSC-derived cardiomyocyte contractile function using CONTRAX an efficient pipeline for traction force measurement

a

Experimental group

 

Spread area (mean ± std (n)) (μm2)

Aspect ratio (mean ± std (n))

p-value (bold = significant)

Linear regression area vs aspect ratio

Substrate stiffness M16lac

10 kPa

769 ± 353 (590)

4.25 ± 1.92 (590)

Spread area: p = 0.0687

Aspect ratio: p < 0.0001

m = 84.11

p = 0.0599

35 kPa

719 ± 314 (282)

2.98 ± 1.81 (282)

Media 10 kPa

M16lac

769 ± 353 (590)

4.25 ± 1.92 (590)

Spread area: p < 0.0001

Aspect ratio: p = 0.0757

m = 84.58

p = 0.1986

M16glu

879 ± 380 (498)

4.08 ± 1.99 (498)

Time course: M16lac 10 kPa

d20

769 ± 353 (590)

4.25 ± 1.92 (590)

Spread area (20 vs. 30; 20 vs. 40; 30 vs. 40) p = (0.209; 0.0018; 0.140) Aspect ratio (20 vs. 30; 20 vs. 40; 30 vs. 40) p = (0.7794; 0.4587; 0.2311)

m = 91.04

p = 0.1044

d30

830 ± 421 (376)

4.37 ± 2.05 (376)

d40

909 ± 460 (220)

4.23 ± 2.22 (220)

b

Experimental group

 

Contractile Force: geometric mean [95% conf. interval] (n) (nN)*

p-value (bold = significant)

Slope of linear regression vs Aspect ratio (mean ± SE)

M16lac

10 kPa

13.88 (12.42–15.52) (590)

p < 0.0001

3.934 ± 0.776

35 kPa

23.34 (19.54–27.93) (282)

10.71 ± 1.698

10 kPa

M16lac

14.16 (12.71–15.78) (590)

p = 0.0315

3.934 ± 0.776

M16glu

17.13 (14.93–19.68) (498)

4.701 ± 1.354

c

Experimental group

 

Power law regression fit p-value, R2

Log-log slopes & SE

p-value (bold = significant)

M16lac

10 kPa

Force: <0.0001, 0.474 (F = 494.0, DFn = 1, DFd = 549) Power: <0.0001, 0.764 (F = 168.7, DFn = 1, DFd = 284)

0.687 ± 0.0309

1.558 ± 0.0365

p = 0.0029 (F = 9.924, DFn = 1, DFd = 833)

35 kPa

Force: <0.0001, 0.373 (F = 1819, DFn = 1, DFd = 560) Power: <0.0001, 0.649 (F = 523.7, DFn = 1, DFd = 283)

0.892 ± 0.069

1.796 ± 0.0785

p = 0.0032 (F = 9.757, DFn = 1, DFd = 843)

10 kPa

M16lac

Force: <0.0001, 0.474 (F = 494.0, DFn = 1, DFd = 549) Power: <0.0001, 0.764 (F = 420.9, DFn = 1, DFd = 497)

0.687 ± 0.0309

1.558 ± 0.0365

p = 0.0317 (F = 4.625, DFn = 1, DFd = 1046)

M16glu

Force: <0.0001, 0.459 (F = 1819, DFn = 1, DFd = 560) Power: <0.0001, 0.698 (F = 1137, DFn = 1, DFd = 492)

0.792 ± 0.0386

1.677 ± 0.0497

p = 0.0512 (F = 3.810, DFn = 1, DFd = 1052)

  1. a Cell morphology measurements: mean values show a statistically significant decrease in aspect ratio on stiffer 35 kPa substrates and larger cell area in, M16glu. The standard deviations show a large variance across each group. Data distribution was tested for normality and lognormality, and comparisons were made accordingly using a two-tailed unpaired t-test with confidence interval of 95% for the effect of stiffness and media, and using ordinary ANOVA test corrected for multiple comparison using the Tukey’s method and reporting multiplicity adjusted p-values using a confidence interval of 95%. b Contractile force measurements: The geometric mean of the contractile force (lognormal distribution) shows stronger force production on 35 kPa substrates and in M16glu medium versus control conditions of 10 kPa substrate stiffness, M16lac culture medium, and experimental day 20 (d20 post differentiation). In the last column, we report the slope of the linear regression and the standard error of estimate for comparison of the linear model. Data distribution was tested for normality and lognormality, and comparisons were made accordingly using two-tailed unpaired t-test with confidence interval of 95% for the effect of stiffness and media. c The slope of log the contraction force and power versus the log of the contractile velocity is higher on 35 kPa and in M16glu medium versus control condition. The log-log regression models were compared using extra sum-of-squares F tests using a 95% confidence interval against the null hypothesis of zero-slopes and against each other.
  2. * m = slope of the linear regression.
  3. *(lognormal distribution).
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