Fig. 8.

K219T-LMNA overexpression in RUES2-CMs reproduces phenotypes of K219T-CMs. a Lentiviral vector expressing the C-terminal GFP-tagged K219T-Lamin A/C used for lentiviral particle production. b Analysis of sodium current (I_Na) densities in CMs differentiated from the human embryonic stem cell line RUES2 and transduced with lentiviral particles expressing K219T-LaminA/C-GFP. Left column: examples of I_Na traces recorded in GFP^neg (top) and GFP^pos CMs (bottom) (Scale bar, 2 ms, 50 pA/pF). Right panel: I-V curves constructed from average peak sodium current density as a function of voltage command measured in GFP^neg and GFP^pos CMs. (GFP^neg: n = 14; GFP^pos: n = 21), showing significant Na⁺ current reductions in GFP^pos cells. c I_Na density, measured at −30 mV, in GFP^pos (115.20 ± 43.35 pA/pF) vs. GFP^neg (164.02 ± 43.18 pA/pF) CMs, expressed as a percentage. d Voltage dependences: steady state activation (GFP^neg: n = 14; GFP^pos: n = 21)/inactivation (GFP^neg: n = 11; GFP^pos: n = 17) curves. e RT-qPCR comparing SCN5A expression in GFP^neg and GFP^pos CMs isolated through FACS sorting. Data are represented relative to GFP^neg samples and normalized to expression of HGPRT and 18S housekeeping genes. Top: gating strategy and cell populations selected for the sorting are shown (sequential sorting strategy is provided in the Supplementary Fig. 15). All values are reported as mean ± SD. *p < 0.05; **p < 0.005 (unpaired t-test)