Fig. 4.

Alteration of calcium cycling in LMNA cardiomyopathy.

(A) Line-scan images during field stimulation at 2 Hz of representative isolated cardiomyocytes from 3 months-old wild type (WT) and Lmna^H222P/H222P mice. Below each image, there are represented the fluorescence traces in black for the cytosolic [Ca²⁺]i transient, and in gray for the ca transient inside the nucleus in the WT cell. The same for the Lmna^H222P/H222P in red (cytosolic) and in dark red (nuclear).

(B) Graph showing values of peak calcium transients (F/F₀), peak nuclear calcium transients (F/F₀), time to peak and decay time constant of steady-state Ca²⁺ transients from isolated cardiomyocytes from 3 months-old wild type (WT) and Lmna^H222P/H222P mice. The number of cardiomyocytes is indicated. (t-test).

(C) Line-scan images of caffeine-evoked intracellular Ca²⁺ transients after field stimulation at 2 Hz of representative isolated cardiomyocytes from 3 months-old wild type (WT) and Lmna^H222P/H222P mice obtained by the application of 10 mmol/L caffeine.

(D) Graph showing values of maximum amplitude of caffeine-induced SR Ca²⁺ release, indicative of SR Ca²⁺ load (F/F₀) and decay time constant of caffeine-induced SR Ca²⁺ release, indicative of cytosolic Ca²⁺ extrusion Ca²⁺ from isolated cardiomyocytes from 3 months-old wild type (WT) and Lmna^H222P/H222P mice. The number of cardiomyocytes is indicated. (t-test).