Figure 3.

Transiently increased occurrence of longitudinal elements in the TAT system is accompanied by a persistent decrease in JPH2 post-MI and dissociation of Cav-3 into the cytosol. The occurrence of longitudinal elements of the TAT system transiently rises while JPH2 levels decrease and remain decreased from the earliest time point post-MI and Cav-3 levels increase and dissociate from the membrane 16-week post-MI. (A) Top panels: representative 40 × 10 µm frames of the confocal images of cardiomyocytes at different time points (Scale bar equals 2 μm); Bottom panels: axial elements extracted mathematically from frames above as explained in ‘Methods’ section; (B) Number of longitudinal tubules; *P < 0.05 as calculated with mixed ANOVA followed by Wald χ²-test. Sample number N/n = 4/20 each; (C) Representative immunoblots for JPH2 and (D) of Cav-3 as well as the house keeping gene products GAPDH and CSQ, each sample was analysed in triplicates from 3 different animals (control = age matched animals); (E) Representative immunoblots showing dissociation of Cav-3 protein from membrane to cytosol at 4- and 16-week post-MI. SERCA2a was used as membrane fraction marker and GAPDH as cytosolic fraction marker. Ponceau staining was performed as overall loading control. (F) and (G) Density of respective JPH2 bands in (C) normalized to corresponding GAPDH bands, n = 3 each, and of Cav-3 bands in (D) normalized to CSQ bands. (H) Density of Cav-3 in cytosolic fractions of cardiomyocytes 4- and 16-week post-MI normalized to GAPDH in (E). Sample number N = 3 each, N, number of animals; n, number of cells. *P < 0.05 as determined with one-way ANOVA followed by Bonferroni post hoc correction.