Fig. 6: Overexpression of SIRT1 rescues the pathogenic phenotypes in A388fs iPSC-CMs through suppressing the ROS-CAMKII-RYR2 pathway.

a, b Western blot analysis of SIRT1, total CaMKII, ox-CaMKII, CaMKII-T286, total RYR2, p-RYR2, and SUN1 expression in II−1 iPSC-CMs overexpressed vector only (negative control, NC), or II-1 iPSC-CMs with SIRT1 overexpression (SIRT1 OE). n = 3 (total CaMKII, ox-CaMKII), 6 (SIRT1, CaMKII-T286, total RYR2, p-RYR2, SUN1) independently biological repeats. c Cellular ROS levels in NC and SIRT1 OE. n = 3 independently biological repeats. d Representative Ca²⁺ transient traces recorded from NC and SIRT1 OE. e Bar graphs to compare the Ca²⁺ transient amplitude and diastolic [Ca²⁺]_i between the two groups in d. n = 20 (II−1-OE), 22 (II−1-NC) cells. f Representative traces of cytosolic Ca²⁺ fluorescence in NC and SIRT1 OE in NT solution and exposed to 0 Na⁺, 0 Ca²⁺ solution containing Tet and Caff. g Bar graphs to compare the RYR2-mediated SR Ca²⁺ leak and SR Ca²⁺ load between the two groups in f. n = 25 (II-1-OE), 28(II−1-NC) cells. h Representative electrophysiological measurements of spontaneous action potentials in NC and SIRT1 OE. i Bar graph to compare the occurrence of arrhythmias between the two groups in h. j Representative graphs of staining of lamin A/C (green) and cardiac-specific marker TNNT2 (red) in NC and SIRT1 OE. DAPI indicates nuclear staining (blue). Scale bar, 20 μm. k Bar graph to compare the occurrence of abnormal NE structure between the two groups in j. n = 6 views from 3 independent experiments. Data are presented as mean ± SEM in b, c, e, g, k. p values were calculated by two-sided unpaired t-test in b, c, e, g, k. Source data are provided as a Source Data file.