Figure 3

ER-mitochondria coupling is reduced in NE-induced hypertrophic cardiomyocytes. A) Representative confocal images of cardiomyocytes stained with MitoTracker green 200 nM for 30 min (Mitochondria, green) and ER-Tracker red 400 nM for 30 min (ER, red), treated with NE 10 μM or IGF-1 100 nM for 24 h. Scale bar: 10 μM. B-C) Quantification of the Manders’ coefficient M1 (fraction of ER in colocalization with mitochondria), or M2 (fraction of mitochondria in colocalization with ER). Data are expressed as mean ± SEM, N = 3, *P < 0.05 vs. Ctrl. D-E) Quantification of the M1 and M2 coefficients within the predefined subcellular regions [perinuclear (peri), central and radial]. Data are expressed as mean ± SEM, N = 3, *P < 0.05 vs. Control. F) Representative confocal images of cardiomyocytes stained for InsP₃R2 (green) and mtHsp70 (red), treated with NE 10 μM for 24 h. Scale bar: 20 μM. G) Quantification of the Manders’ coefficient M1 (InsP₃R2 overlapping mtHsp70) and M2 (mtHsp70 overlapping InsP₃R2). Data are expressed as mean ± SEM, N = 3, **P < 0.01 vs. Ctrl. H) Oxygen consumption rate of cardiomyocytes treated with NE 10 μM or IGF-1 100 nM for 24 h. Data are expressed as mean ± SEM, N = 6, *P < 0.05 and **P < 0.01 vs. Control (ctrl).