PHB complex disruption, OMA1 activation and increased OPA1 processing in hearts of Chchd10^S59L/+ mice. (A) BN-PAGE analysis of heart homogenates from Chchd10^S59L/+ mice (S59L/+) and control littermates (+/+) performed with an anti-PHB2 antibody. Loading control was performed with an antibody against UQCRC2 (Complex III CIII). (B) Expression level of YME1L protein analysed by western blotting in heart tissue from Chchd10^S59L/+ mice (S59L/+) and control littermates (+/+). The premature (pm, 75 kDa) and mature (m, 63 kDa) forms of YME1L are indicated. Antibodies against HSP60 and GAPDH were used for loading control. (C) Quantification performed from three independent experiments with three Chchd10^S59L/+ mice and three control littermates. (D) Representative western blot of OMA1 protein performed with heart lysates from Chchd10^S59L/+ mice (S59L/+) and control littermates (+/+). The premature (pm, 60 kDa) and active (47 kDa) forms of OMA1 are indicated. Antibodies against HSP60 and GAPDH were used for loading control. (E) Quantification performed from three independent experiments with three Chchd10^S59L/+ mice and three control littermates. (F) Expression level of L-OPA1 forms (L: the two highest bands) and S-OPA1 (S: the three lowest bands) analysed by western blotting in heart tissues from Chchd10^S59L/+ mice (S59L/+) and control littermates (+/+). (G) Quantification (from four independent experiments with three Chchd10^S59L/+ mice and three control littermates) of L-OPA1/S-OPA1 ratios. (H) BN-PAGE analysis of heart homogenates from Chchd10^S59L/+ mice (S59L/+) and control littermates (+/+) performed with antibodies against GRIM19 (complex I, CI), SDHA (complex II, CII), UQCRC2 (complex III, CIII), MTCO2 (complex IV, CIV) and ATBP (complex V, CV) (three independent experiments). (I) TUNEL staining of heart sections from Chchd10^S59L/+ mice (S59L/+) and control littermates (+/+). Scale bar = 100 µm. (J) Quantification of TUNEL-positive cells observed in I. Values are mean ± SEM from three independent experiments performed with three Chchd10^S59L/+ mice and three control littermates. For each animal, 40–68 visual fields were randomly selected to quantify the number of apoptotic cells.