Reduced OPA1 protein amount and altered processing in fibroblasts from patients with ADOA. (A) Quantitative western blot against OPA1 (upper panel) and actin (lower panel) of the indicated probes. Arrows indicate the corresponding bands; P/M: precursor/mutant protein, L1 to S5 bands according to Duvezin-Caubet et al. 2007 . (B) Densitometric evaluation of the different OPA1 isoforms from the western blot shown in A as mean ± S.D. from patients vs. control. OPA1 protein levels are reduced in the patients' cell lines and the unequal reduction of the different corresponding OPA1 isoforms suggest altered proteolytic cleavage of OPA1. (C) Quantitative western blot against indicated mitochondrial proteins in total cell lysates of the indicated probes. (D) Densitometric quantification of the western blot shown in C as mean ± S.D. from patients vs. controls. The analysis shows that all tested mitochondrial proteins are less abundant in patients' cell lines compared to controls.