Fig. 2
Mitochondrial membrane potential is depolarized in VCPR191Q/wt mitochondria. A The mitochondrial membrane potential (\({\Delta \Psi }_{m}\)) was measured by live cell imaging using TMRM, a cationic fluorescent dye, in non-quenching mode. TMRM accumulates in the mitochondrial matrix based on the mitochondrial membrane potential. In unhealthy (depolarized) mitochondria, the matrix carries comparatively fewer negative charges and consequently, less TMRM accumulates. Oligomycin A, an ATPase inhibitor causing hyperpolarization, and FCCP, a mitochondrial uncoupler causing mitochondrial depolarization, are used as positive and negative controls respectively. Abbreviations: outer mitochondrial membrane (OMM) and inner mitochondrial membrane (IMM). B Representative fluorescent microscopy images of mitochondria labelled with TMRM at baseline conditions. Scale bar: 20 µm. C TMRM mean intensity quantifications for baseline, oligomycin A (positive control) and FCCP (negative control) conditions from the TMRM images shown in B. Means ± SEM are shown; dots represent individual wells measured across four independent experiments. Statistical significance was evaluated by Two-way ANOVA with Bonferroni correction for multiple comparisons; ns p > 0.05, ****p < 0.0001