BTZ caused loss of MMP and proteasome inhibition with both drugs altered PINK1/Parkin-mediated mitophagy gene expression levels caused perinuclear clustering of mitochondria but did not change mitochondrial dynamics and mitophagy rate in neuronal cells. A: Flow cytometric MMP analysis results after 100 nM BTZ and CFZ treatments for 3 and 24 h in human neuronal cells. RTNN: Rotenone, 10 μM RTNN was used as positive control. B: Relative expression levels of OPA1, MFN1, MFN2, DRP1, FIS1, PINK1, Parkin and SQSTM1 genes after 100 nM BTZ and CFZ treatments for 3 and 24 h in human neuronal cells. C: Representative images of cellular localization of mitochondria and lysosomes under the confocal microscope after 100 nM BTZ and CFZ treatment for 3 and 24 h in human neuronal cells. White arrows indicate perinuclear clustering of mitochondria. Scale bar 20 μm. D: Quantification of mitochondria and lysosomes colocalization. E-G: Quantification of mitochondrial networks, number of individual mitochondrial structures and number of branches per network after 100 nM BTZ and CFZ treatments for 3 and 24 h in human neuronal cells. Data represent means ± SEM, n = 3, *p < 0.05 versus control group, **p < 0.01 versus control group, ##p < 0.01 versus BTZ group, & p < 0.01 versus to all groups. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)