Figure 6.
Miro proteins regulate mitochondrial movement in astrocyte processes. Astrocytes were transfected with plasmids encoding a membrane-targeted-mCherry fluorescent protein driven by the minimal GFAP promoter (GFAABC1D:mCherry) and (A) EGFP-mito, (B) EGFP-Miro1, (C) EGFP-Miro1KK, (D) EGFP-Miro2, or (E) EGFP-Miro2KK. The movement of labeled mitochondria was tracked in subfields of astrocyte processes. Kymographic representations depict the movement of mitochondria in these processes over a 15 min imaging epoch (time increases down page). Stationary mitochondria are seen as straight lines and moving mitochondria as diagonal lines. Scale bar, 10 μm. F, Bar chart represents the percentage of mitochondria that were mobile during the imaging epoch, normalized to the total number of mitochondria that were visualized during that period. Results are mean ± SEM. G, Bar chart represents the average displacement of individual mobile mitochondria. H, Bar chart represents the mean maximal instantaneous velocity of individual mitochondria that were mobile within astrocytes. I, Bar chart represents the mean lengths of astrocyte mitochondria across transfection conditions (mobile and stationary). *p < 0.05 (ANOVA with Bonferroni's multiple comparisons test).