Journal: iScience
Article Title: Light-evoked activity and BDNF regulate mitochondrial dynamics and mitochondrial localized translation in CNS axons
doi: 10.1016/j.isci.2025.113563
Figure Lengend Snippet: Activity regulates mitochondrial localized protein translation in axons (A) Representative images collected of P15 retinas, after in vivo intravitreal injections of TTX or BSS (control) at P11 and P13, and an injection of EU or OPP 2 h before tissue processing. (B) Cell viability of TTX treated RGCs, identified as Calcein-AM positive and Sytox negative, and normalized to total cell number by Hoescht. Graphed as a percent change relative to control cells (Error bars indicate SEM; 9 replicates; Student’s t test). (C) Confocal images of cultured RGCs, virally labeled with mitochondrial targeted dsRed and pulsed OPP for 15 min before fixation. OPP is detected in RGC cell bodies and in axons. (D) Axon tips demonstrate OPP puncta throughout, growth cones, and terminal axon domains. Axon tips labeled with phalloidin in far red. (E) Representative image of mitochondria, OPP, and ribosomal protein S3 colocalization within axons (scale bar 5 μm). (F) Mander’s coefficient values for colocalizations (error bars indicate SEM; n = 9 blind selected axons from N = 3 replicate RGC preps; one-way ANOVA with Holm-Sidak’s t-test). (G) TEM evidence of ribosomal protein S3 localization with mitochondria in axons, in vivo . The yellow circle represents an axonal area identified by ensheathing myelin structures, and the red arrows show all detectable S3 puncta identified by gold antibody labeling. (H) Correlation of OPP-mitochondrial colocalization relative to mitochondrial size (regression line and 95% confidence intervals are plotted, data points from n = 30 blind selected cells selected across N = 3 replicate RGC preps). (I) Representative images of mitochondrial and OPP-labeled axons in vehicle control, TTX, and TTX+BDNF treated RGCs (scale bar 5um). (J) Number of OPP puncta per 100 μm of axon termini, treated with BDNF, TTX, TTX+BDNF, cycloheximide, and vehicle controls (error bars indicate SEM; >10 blind selected axons from replicate RGC preps; one-way ANOVA with Tukey’s multiple comparisons test, ∗ p < 0.05). (K) Mean mitochondrial size in RGC axons incubated with TTX, BDNF, TTX+BDNF, or vehicle controls (error bars indicate SEM; >10 blind selected axons from replicate RGC preps; one-way ANOVA with Dunn’s multiple comparisons test, ∗ p < 0.05). See , for example, EU labeling and thresholding or masks used in mitochondrial area, OPP spot counts, colocalization, and TEM analyses.
Article Snippet: The homogenate was then spun at 1000g and the supernatant was removed for subsequent magnet based mitochondrial isolation according to Milteny Biotec’s Mitochondrial Isolation Kit.
Techniques: Activity Assay, In Vivo, Control, Injection, Cell Culture, Labeling, Antibody Labeling, Incubation