Figure 8.

pan-Caspase inhibition does not block degeneration induced by BDNF deprivation. A, DRG explants cultured in NGF or BDNF were maintained in trophic media or were withdrawn from trophic support with or without pan-caspase inhibitor Boc-D-fmk (10 μm) for 24 h before fixing, immunostaining for βIII-tubulin, and imaging by epifluorescence microscopy. NGF scale bar: 1000 μm; BDNF scale bar: 500 μm. B, Quantification of axonal area as a function of the distance from the soma was performed using Axoquant 2.0 (Johnstone et al., 2018) and plotted in 500-μm binned segments relative to 0–500 μm NGF/BDNF controls. Pan-caspase inhibitor Boc-D-fmk rescued degeneration induced by NGF deprivation but not by BDNF deprivation. The relative axonal area was analyzed by two-factor ANOVA followed by Tukey’s post hoc comparison and plotted with mean and SEM (n = 3 for each condition; data shown are representative of three independent experiments); *ctr. versus dep. 24 h; #dep. 24 h versus dep. 24 h + Boc-D-fmk; ns: non-significant, ****p < 0.0001.