Extended Data Fig. 5: Inactivation of Sarm1 preserves axonal integrity and suppresses inflammation in npp tumours following experimental injury.
From: Axonal injury is a targetable driver of glioblastoma progression
a, Representative images of intermediate npp tumours generated in WT and Sarm1-/- mice, stained for neurofilament (NF, yellow) 2 weeks following Sham injury or transection of tumour-ipsilateral corpus callosum axons (Injury, see timeline in Fig. 4a). Scale bar=1 mm. White box indicates the injury site region depicted at high magnification on the right. Note significant axonal protection in Sarm1-/- animals even at the site of injury demarcated by the star symbol. Scale bar=200 μm. Images are representative of n = 3 mice per condition. b, Representative immunofluorescence images of npp tumours generated in WT and Sarm1-/- animals and subjected to Sham or Injury at 4.5 weeks, 8.5 weeks or 12.5 weeks after tumour induction (see timeline in Fig. 4a). tdTomato+ tumour cells are in red; sections were stained for EdU (grey) and DAPI (blue). Scale bar=200 μm. WT Sham n = 6, WT Injury n = 6, Sarm1-/- Sham n = 6, Sarm1-/- Injury n = 7 at 4.5 weeks, WT Sham n = 7, WT Injury n = 7, Sarm1-/- Sham n = 7, Sarm1-/- Injury n = 6 at 8.5 weeks; WT Sham n = 7, WT Injury n = 6, Sarm1-/- Sham n = 7, Sarm1-/- Injury n = 6 mice at 12.5 weeks. c, Quantification of the percentage of EdU+ tumour cells at the injury site in samples from b. Shown is the fold change relative to corresponding brain region in Sham tumour mice at each time point. Mean ± SEM. Multiple two-sided unpaired t tests. WT Sham n = 6, WT Injury n = 6, Sarm1-/- Sham n = 6, Sarm1-/- Injury n = 7 at 4.5 weeks, WT Sham n = 7, WT Injury n = 7, Sarm1-/- Sham n = 7, Sarm1-/- Injury n = 6 at 8.5 weeks; WT Sham n = 7, WT Injury n = 6, Sarm1-/- Sham n = 7, Sarm1-/- Injury n = 6 mice at 12.5 weeks. p = 0.0094 (Sarm1-/- sham vs Sarm1-/- injury site). d, Representative images of GFAP (turquoise), Iba1 (magenta) and CD68 (yellow) staining within the injury site of npp-tumour bearing WT mice subjected to corpus callosum transection injury at 8.5 weeks post tumour induction. Scale bar=200 μm. Sham n = 6, WT Injury n = 6, Sarm1-/- Sham n = 6, Sarm1-/- Injury n = 9 at 4.5 weeks, WT Sham n = 7, WT Injury n = 6 (e) and 8 (f), Sarm1-/- Sham n = 8 (GFAP) and 7 (Iba1/CD68), Sarm1-/- Injury n = 8 at 8.5 weeks; WT Sham n = 7, WT Injury n = 8, Sarm1-/- Sham n = 5, Sarm1-/- Injury n = 6 (GFAP) and 7 (Iba1/CD68) mice at 12.5 weeks. e-f, Quantification of GFAP area (e) and CD68 intensity (f) at the injury site of samples described in b. Shown is the fold change relative to corresponding brain region in Sham tumour mice at each time point. Mean ± SEM. Multiple two-sided unpaired t tests. In e, p < 0.0001 at both 4.5 and 8.5wk WT Sham vs WT Injury (injury site). In f, p = 0.012 (4.5wk) and p = 0.0016 (8.5wk) WT Sham vs WT Injury (injury site). Sham n = 6, WT Injury n = 6, Sarm1-/- Sham n = 6, Sarm1-/- Injury n = 9 at 4.5 weeks, WT Sham n = 7, WT Injury n = 6 (e) and 8 (f), Sarm1-/- Sham n = 8 (e) and 7 (f), Sarm1-/- Injury n = 8 at 8.5 weeks; WT Sham n = 7, WT Injury n = 8, Sarm1-/- Sham n = 5, Sarm1-/- Injury n = 6 (e) and 7 (f) mice at 12.5 weeks.
