Fig. 5: Polyamine pathway deficiency impairs intestinal regeneration in young and old mice.

a, A schematic of 5-FU treatments in old mice with and without DFMO. b, The relative body weight of old mice treated twice with DFMO or vehicle control after a single dose of 5-FU (100 mg kg⁻¹). The body weight of each mouse was normalized to its body weight at the day of injection. n = 5 5-FU + DFMO, n = 5 5-FU − DFMO mice. The data are presented as mean ± s.d. The P value was calculated using the two-tailed Welch’s t-test for timepoint comparison and two-way ANOVA for overall comparisons. c, Left: the representative pictures of IHC staining for pH3 at day 12 following 5-FU (±DFMO). Scale bars, 100 µm. The arrows indicate the pH3⁺ cells. Right: the change in the number of pH3⁺ cells per crypt; n = 5 mice per group. The data are presented as mean ± s.d. The P value was calculated using the two-tailed Welch’s t-test for group comparison. d, Top: a schematic of ODC1 KO induction and 5-FU treatment. Bottom: the relative body weight of young ODC1 KO and WT mice treated with a single dose of 5-FU. The body weight of each mouse was normalized to its body weight at the day of injection. n = 4 ODC1 KO, n = 3 ODC1 WT mice. The data are presented as mean ± s.d. The P value was calculated using the two-tailed Welch’s t-test for timepoint comparison and two-way ANOVA for overall day, treatment and day x treatment comparisons. e, The representative H&E stainings of ODC1 KO and WT small intestines at 7 days post 5-FU injection. Scale bars, 50 µm. f, The quantification of the number of crypts per millimetre of small intestine in the indicated groups (7 dpi). Each dot represents one mouse. n = 3 5-FU ODC1 WT group; n = 4 5-FU ODC1 KO group. The data are presented as mean ± s.d. The P value was calculated by the two-tailed Welch’s t-test. g, The quantification of the number of cells per micrometre of villus in the indicated groups (7 dpi). Each dot represents one mouse. n = 3 5-FU ODC1 WT group; n = 4 5-FU ODC1 KO group. The data are presented as mean ± s.d. The P value was calculated by the two-tailed Welch’s t-test. h, A comparison of protein fold changes (FC) induced by 5-FU in ODC1 WT mice (x axis) and the effect of ODC1 KO on 5-FU injected mice (y axis). The proteomics data are from intestinal crypts collected at 7 dpi. The proteins significant (q < 0.05) in both comparisons are plotted. The colour code indicates the sum of the log₂FC from the two comparisons. The number of proteins in each quadrant is indicated. The correlation between the two treatments was assessed using Spearman’s correlation test. n = 3 PBS, n = 3 5-FU mice ODC1 WT group; n = 4 5-FU mice ODC1 KO group. The q values are from Spectronaut differential abundance analysis. i, The effect of ODC1 KO on proteostasis-related proteins. The volcano plots are based on the comparison of ODC1 KO versus WT in 5-FU injected mice. The significantly affected (absolute log₂FC >0.3 and q < 0.05) proteins are shown. n = 3 5-FU mice ODC1 WT group; n = 4 5-FU mice ODC1 KO group. The q values are from Spectronaut differential abundance analysis. Panels a and d created with BioRender.com.

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