Fig. 5: DR5 loss induces excessive apoptosis of Paneth cells and TA cells.

Data were expressed as mean ± SEM. Statistical analyses were performed by the unpaired t-tests or two-way ANOVA followed by Sidak’s multiple comparisons test (*P < 0.05, ***P < 0.001, ****P < 0.0001). A The analysis of KEGG apoptosis signalling pathway gene set based on RNA-seq. The top 20 genes are listed in the heatmap, which shows that the expression of apoptosis related genes is upregulated in intestinal crypts of DR5^-/- mice compared with that of WT mice (n = 3). In this scheme, deep red corresponds to heightened gene expression levels, while light blue denotes lower expression. B Western blot was performed to quantify the cleaved caspase-3 protein expression in ileal crypts from WT mice and DR5^-/- mice (n = 4). C Representative pictures of staining of Lyz, TUNEL, and DAPI (nuclei) in ileum of WT mice and DR5^-/- mice (scale bars: 100 μm). The red arrows indicate TUENL⁺ Paneth cells, and the white arrows indicate the TUNEL⁺ TA cells. D Statistical analysis to show the difference of the TUENL⁺ Paneth cells and TUNEL⁺ TA cells between WT mice and DR5^-/- mice (n = 6). At least 20 crypts were counted randomly for each slide and the mean value was calculated. E Representative images showing organoids derived from crypts of WT and DR5^-/- mice 72 h after culture (scale bars: 500 μm). F Dynamic changes of organoid survival in WT and DR5^-/- mice (n = 6). For each sample, four 40-fold visual fields were randomly selected to count the number of organoids under each visual field, and the average value was obtained. The number of organoids at different time points was normalized with the number of organoids at 0 h to reflect the organoid survival rate. G Immunofluorescence co-labelled Lyz and DR5 in ileum. The red arrows indicate the DR5⁺ Paneth cells and the yellow arrow indicates DR5⁺ ISC in the basement of crypt (scale bar: 50 μm).