Fig. 1: Radiation-induced epithelial thinning and basal cell depletion in human and murine glossal mucosa.

a Glossal tissue specimens were collected from patients with head and neck malignant tumors undergoing surgery after radiotherapy. Created in BioRender. Yu, W. (2025) https://BioRender.com/xwdxw8b. b Changes in the glossal mucosa analyzed using hematoxylin and eosin (H&E) staining (n = 6 human samples). Epithelial depth was measured on H&E-stained sections by identifying the basal epithelial layer (cuboidal cells with hyperchromatic nuclei and tightly packed arrangement), and then quantifying the vertical distance from the basement membrane (a wavy boundary separating the epithelium from the stroma) to the epithelial surface. ▲ represents the boundary between the epithelium and stroma, * represents disruption of epithelial continuity. Scale bar, 500 μm. c Immunohistochemistry of human glossal tissue using Keratin 19 (KRT19) showed changes in epithelial thickness and morphology (n = 6 human samples). Scale bar, 500 μm. d Proliferating cell nuclear antigen (PCNA) immunofluorescence staining of human glossal tissue before and after exposure to ionizing radiation (n = 6 human samples). Scale bar, 500 μm. e Schematic diagram for the construction of a mouse animal model of radiation-induced oral mucositis. Created in BioRender. Yu, W. (2025) https://BioRender.com/j8wb6pl. f H&E staining of mouse tongues before and after irradiation. ▲ represents the boundary between the epithelium and stroma, * represents disruption of epithelial continuity (n = 10 mice). Three random images per mouse were analyzed. Scale bar, 100 μm. g Sections from normal murine glossal mucosa and ulcerated areas near irradiated glossal tissues (n = 6 mice). Five random images per mouse were analyzed. Scale bar, 100 μm. h PCNA immunofluorescence staining of murine glossae before and after exposure to ionizing radiation (n = 6 mice). Five random images per mouse were analyzed. Scale bar, 100 μm. i Uniform manifold approximation and projection (UMAP) plots and annotations by major cell type from single-cell transcriptome analysis of murine glossal mucosa before and after irradiation. j Pie charts showing the percentages of different cell types before and after irradiation. k Diagram of the oral mucosal epithelium structure and major cell types. Scale bar, 50 μm. l UMAP plots and annotations by major epithelial cell type from single-cell transcriptome analysis of murine glossal mucosa before and after radiation. m Immunofluorescence depicted major cell types proportion in murine glossal mucosa before and after irradiation (n = 3 mice). Three random images per mouse were analyzed. Data represent the mean ± SD. Scale bar, 50 μm. Statistical significance was determined by unpaired two-tailed Student’s t test (f-h). Statistical significance was determined by Two-way ANOVA analysis with Tukey’s multiple comparisons test (m). Source data are provided as a Source Data file.