Impairment of the intestinal epithelium barrier through alteration of proliferation and differentiation balance in alcohol use disorder

Figure 2 Cell proliferation in the crypt base and the transit amplifying zone. A: Immunohistofluorescence staining of duodenal biopsies showing Ki67⁺ proliferating cells (red), lysozyme⁺ Paneth cells (yellow) to identify the crypt base, and DAPI (blue) for the nuclei; B: Ki67⁺ cells were counted in 5-10 crypts per patient. Alcohol use disorder (AUD) patients exhibited a significant increase in proliferating cells within the crypt base. However, when split into 2 subgroups, only AUD-altered patients showed consistently higher proliferation within the crypt base. Healthy (n = 16); AUD normal (n = 18); AUD altered (n = 17); C: Multiplex immunofluorescence for OLFM4 (stem and stem-like cells), Ki67 (red), lysozyme (purple), and DAPI (blue). As indicated in the scheme, the transit amplifying (TA) zone begins at the end of the crypt base and extends to the upper limit of Ki67 staining; D: Ki67⁺ cell numbers in the TA zone were significantly increased in AUD patients, with no significant differences between AUD subgroups. Healthy (n = 11); AUD normal (n = 12); AUD altered (n = 5); E: Quantification of OLFM4⁺ cell distribution along the crypt axis to assess the spatial extension of stem-like cells. OLFM4⁺ distance is significantly increased in AUD altered patients in favor of an extension of stem-like cells into the TA zone. Data are presented as mean ± SD. Healthy (n = 9); AUD normal (n = 9); AUD altered (n = 10). AUD: Alcohol use disorder.