Fig. 7
Disruption of the gut–blood barrier in vitiligo aggravates HA rise in the skin and direct binding to protein NOS2 and MAPK14. A Representative histological images of the small intestine using H&E and alcian blue staining in non-induction and vitiligo mice. Scale bars, 50 µm. B Quantification of small intestine thickness in non-induction (n = 6) and vitiligo mice (n = 6). Mean and SEM. C Quantification of the number of goblet cells per unit length in the small intestine from non-induction (n = 6) and vitiligo mice (n = 6). Mean and SEM. D Intestinal permeability was assessed by measuring the percentage of fluorescent FITC-dextran (4 kDa) translocation into the circulation following oral gavage. Mean ± SEM from three independent experiments, including non-induction and vitiligo mice treated with water (n = 4) or ABX (n = 4). E Measurement of HA levels translocated into circulation 4 h post-oral gavage in non-induction and vitiligo mice treated with water and ABX, n = 4 mice/group. Mean and SEM. Padj = 0.0004 for non-induction-water versus vitiligo-water, Padj < 0.0001 for non-induction-ABX versus vitiligo-water, and Padj < 0.0001 for vitiligo-water versus vitiligo-ABX. F Schematic diagram illustrating the reverse virtual molecular docking using whole and part databases (created with BioRender.com). G Ridgeline plot showing the smoothed density distribution of binding proteins with their binding scores. H Significant Gene Ontology (GO) terms enriched with the respective − log10(FDR). I The proteins with binding scores (absolute value > 7) from the whole and part databases based on simulated molecular docking are shown. J Network diagram illustrating oxidative stress-related proteins with binding scores (absolute value > 7) from the simulated molecular docking. K Differential scanning fluorimetry (DSF) analysis showing the effects of various concentrations of hippuric acid on the melting temperature (Tm) of proteins (NOS2, MPO, and MAPK14) with protein concentrations ranging from 0 to 500 µM. L Surface plasmon resonance (SPR) analysis demonstrated the direct interaction between hippuric acid and the proteins (NOS2, MPO, and MAPK14). Statistical significance was determined using unpaired t test (B, C) or two-way ANOVA test (D, E) followed by Tukey’s post hoc test. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001