Of interest, the number of CD206 positive cells in the damaged mucosa was significantly higher in chronic patients than recently diagnosed patients. No significant differences in the proportion of CD86+/CD68+ cells nor CD206+/CD68+ cells were observed between the damaged and non-damaged mucosa of newly diagnosed patients (Figure 5C). However, a significant Bioactive compound increase in the proportion of CD206+/CD68+ cells was detected in the damaged mucosa of chronic patients compared with the non-damaged mucosa (Figure 5C). Figure 5 M2 macrophages increase in the mucosa of chronic UC patients. Impaired enterocyte differentiation and activation of Wnt signalling pathway are observed in the damaged mucosa of chronic UC patients The analysis of the AP activity in the mucosa of chronic UC patients revealed a significant reduction in the enzymatic activity in the damaged mucosa compared with the non-damaged (Figure 6A).

Figure 6 An impaired alkaline phosphatase activity and increased Wnt signalling in damaged mucosa of patients with UC. To study the Wnt signalling pathway in the mucosa of chronic UC patients we first analysed the expression of Wnt1 by immunohistochemistry. Wnt1 immunostaining was detected in cells infiltrating the lamina propria and a slight staining was also observed in epithelial cells. Interestingly, double immunostaining revealed the co-localization of Wnt1 and CD206 demonstrating the expression of Wnt1 by M2 macrophages in the mucosa of UC patients (Figure 6B).

Immunohistochemistry for ��-catenin showed the presence of nuclear staining in epithelial cells of the mucosa located at the base of the crypts and it decreased as cells move towards the top of the crypts (Figure 6C). The detection of nuclear immunostaining of c-Myc in epithelial cells of the same crypt in consecutive slides (Figure 6C) suggest that the Wnt signalling pathway is active in epithelial cells of the damaged mucosa of UC patients. A quantitative analysis revealed a significant increase in both total and nuclear protein levels of ��-catenin (Figure 6D) and mRNA expression of Lgr5 and c-Myc in damaged mucosa vs non-damaged mucosa (Figure 6F). In addition, immunoprecipitation experiments revealed an increase of ��-catenin bound to Tcf-4 in damaged mucosa vs non-damaged (Figure 6E), further reinforcing that Wnt signalling pathway is stimulated in the damaged tissue. The specific study of Wnt signalling in the damaged mucosa highlighted a relationship between M2 macrophages and epithelial Wnt pathway. Quantification of ��-catenin staining revealed a higher intensity in the damaged than in the non-damaged Brefeldin_A mucosa and results show a positive and significant correlation between the number of M2 macrophages and the intensity of epithelial ��-catenin staining (Figure 6G).