Melanocortin 3,5 receptors immunohistochemical expression in colonic mucosa of inflammatory bowel disease patients: A matter of disease activity?

BACKGROUND

Melanocortin 3 and 5 receptors ( MCR and MCR) belong to the melanocortin family. However, data regarding their role in inflammatory bowel diseases (IBD) are currently unavailable.

AIM

This study aims to ascertain their expression profiles in the colonic mucosa of Crohn's disease (CD) and ulcerative colitis (UC), aligning them with IBD disease endoscopic and histologic activity.

METHODS

Colonic mucosal biopsies from CD/UC patients were sampled, and immunohistochemical analyses were conducted to evaluate the expression of MCR and MCR. Colonic sampling was performed on both traits with endoscopic scores (Mayo endoscopic score and CD endoscopic index of severity) consistent with inflamed mucosa and not consistent with disease activity ( normal appearing mucosa).

RESULTS

In both CD and UC inflamed mucosa, MCR (CD: + 7.7 fold normal mucosa, < 0.01; UC: + 12 fold normal mucosa, < 0.01) and MCR (CD: + 5.5 fold normal mucosa, < 0.01; UC: + 8.1 fold normal mucosa, < 0.01) were significantly more expressed compared to normal mucosa.

CONCLUSION

MCR and MCR are expressed in the colon of IBD patients. Furthermore, expression may differ according to disease endoscopic activity, with a higher degree of expression in the traits affected by disease activity in both CD and UC, suggesting a potential use of these receptors in IBD pharmacology.