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

Figure 1 Melanocortin 3 receptor expression in samples from individuals with Crohn’s disease. A and B: Representative histological sections stained with haematoxylin-eosin for normal (A) and inflamed (B) mucosa. The blue arrow highlights the dense chronic inflammatory infiltrate, while the black arrow indicates histological activity with cryptitis and microabscesses; C and D: Immunohistochemical staining in the former (C) and latter (D) is also depicted. The rate of Melanocortin 3 receptor (MC₃R) cell positivity, as determined by immunohistochemistry, was significantly higher in the inflamed mucosa compared to the normal mucosa; E: The data are presented as % ± SEM of MC₃R positive cells relative to the total cells counted. Scale bar = 500 µm. ^aP < 0.01.

Figure 2 Melanocortin 3 receptor expression in samples from individuals with ulcerative colitis. A and B: Representative histological sections stained with haematoxylin-eosin for normal (A) and inflamed (B) mucosa. The blue arrow highlights the dense chronic inflammatory infiltrate, while the black arrow indicates histological activity with cryptitis; C and D: Immunohistochemical staining in the former (C) and latter (D) is also presented. The rate of Melanocortin 3 receptor (MC₃R) cell positivity, determined through immunohistochemistry, was significantly higher in the inflamed mucosa compared to the normal mucosa; E: The data are expressed as % ± SEM of MC₃R positive cells relative to the total cells counted. Scale bar = 500 µm. ^aP < 0.01.

Figure 3 Melanocortin 5 receptor expression in samples from individuals with Crohn's disease. A and B: Representative histological sections stained with haematoxylin-eosin for normal (A) and inflamed (B) mucosa. The blue arrow highlights the dense chronic inflammatory infiltrate, while the black arrow indicates histologic activity with microabscesses; C and D: Immunohistochemical staining in the former (C) and latter (D) is also presented. The rate of Melanocortin 5 receptor (MC₅R) cell positivity, determined through immunohistochemistry, was significantly higher in the inflamed mucosa compared to the normal mucosa; E: The data are expressed as % ± SEM of MC₅R positive cells relative to the total cells counted. Scale bar = 500 µm. ^aP < 0.01.

Figure 4 Melanocortin 5 receptor expression in samples from individuals with ulcerative colitis. A and B: Representative histological sections stained with haematoxylin-eosin for normal (A) and inflamed (B) mucosa. The white arrow highlights the dense chronic inflammatory infiltrate in inflamed mucosa; C and D: Immunohistochemical staining in the former (C) and latter (D) is also presented. The rate of Melanocortin 5 receptor (MC₅R) cell positivity, determined through immunohistochemistry, was significantly higher in the inflamed mucosa compared to the normal mucosa; E: The data are expressed as % ± SEM of MC₅R positive cells relative to the total cells counted. Scale bar = 500 µm. ^aP < 0.01.