Despite intensive research of inflammatory bowel disease (IBD), there is insufficient and conflicting information in the literature about the expression of IBD molecular factors depending on the location (individual layers), histological picture, microenvironment and stage of inflammation in the intestinal wall. We wanted to check the differences in the expression of selected molecular factors between the histologically healthy intestinal mucosa and the mucosa in IBD and the differences between the individual layers of the histologically healthy intestinal wall. We were also interested in the expression of selected molecular factors in/between individual layers of the intestinal wall in different histological patterns of the disease process.
We used paraffin-embedded samples of mice colon with dextran sodium sulfate-induced colitis in the study. Whole slices of samples were cut or areas within individual layers of the intestinal wall were excised using laser microdissection. We checked the mRNA expression of target genes (TNFα, TNFR, DUOX2, NOS2) and miRNAs (mi-223-3p, miR-181a-5p and miR3473b) and checked their mutual correlations using multivariate analysis.
Results showed that the expression of selected molecular factors can vary depending on the location (between individual layers of the intestinal wall), on the stage of inflammation (histologically healthy intestinal mucosa between healthy and diseased individuals), and on the histological picture (a different histological picture of the disease process). We also showed that the expression determined in whole slices does not necessarily reflect the expression in the mucosa or other layers of the intestinal wall and that the expression pattern is target RNA specific.
As first we provided an insight into the expression of selected molecular factors in relation to the colon microenvironments, with an emphasis on the investigation of individual layers with different histological picture and the stage of inflammation. This gave us an insight into the relations of the investigated molecular factors and offered reasons for the divergence of data in the literature.
|