Comparative analysis of key pathogenic factors of inflammatory bowel disease in <i>in vitro</i> and <i>in vivo</i> models

BACKGROUND: Inflammatory bowel diseases are characterized by inflammation of the intestinal mucosa and increased intestinal barrier permeability. When studying the biological effects of drugs, it is important that experimental models adequately reproduce the key pathogenic factors of the disease. AIM: The work aimed to compare the parameters of intestinal epithelial barrier permeability and inflammatory response in inflammatory bowel disease models: Caco-2 cells stimulated with lipopolysaccharides and mice with a knockout of the mucin 2 gene (Muc2–/–). METHODS: In the in vitro model of inflammatory bowel disease, Caco-2 cells were cultured in the presence of lipopolysaccharide at concentrations ranging from 0.1 to 100.0 μg/mL, and its effects on transepithelial electrical resistance, monolayer permeability, expression of the tight junction genes ZO-1 and Claudin-1 and the pro-inflammatory cytokines IL-8 and TNF-α, as well as IL-8 secretion, were evaluated. In the in vivo model of inflammatory bowel disease, mice with a knockout of the mucin 2 gene (Muc2–/–) were used. Intestinal permeability was determined by plasma fluorescein isothiocyanate-dextran concentration after intragastric administration. Histological analysis of colon samples was performed, with evaluation of TNF-α, IL-1β, and IL-10 gene expression and IL-1β and IL-10 protein levels. RESULTS: In in vitro experiments on Caco-2 cells, lipopolysaccharide at a concentration of 10 μg/mL reduced transepithelial electrical resistance by 57% and increased monolayer permeability to fluorescein isothiocyanate-dextran by 38%. At the same time, it increased IL-8 and TNF-α expression 2.8- and 2.3-fold, decreased ZO-1 and Claudin-1 expression by 54% and 53%, and increased IL-8 secretion 27-fold compared with the control. In vivo, intestinal permeability in Muc2–/– mice was 5.8-fold higher; IL-1β and TNF-α expression was 9.9- and 6.8-fold higher; IL-10 expression in Muc2–/– mice was 71% lower; IL-1β content in the colon was 94% higher, and IL-10 content was 44% lower compared with healthy mice. CONCLUSION: The studied in vitro and in vivo models of inflammatory bowel disease exhibit similar trends in intestinal permeability and inflammatory response parameters. These models adequately reproduce the relevant pathogenic factors and complement each other.